This document (prEN 17180:2024) has been prepared by Technical Committee CEN/TC 102 “Sterilizers and associated equipment for processing of medical devices”, the secretariat of which is held by DIN.

This document is currently submitted for a second CEN Enquiry.

A first draft (prEN 17180:2017) was published in 2017, but the status of the project was set back to a preliminary work item. The following changes were made to the first draft:

— the structure of the main text has been widely adopted to the structure of ISO/TS 22421:2021 and aligned with the current revisions of EN 14180 and EN 1422 in 2022;

— most definitions have been adapted with reference to EN ISO 11139:2018/A1:2024;

— a separate clause ‘Protective measures’ has been implemented for referencing to individual clauses of EN IEC 61010‑2‑040;

— a new Annex G Additional information on protective measures has been added;

— requirements on the control and monitoring system have been merged into a clause and informative illustrations have been provided in an Annex I.

This document has been prepared under a standardization request addressed to CEN by the European Commission. The Standing Committee of the EFTA States subsequently approves these requests for its Member States.

For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this document.

Introduction

This document provides minimum requirements and test methods for sterilizers performing a low temperature sterilization process using a composition of water and hydrogen peroxide (H₂O₂), vaporized, and injected into the sterilizer chamber as sterilizing agent. Vaporized hydrogen peroxide (VH2O2) sterilizers operate typically below 60°C and are primarily used for the sterilization of thermolabile or moisture-sensitive medical devices in health care facilities but can also be used for sterilization of other reusable medical devices that have been established to be compatible with VH2O2 processes. The sterilizers operate automatically using pre-set cycles. VH2O2 sterilizers can also be used by medical device manufacturers during commercial production.

Like the other standardized low temperature sterilization processes VH2O2 sterilization processes are specified by physical and chemical parameters and verified using physical, chemical, and microbiological means. The sterilizers operate automatically using pre-set cycles.

The tests described in this document are reference tests intended to demonstrate conformity with the performance requirements specified in this document. They may be used in type tests, works tests, in validation and re-qualification, or in periodic and routine tests carried out by the user. Validation and routine control of sterilization processes are essential to ensure their efficacy. This document does not cover validation and routine control of a VH2O2 sterilization process. EN ISO 14937:2009 provides general requirements and guidance on validation and routine control of sterilization processes. Specific requirements and guidance for VH202 sterilization processes are given in ISO 22441:2022.

Some VH2O2 sterilizers have processes that demonstrate some level of inactivation of the causative agents of spongiform encephalopathies such as scrapie, bovine spongiform encephalopathy, and Creutzfeldt-Jakob Disease. However, this inactivation is process, cycle, and test protocol specific, and not sterilizer specific, therefore this inactivation is not addressed in this document, and no specific test methods are provided.

Planning and design of products applying to this document should consider not only technical aspects but also the environmental impact from the product during its life cycle. Environmental aspects are addressed in Annex H of this document.

For each normative requirement given in this document, a conformity statement is provided to clarify means of demonstration of conformity to each requirement.

NOTE Specifications on general equipment safety are addressed in EN IEC 61010‑2‑040:2021, and are not repeated in this document. Requirements on occupational safety and health are not specified in this document. National regulations can exist.

1.0 Scope

This document specifies requirements and tests for low temperature hydrogen peroxide sterilizers, using vaporized aqueous solution of hydrogen peroxide as the sterilizing agent.

These sterilizers are used for the sterilization of medical devices, particularly thermolabile medical devices.

This document specifies minimum requirements for:

— the performance and design of sterilizers intended to deliver a process capable of sterilizing medical devices;

— the equipment and controls of these sterilizers needed for operation, control, and monitoring, and which can be used for validation of the sterilization processes;

— the test equipment and test procedures used to verify the sterilizer performance specified by this document.

This document does not specify requirements for sterilizer intended to process liquids, biological waste, or human tissues unless part of a medical device.

This document does not describe a quality management system for the control of all stages of the manufacture of the sterilizer.

NOTE Attention is drawn to the standards for quality management, e.g. EN ISO 13485.

This document does not specify requirements and tests for decontamination systems for use in rooms, enclosures, or environmental spaces.

2.0 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

EN 868‑5:2018, Packaging for terminally sterilized medical devices - Part 5: Sealable pouches and reels of porous materials and plastic film construction - Requirements and test methods

EN 868‑9:2018, Packaging for terminally sterilized medical devices - Part 9: Uncoated nonwoven materials of polyolefines - Requirements and test methods

EN 60584‑1:2013, Thermocouples – Part 1: EMF specifications and tolerances (IEC 60584‑1:2013)

EN IEC 60751:2022, Industrial platinum resistance thermometers and platinum temperature sensors (IEC 60751:2022)

EN 61010‑1:2010,^[1] Safety requirements for electrical equipment for measurement, control, and laboratory use – Part 1: General requirements (IEC 61010‑1:2010)

EN IEC 61010‑2‑040:2021, Safety requirements for electrical equipment for measurement, control, and laboratory use - Part 2-040: Particular requirements for sterilizers and washer-disinfectors used to treat medical materials (IEC 61010 2 040:2020)

EN IEC 61326‑1:2021, Electrical equipment for measurement, control and laboratory use - EMC requirements - Part 1: General requirements (IEC 61326 1:2020)

EN 62366‑1:2015,^[2] Medical devices – Part 1: Application of usability engineering to medical devices (IEC 62366‑1:2015)

EN ISO 3166‑1:2020, Codes for the representation of names of countries and their subdivisions - Part 1: Country code (ISO 3166-1:2020)

EN ISO 3746:2010, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Survey method using an enveloping measurement surface over a reflecting plane (ISO 3746:2010)

EN ISO 11138‑1:2017, Sterilization of health care products - Biological indicators - Part 1: General requirements (ISO 11138-1:2017)

EN ISO 14971:2019,^[3] Medical devices – Application of risk management to medical devices (ISO 14971:2019)

EN ISO 15223‑1:2021, Medical devices - Symbols to be used with information to be supplied by the manufacturer - Part 1: General requirements (ISO 15223-1:2021)

EN ISO 20417:2021, Medical devices - Information to be supplied by the manufacturer (ISO 20417:2021, Corrected version 2021-12)

ISO 22441:2022, Sterilization of health care products — Low temperature vaporized hydrogen peroxide — Requirements for the development, validation and routine control of a sterilization process for medical devices

ISO 639:2023, Code for individual languages and language groups

ISO 2861:2020, Vacuum technology — Dimensions of clamped-type quick-release couplings

ISO 8601‑1:2019, Date and time — Representations for information interchange — Part 1: Basic rules

ISO 8000‑1:2022, Data quality — Part 1: Overview

3.0 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

• IEC Electropedia: available at http://www.electropedia.org/

• ISO Online browsing platform: available at http://www.iso.org/obp

3.1

access device

means by which entry to restricted parts of equipment is achieved

Note 1 to entry: This can be by dedicated key, code, or tool.

[SOURCE: EN ISO 11139:2018, 3.4]

3.2

accompanying information

information accompanying, or marked on, a medical device (3.36) or accessory and containing information for the user or those accountable for the installation, use, maintenance, decommissioning and disposal of the medical device (3.36) or accessory, particularly regarding safe use

Note 1 to entry: The accompanying information can be regarded as part of the medical device (3.38) or accessory.

Note 2 to entry: The accompanying information can consist of the label (3.28), marking (3.33), instructions for use (3.27), technical description, installation manual, quick reference guide, etc.

Note 3 to entry: Accompanying information is not necessarily a written or printed document but could involve auditory, visual, or tactile materials and multiple media types (e.g. CD/DVD-ROM, USB stick, website).

Note 4 to entry: The label (3.28) can include the information on the packaging of the medical device (3.36).

Note 5 to entry: E(electronic)-documentation can include any or all types of information supplied by the manufacturer (3.24) partially or entirely.

Note 6 to entry: Marketing information is also known as promotional material.

[SOURCE: EN ISO 20417:2021, 3.2, modified — The term “processing” has been removed from the definition, Note 1 to entry has been modified to exclude a requirement, Note 4 to entry has been deleted, and Notes 5 to 7 to entry have been renumbered Notes 4 to 6 to entry.]

3.3

automatic controller

device that directs the equipment sequentially through required stages (3.51) of the cycle in response to programmed cycle parameters

[SOURCE: EN ISO 11139:2018, 3.18]

3.4

biological indicator

test system containing viable microorganisms providing a specified resistance to a specified sterilization process

[SOURCE: EN ISO 11139:2018, 3.29]

3.5

calibration

operation that, under specified conditions, in a first step, establishes (3.15) a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish (3.15) a relation for obtaining a measurement result from an indication

[SOURCE: EN ISO 11139:2018, 3.31]

3.6

chamber

part of equipment in which a load is processed

Note 1 to entry: In this document the chamber is the “sterilizer chamber”.

[SOURCE: EN ISO 11139:2018, 3.36, Note 1 to entry has been added]

3.7

chemical indicator

test system that reveals change in one or more pre-specified process variables based on a chemical or physical change resulting from exposure to a process

[SOURCE: EN ISO 11139:2018, 3.43]

3.8

conditioning

treatment of product prior to the exposure phase to attain a specified temperature, relative humidity, or other process variable throughout the load

Note 1 to entry: In this document conditioning is used as conditioning stage.

[SOURCE: EN ISO 11139:2018, 3.58, modified – Note 1 to entry added]

3.9

control

regulation of variables within specified limits

[SOURCE: EN ISO 11139:2018, 3.63]

3.10

cycle complete

message from the automatic controller (3.3) that the operating cycle (3.39) has ended successfully

[SOURCE: EN ISO 11139:2018, 3.71]

3.11

cycle parameter

value of a cycle variable including its tolerance used for control (3.9), monitoring (3.37), indication, and recording of an operating cycle (3.39)

[SOURCE: EN ISO 11139:2018, 3.72]

3.12

cycle variable

property used to control (3.9), monitor, indicate, or record an operating cycle (3.39)

[SOURCE: EN ISO 11139:2018, 3.74]

3.13

desorption

removal of the sterilizing agent from the chamber (3.6) and the load at the end of the exposure stage (3.18)

[SOURCE: EN ISO 11139:2018, 3.78, modified with phase replaced by stage]

3.14

double-ended

having separate doors for loading and unloading in separate areas

[SOURCE: EN ISO 11139:2018, 3.92]

3.15

establish

determine by theoretical evaluation and confirm by experimentation

[SOURCE: EN ISO 11139:2018, 3.107]

3.16

exposure stage

cycle stage (3.51) between the introduction of the sterilizing agent (3.60) or disinfecting agent into the chamber (3.6) and when its microbicidal effect has become negligible

Note 1 to entry: The exposure stage comprises that part of the process for which microbial lethality is claimed.

[SOURCE: EN ISO 11139:2018, 3.111]

3.17

fault

situation in which one or more of the process or cycle parameters is/are outside its/their specified tolerance(s)

[SOURCE: EN ISO 11139:2018, 3.116]

3.18

filter

construct of porous material through which a fluid (3.19) is passed to remove viable and/or non-viable particles

[SOURCE: EN ISO 11139:2018, 3.117]

3.19

fluid

substance that continually deforms (flows) under applied shear force

EXAMPLE Liquid, gas, vapour, plasma.

[SOURCE: EN ISO 11139:2018, 3.120]

3.20

hazard

potential source of harm

[SOURCE: ISO/IEC Guide 51:2014, 3.2]

3.21

hazardous situation

circumstance in which people, property, or the environment is/are exposed to one or more hazards (3.20)

[SOURCE: ISO/IEC Guide 51:2014, 3.4]

3.22

holding time

period during which process or cycle parameters are maintained, within their specified tolerances for defined cycle stages (3.51)

[SOURCE: EN ISO 11139:2018, 3.133]

3.23

indicate

display a value, condition, or stage (3.51) of process

[SOURCE: EN ISO 11139:2018, 3.139]

3.24

information supplied by the manufacturer

all information related to the identification and use of a medical device (3.36) or accessory, in whatever form provided, intended to ensure the safe and effective use of the medical device (3.36) or accessory

Note 1 to entry: For the purposes of this document, shipping documents and promotional material are excluded from information supplied by the manufacturer. However, some authorities having jurisdiction can consider such supplemental information as information supplied by the manufacturer.

[SOURCE: EN ISO 20417:2021, 3.10, modified – Notes 1, 3 and 4 to entry have been deleted, and Note 2 to entry has become Note 1 to entry.]

3.25

inspection

determination of conformity to specified requirements

Note 1 to entry: If the result of an inspection shows conformity, it can be used for purposes of verification (3.64).

Note 2 to entry: The result of an inspection can show conformity or nonconformity (3.6.9) or a degree of conformity.

Note 3 to entry: Inspection can be understood as visual inspection and/or application testing.

Note 4 to entry: References to definitions of determination, conformity and specified requirements are removed.

[SOURCE: EN ISO 9000:2015, 3.11.7, modified – Notes 3 and 4 to entry have been added.]

3.26

installation qualification

process of establishing (3.15) by objective evidence that all key aspects of the process equipment and ancillary system installation comply with the approved specification

[SOURCE: EN ISO 11139:2018, 3.220.2]

3.27

instructions for use

IFU

portion of the accompanying information (3.2) that is essential for the safe and effective intended use of medical device (3.38) or accessory directed to the user of the medical device (3.36)

Note 1 to entry: The instructions for use, or portions thereof, can be located on the display of a medical device (3.36) or its accessory.

[SOURCE: EN ISO 20417:2021, 3.11 modified – ‘package insert’ has been removed, ‘use’ has been changed to ‘intended use’, Notes 1, 2, 4 and 5 to entry have been deleted, and Note 3 to entry has become Note 1 to entry.]

3.28

label

<medical device, accessory> written, printed, or graphic information appearing on the item itself

Note 1 to entry: Label includes the marking (3.33) on the medical device (3.36) or accessory.

[SOURCE: EN ISO 20417:2021, 3.12, modified – Reference to packaging and provision of multiple items has been deleted, Notes 1, 3 and 4 to entry have been deleted, and Note 2 to entry has become Note 1 to entry.]

3.29

labelling

label (3.28), instructions for use (3.27) and any other information related to identification, technical description, intended purpose and proper use of the medical device (3.36), but excluding shipping documents

[SOURCE: EN ISO 13485:2016, 3.8]

3.30

load

product, equipment, or materials to be processed together within an operating cycle (3.39)

[SOURCE: EN ISO 11139:2018, 3.155]

3.31

load configuration

distribution and orientation of a load (3.30)

[SOURCE: EN ISO 11139:2018, 3.156]

3.32

loading door

means of access through which a load (3.30) is passed into the chamber (3.6) before processing

[SOURCE: EN ISO 11139:2018, 3.157]

3.33

marking

information, in text or graphical format, durably affixed, printed, etched (or equivalent) to a medical device (3.36) or accessory

Note 1 to entry: For the purposes of this document, marking is different from “direct marking” as described in systems for unique device identification (UDI) of medical devices (3.36).

[SOURCE: EN ISO 20417:2021, 3.16 modified – Notes 1 and 3 to entry have been deleted. Note 2 to entry has been modified and renumbered as Note 1 to entry.]

3.34

measurement uncertainty

non-negative parameter characterizing the dispersion of the quantity values being attributed to a measurand, based on the information used

[SOURCE: EN ISO 11139:2018, 3.164]

3.35

measuring chain

series of elements of a measuring instrument or measuring system, which constitutes the path of the measurement signal from the input (quantity subject to measurement) to the output (the result of the measurement)

[SOURCE: EN ISO 11139:2018, 3.165]

3.36

medical device

instrument, apparatus, implement, machine, appliance, implant, reagent for in vitro use, or software material, or other similar or related article, intended by the manufacturer to be used, alone or in combination, for human beings, for one or more of the specific medical purpose(s) of:

— diagnosis, prevention, monitoring (3.37), treatment, or alleviation of disease;

— diagnosis, monitoring (3.37), treatment, alleviation of, or compensation for an injury;

— investigation, replacement, modification, or support of the anatomy, or of a physiological process;

— supporting or sustaining life;

— control of conception;

— disinfection of medical devices;

— providing information by means of in vitro examination of specimens derived from the human body;

and does not achieve its primary intended action by pharmacological, immunological, or metabolic means, in or on the human body, but which may be assisted in its intended function by such means

Note 1 to entry: Products which may be considered to be medical devices in some jurisdictions, but not in others include:

— items specifically intended for cleaning or sterilization of medical devices;

— pouches, reel goods, sterilization wrap, and reusable containers for packaging of medical devices for sterilization;

— disinfection substances;

— aids for persons with disabilities;

— devices incorporating animal and/or human tissues;

— devices for in vitro fertilization or assisted reproduction technologies.

[SOURCE: EN ISO 11139:2018, 3.166]

3.37

monitoring

continual checking, supervising, critically observing, or determining the status, in order to identify change from the performance level required or expected

[SOURCE: EN ISO 11139:2018, 3.180]

3.38

normal operation

use of equipment in accordance with the manufacturer’s instructions and with all process parameters (3.44) within the specified tolerances

[SOURCE: EN ISO 11139:2018, 3.185]

3.39

operating cycle

complete set of stages (3.51) of a process that is carried out, in a specified sequence

Note 1 to entry: Loading and unloading are not part of the operating cycle

[SOURCE: EN ISO 11139:2018, 3.188]

3.40

operating pressure

fluid (3.21) pressure occurring during an operating cycle (3.39)

[SOURCE: EN ISO 11139:2018, 3.189]

3.41

operating temperature band

<operating>range of temperatures expressed as the minimum and maximum temperatures in the usable chamber space during a holding time (3.22)

Note 1 to entry: An operating cycle (3.39) can comprise more than one holding time (3.22).

[SOURCE EN ISO 11139:2018, 3.293.1/Amd1:2024]

3.42

operational qualification

process of obtaining and documenting evidence that installed equipment operates within predetermined limits when used in accordance with its operational procedures

[SOURCE: EN ISO 11139:2018, 3.220.3]

3.43

penetration type test device

PTTD

device for use in type tests (3.61) to ascertain a minimum sterilizing agent (3.60) penetration performance during a sterilization cycle

[SOURCE: EN ISO 11139:2018, 3.358]

3.44

process parameter

specified value for a process variable (3.45)

Note 1 to entry: The specification for a process includes the process parameters and their tolerances.

[SOURCE: EN ISO 11139:2018, 3.211]

3.45

process variable

chemical or physical attribute within a cleaning, disinfection, packaging, or sterilization process, changes in which can alter its effectiveness

EXAMPLE Time, temperature, pressure, concentration, humidity, wavelength.

[SOURCE: EN ISO 11139:2018, 3.213]

3.46

recorder

equipment that records and produces a permanent record of information graphically, digitally, or electronically

[SOURCE: EN ISO 11139:2018, 3.224]

3.47

reference measurement point

location of the sensor controlling the operating cycle (3.39)

[SOURCE: EN ISO 11139:2018, 3.227]

3.48

safety data sheet

SDS

document specifying the properties of a substance, its potential hazardous effects for humans and the environment, and the precautions necessary to handle and dispose of the substance safely

[SOURCE: EN ISO 11139:2018, 3.239]

3.49

serial number

production control (3.9) containing a combination of letters or numbers, selected by the manufacturer, intended for quality control (3.9) and identification purposes to uniquely distinguish an individual medical device (3.36) from other medical devices (3.36) with the same catalogue number or model number

[SOURCE: EN ISO 20417:2021, 3.22]

3.50

services

supplies from an external source needed for the function of equipment

EXAMPLE Electricity, sterilant, compressed air, drainage.

[SOURCE: EN ISO 11139:2018, 3.252, modified – EXAMPLE has been added]

3.51

stage

<operating cycle> part of an operating cycle (3.39) with a specified function

EXAMPLE Air removal stage, plateau period, drying stage, final air admission stage.

[SOURCE: EN ISO 11139:2018, 3.262]

3.52

sterilant

chemical or combination of chemicals used to generate a sterilizing agent (3.60)

[SOURCE: EN ISO 11139:2018, 3.268]

3.53

sterilant/ sterilizing agent injection

introduction of sterilant/sterilizing agent into the evacuated chamber (3.6) until the set operating pressure (3.40) has been attained or the specified quantity of sterilant/sterilizing agent has been delivered

[SOURCE: EN ISO 11139:2018, 3.269]

3.54

sterile

free from viable microorganisms

Note 1 to entry: For “free from viable microorganisms” see EN 556‑1.

[SOURCE: EN ISO 11139:2018, 3.271, modified – Note 1 to entry has been added.]

3.55

sterile barrier system

SBS

minimum package that minimizes the risk of ingress of microorganisms and allows aseptic presentation of the sterile product at the point of use

[SOURCE: EN ISO 11139:2018, 3.272]

3.56

sterilization

validated process used to render product free from viable microorganisms

Note 1 to entry: In a sterilization process (3.58), the nature of microbial inactivation is exponential and thus the survival of a microorganism on an individual item can be expressed in terms of probability. While this probability can be reduced to a very low number, it can never be reduced to zero.

[SOURCE: EN ISO 11139:2018, 3.277]

3.57

sterilization cycle

predetermined sequence of stages (3.51) performed in a sterilizer (3.59) to achieve product free of viable microorganisms

[SOURCE: EN ISO 11139:2018, 3.279]

3.58

sterilization process

series of actions or operations needed to achieve the specified requirements for sterility

Note 1 to entry: This series of actions includes pre-treatment of product (if necessary), exposure under defined conditions to the sterilizing agent (3.60), and any necessary post treatment.

[SOURCE: EN ISO 11139:2018, 3.284]

3.59

sterilizer

equipment designed to achieve sterilization (3.56)

[SOURCE: EN ISO 11139:2018, 3.287]

3.60

sterilizing agent

physical or chemical entity, or combination of entities, having sufficient microbicidal activity to achieve sterility under defined conditions

[SOURCE: EN ISO 11139:2018, 3.288]

3.61

type test

technical operation to verify conformity of an equipment type to a standard or specification, and to establish (3.15) data for reference in subsequent tests

[SOURCE: EN ISO 11139:2018, 3.306]

3.62

unloading door

means through which a load (3.30) is removed from the chamber (3.6) after processing

[SOURCE: EN ISO 11139:2018, 3.310]

3.63

validation

confirmation process, through the provision of objective evidence, that the requirements for a specific intended use or application have been fulfilled

Note 1 to entry: The objective evidence needed for a validation is the result of a test or other form of determination such as performing alternative calculations or reviewing documents.

Note 2 to entry: The word “validated” is used to designate the corresponding status.

Note 3 to entry: The use conditions for validation can be real or simulated.

[SOURCE: EN ISO 11139:2018, 3.313]

3.64

verification

confirmation, through the provision of objective evidence, that the specified requirements have been fulfilled

Note 1 to entry: The objective evidence needed for a verification can be the result of an inspection (3.25) or of other forms of determination such as performing alternative calculations or reviewing documents.

Note 2 to entry: The word “verified” is used to designate the corresponding status.

[SOURCE: EN ISO 11139:2018, 3.314]

3.65

works test

series of technical operations performed prior to delivery to demonstrate compliance of a piece of equipment with its specification

[SOURCE: EN ISO 11139:2018, 3.325]

4.0 General

4.1 Sterilizer type

4.1.1 A sterilizer type establishes when the design of a sterilizer does not require tests to be repeated when design variations are made.

NOTE For the same sterilizer type, design variations that do not influence performance can be exempted from retesting.

A risk evaluation shall demonstrate that design variations within a given type do not affect sterilizer performance.

Conformance is demonstrated by inspection (see 10.1.4).

4.1.2 When demonstrating that a type of a VH2O2 sterilizer conforms with this document, sterilizers within the same type shall:

a) have the same intended use, and;

b) have the same sterilant and sterilizing agent;

In addition, unless it has been demonstrated that there is no decrease in the performance of an operating cycle, a sterilizer type shall have:

c) the same number of doors in the same configuration;

d) all service connections into the chamber in the same orientation;

e) the same control system with all sensors located in the same position and orientation;

NOTE Where a change within the control system does not affect the sequence of stages of the sterilization cycle, the cycle parameters, or the safety attributes, such a change does not constitute a new type.

Conformance is demonstrated by inspection (see 10.1.4).

4.1.3 If all other design aspects remain the same, the following variations shall not constitute a new type:

a) a mirror image of the original orientation;

b) height of the chamber above the floor;

c) differences in the dimensions of the chamber and chamber volume not greater than ± 10 %;

NOTE Additional requirements can apply to cycle changes. While not a new sterilizer type, this is a new sterilization cycle (see ISO 22441:2022, 10.3.3.3).

Conformance is demonstrated by inspection (see 10.1.4).

4.1.1 Sterilizer development

4.2.1 The design and development process is a critical element in product realization of a sterilizer. To ensure the consistent implementation of the requirements specified in this document, the necessary development processes shall be established, implemented, and maintained. Processes of particular importance in relation to the design and development of a sterilizer include but are not limited to:

— risk management;

— control of documentation, including records;

— assignment of responsibility;

— provision of adequate resources, including competent human resources and infrastructure;

— control of product, including services, provided by external parties;

— calibration of instrumentation.

NOTE 1 EN ISO 13485 covers all stages of the lifecycle of medical devices in the context of quality management systems for regulatory purposes. National or regional regulatory requirements for the provision of health care product can require the implementation of a full quality management system and the assessment of that system by a recognized conformity assessment body.

NOTE 2 EN ISO 14971:2019 provides further information for a risk management system for medical devices.

NOTE 3 EN ISO 12100:2010 provides further information for risk management of machinery.

4.2.2 Where a new sterilization cycle is being developed for implementation into a sterilizer, an update of the risk analysis shall be performed to ensure that any additional potential risk is considered for the design.

Conformance for 4.2 is demonstrated by inspection (see 10.1.4).

4.1.2 Calibration

4.3.1 Instrumentation on the sterilizer and instruments used for test purposes shall be calibrated.

4.3.2 The system(s) for calibration of instrumentation shall provide metrological traceability to a primary standard or national standard with a known level of measurement uncertainty.

4.3.3 Means shall be provided to permit connection of reference instruments for the calibration of instrumentation.

Conformance for 4.3 is demonstrated by inspection (see 10.1.4).

5.0 Sterilizer design and Construction

5.1 Safety and security

5.1.1 General

5.1.1.1 The safety of the design shall be based on risk assessment in accordance with 5.1.3.1.

NOTE 1 For general design related to safety, see EN IEC 61010‑2‑040:2021.

NOTE 2 Additional guidance is given in EN ISO 12100:2010.

Conformance is demonstrated by inspection (see 10.1.4).

5.1.1.2 Sterilizers shall incorporate means of protection from unauthorized access that could interfere with its performance or create a hazardous situation.

5.1.1.3 If the sterilizer provides a connection to an IT environment or network, means shall be provided to prevent access or interaction:

a) between that environment or network and the sterilizer that interferes with the sterilizer performance or creates a hazardous situation;

b) between the sterilizer and that environment or network protocol(s) that interferes with the specified performance of the environment or network.

NOTE See EN IEC 80001‑1, EN ISO/IEC 27001, EN ISO/IEC 27002, UL 2900‑1 and ISO/IEC 21823‑1.

Conformance to 5.1.1 is demonstrated by inspection (see 10.1.4).

5.1.2 Protective measures

General

Protective measures for the design of the sterilizer should consider the state of the art and applicable standards according to 5.1.2.2.

NOTE The type of sterilizer (see 4.1) and its application, the application range (e.g. health care, industrial), and the respective risk classification (see e.g. 5.1.3), different European Directives or national regulations and related harmonized standards can apply.

Conformance is demonstrated by inspection (see 10.1.4).

Specific requirements

With regard to the specific protective measures defined below, the sterilizer shall, besides respective requirements specified elsewhere in this document, comply with the requirements specified in the indicated references to EN IEC 61010‑2‑040:2021 when tested according to the test methods provided for this purpose. In addition, further related references are provided for information in Annex G and should be taken into account as far as applicable:

a) For marking and documentation, sterilizers shall comply with EN IEC 61010‑2‑040:2021, 5.1. and 5.2. See also 11.4.

b) For the protection against electric shock, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clause 4 and 6.

c) For the protection against mechanical hazards and hazards related to mechanical functions, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clause 4 and Clause 7.

d) For the protection against hazards due to mechanical resistance to shock and impact, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clauses 4 (except 4.4) and 8.

e) For the protection against the spread of fire, sterilizers shall comply with, EN IEC 61010‑2‑040:2021, Clause 9 (except 9.5).

f) For the protection against hazards in relation to temperature and to heat, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clause 10.

g) For the protection against hazards from fluids, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clause 11.

h) For the protection against liberated gases, substances, explosion and implosion, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clause 13.

i) For the protection against hazards related to components, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clause 14.

j) for the protection against hazards resulting from failures of software for software-controlled devices related to safety of sterilizer operation or process control: EN IEC 61010‑2‑040:2021, 14.104.

NOTE Safety related software is addressed in 6.2.5 and 6.2.6.

k) For the protection by interlocks, sterilizers shall comply with EN IEC 61010‑2‑040:2021, Clause 15.

Conformance of the sterilizer with the stated requirements is demonstrated by application of related test procedures provided by the references.

5.1.2.3 If a powered chamber door is fitted, systems shall be provided to permit the removal of persons or objects entrapped by the moving door before the pressure, force and temperature specified in EN 61010‑1:2010, 7.3.4 and 10.1 are exceeded.

NOTE Reversing the direction of the door movement is a way to achieve this.

Conformance is demonstrated by inspection and inspection of the technical documentation.

5.1.2.4 Sterilizers shall conform with EN IEC 61326‑1:2021, Clause 6, regarding immunity to electromagnetic interference.

The immunity performance criteria selected shall ensure that sterilizer performance is met when exposed to the applicable disturbance phenomena of EN IEC 61326‑1:2021, 10.1.

Conformance is demonstrated in accordance with EN IEC 61326‑1:2021, Table 1, Table 2 or Table 3, as applicable.

NOTE Further information regarding electromagnetic emissions is provided in 8.1 of this document.

5.1.3 Risk control and usability

5.1.3.1 Risk assessment and risk control for sterilizer design and software shall be performed following the procedures and requirements given in EN ISO 14971:2019, Clause 5, Clause 6 and Clause 7. Specific requirements and results shall be established and documented.

5.1.3.2 Risk analysis shall address the specific sterilizer design and features. Measures taken for risk reduction shall consider aspects as user knowledge, experience, training, ergonomics and usability.

Conformance to 5.1.3 is demonstrated by inspection (see 10.1.4).

NOTE EN ISO 12100:2010 or EN 61508‑1 provide further information.

5.1.3.3 Known or foreseeable hazards and hazardous situations related to usability shall be assessed in accordance with EN IEC 62366‑1:2015.

5.2 Chamber

5.2.1 Materials

5.2.1.1 The materials of construction of the sterilizer in contact with the sterilant and/or sterilizing agent shall not react or cause material deterioration in accordance with EN IEC 61010‑2-040:2021, 13.1.103.4 and 13.2.101.

NOTE If impaired by chemicals (sterilant and/or sterilizing agent), chamber walls, connected piping and welds could possibly react with these chemicals and release substances known to be toxic in such quantities that it can create a health or environmental hazard.

5.2.1.2 Materials for sterilizers accessories including load supporting systems shall be selected to avoid corrosion including galvanic effects.

Conformance for 5.2.1 is demonstrated by inspection (see 10.1.4).

5.2.2 Chamber dimensions

Chamber

For the internal dimensions of the chamber the following dimensions shall be specified in millimetres, as applicable:

a) for cylindrical internal chamber dimensions: 000 × 000 in which:

1. the first three digits give the diameter of the internal chamber dimensions; and

2. the last three digits give the depth of the internal chamber dimensions;

b) for rectangular parallelepiped internal chamber dimensions: 000 × 000 × 000 in which:

1. the first three digits give the width of the internal chamber dimensions;

2. the next three digits give the height of the internal chamber dimensions; and

3. the final three digits give the depth of the internal chamber dimensions;

c) if any dimension exceeds 999 mm, then four digits shall be used, without a decimal point.

NOTE For configurations that are not cylindrical or rectangular, the internal chamber dimensions can be specified in analogy to a) or b).

Usable Chamber space

For the usable chamber space, the following dimensions shall be specified in millimetres, as applicable:

a) for cylindrical horizontal or cylindrical vertical usable chamber spaces: 000 × 000 in which:

1. the first three digits give the diameter of the usable chamber space; and

2. the last three digits give the depth of the usable chamber space;

b) for rectangular parallelepiped usable chamber spaces: 000 × 000 × 000 in which:

1. the first three digits give the width of the usable chamber space;

2. the next three digits give the height of the usable chamber space; and

3. the final three digits give the depth of the usable chamber space;

c) for other configurations the usable chamber space shall be specified in analogy to a) or b);

d) if any dimension exceeds 999 mm, then four digits shall be used, without a decimal point.

Conformance for 5.2.2 is demonstrated by inspection (see 10.1.4).

5.2.3 Doors and interlocks of the chamber

5.2.3.1 Chambers shall be provided with one or two doors.

5.2.3.2 Sterilizers shall be equipped with an interlock so that, under conditions of normal operation, the pressure in the chamber cannot be increased or decreased and sterilizing agent cannot enter or escape from the chamber when the door is unlocked or unsealed.

5.2.3.3 After closing the door, it shall be possible to open it before a cycle has been started.

5.2.3.4 It shall not be possible to open a door(s) during a cycle.

5.2.3.5 In case of an interrupted cycle (e.g. due to a fault), opening of the door shall require the use of an access device and conditions that will not create a hazard (e.g. residue of sterilizing agent).

5.2.3.6 The design shall allow maintenance of the door seal(s) in accordance with the user instructions.

5.2.3.7 Once a sterilization cycle is initiated for routine operation it shall not be possible to open the unloading door until a cycle complete indication is obtained.

5.2.3.8 For operating cycles dedicated for test or user maintenance purposes only, the indication of the cycle being completed shall be different from the cycle complete indication of a routine sterilization cycle.

5.2.3.9 If a fault is indicated, or on completion of an operating cycle for test or sterilizer maintenance purposes, it shall not be possible to open a door until appropriate action is taken.

5.2.3.10 Except for maintenance purposes, it shall not be possible on double-ended sterilizers to open both sterilizer doors at the same time.

5.2.3.11 For double-ended sterilizers, both ends of the sterilizer shall be fitted with a device to indicate whether the door at that end can be opened.

5.2.3.12 For double-ended sterilizers, cycle complete shall be cancelled if the unloading door is opened.

5.2.3.13 For double-ended sterilizers the loading door shall remain locked until the unloading door has been opened, closed, and locked again.

Conformance for 5.2.3 is demonstrated by inspection (see 10.1.4).

5.2.4 Temperature control and insulation

5.2.4.1 Initiation of a sterilization cycle shall not be possible until the chamber inner surfaces (including doors) have reached a pre-set temperature range in accordance with D.2.1.

5.2.4.2 Sterilizer chamber inner surfaces shall be temperature controlled within a specified range during sterilization cycles in accordance with D.2.1.

5.2.4.3 Where hot surfaces can cause a burn hazard and to reduce heat transmission to the environment, these surfaces shall be insulated, except where this will interfere with the intended function of the sterilizer.

Conformance for 5.2.4 is demonstrated by inspection (see 10.1.4).

5.2.5 Test connections

5.2.5.1 The chamber shall be provided with at least one test connection, which is used for the connection of test measuring instruments. This connection shall be at a point of easy access, but not restricting a pipe for fluid transport or evacuation, and shall terminate in a flange connection in accordance with ISO 2861:2020. The test connection(s) shall be connected to the chamber with a size of DN16 KF or larger.

5.2.5.2 The test connection shall be sealed with a suitable seal.

Conformance for 5.2.5 is demonstrated by inspection (see 10.1.4).

5.3 Further functional components

5.3.1 Pipework and fittings

5.3.1.1 In pipework used for services, means shall be provided to prevent the ingress of contaminants from external sources that could affect the performance of the sterilizer.

NOTE For connections to a potable water supply and to drainage, national or local regulations can apply.

5.3.1.2 Pipework shall be designed to prevent unintended accumulation of condensate.

NOTE 1 Accumulation of H₂O₂ can create a hazard.

NOTE 2 Insulation can be applied to reduce the formation of condensate. Insulation cannot be applied when it interferes with the function of the sterilizer.

5.3.1.3 All control valves in the pipework and test connections shall be marked with permanent identification.

Conformance for 5.3.1 is demonstrated by inspection (see 10.1.4).

5.3.2 H2O2 vaporizer

5.3.2.1 If a vaporizer, which may be part of the chamber, can be disconnected from the feed to the chamber, means shall be provided to give protection from accidental hazardous effluent to the environment in accordance with EN IEC 61010‑2‑040:2021, 11.101 and 13.1.

5.3.2.2 Means shall be provided to prevent any excessive temperature which can create hazards, e.g. fire or explosion.

5.3.3 Evacuation system

5.3.3.1 Sterilizers shall be provided with a vacuum system to remove air, humidity, and H₂O₂ to the lowest pressure needed to fulfil the requirements of 6.7, 10.1, 10.2 and Annex D.

5.3.3.2 The vacuum system shall reduce the H₂O₂ concentration and its possible reaction products to concentrations below that considered harmless to the operator and the environment (see 8.3.2).

5.3.3.3 The sterilizer shall be provided with means for leak testing which shall include the chamber and all relevant connected pipework and fittings. During leak testing, the chamber and relevant pipework shall be subjected to a pressure below ambient at or below the lowest set-point applied during the cycle(s) available to the operator, in accordance with 6.2.2. If a leakage from the vaporizer can cause a hazard, the vaporizer shall be included in the leak testing or a separate test procedure for leak testing shall be provided.

Conformance for 5.3.3 is demonstrated by inspection (see 10.1.4).

5.4 Framework and panelling

5.4.1 If the sides of the sterilizer do not need to be accessible for normal operation, they shall be enclosed with panelling.

NOTE 1 Side panelling is not required for sterilizers designed to be recessed into existing walls providing continuous joints with the sterilizer front panelling.

NOTE 2 Ventilation openings can be provided in the panelling.

5.4.2 Removal or opening of panels used as a physical barrier to provide protection (guard) shall require the use of an access device.

5.4.3 The panelling shall be corrosion-resistant to recommended cleaning and disinfection agents and specified working environment conditions [see 11.4.2 and 11.5.1 k)].

5.4.4 The panelling of the sterilizer shall allow access for maintenance work. Such panelling shall be demountable, or the dimensions of any personnel access shall not be less than 500 mm wide and not less than 1 500 mm high.

5.4.5 Fixings for these panels shall remain attached to either the panels or to the body of the sterilizer when panels are removed.

5.4.6 The access for maintenance shall be positioned so that it will not compromise the safety of either the product or persons.

NOTE Further information for access is also specified in EN IEC 61010‑2‑040:2021, Clause 7.3 and 7.109.

5.4.7 The sterilizer shall be designed to operate when installed on a surface which is horizontal within the tolerance limits specified in Tables 1 and 2 and which will support the maximum floor loading.

The floor should be impervious to water and collect or drain water spillage from the sterilizer.

Table 1 — Tolerance for the aperture into which the sterilizer is installed

Aperture dimension m	Tolerance mm
	Horizontal plane	Vertical plane
up to 3	±12	±16
above 3 to 6	±16	±16
above 6 to 15	±24	±20
above 15 to 30	±24	±20
above 30	±30	±30
SOURCE: EN 285:2015+A1:2021

Table 2 — Deviation from vertical and horizontal flatness and alignment

Distance between any two measuring points m	Deviation mm
	Finished surfaces of walls and ceilings	Finished floor (bearing surface)
0,1	3	2
1	5	4
4	10	10
10	20	12
15	25	15
SOURCE: EN 285:2015+A1:2021

Conformance for 5.4 is demonstrated by inspection (see 10.1.4).

5.4.1 Vibration

5.5.1 Vibrations from sterilizers shall be reduced by design and selection of components that limit vibrations, particularly at source.

5.5.2 If vibrations can cause a loss of stability of the sterilizer, means shall be provided for suitable fixation.

NOTE Guidance to reduce vibration at source is provided in EN ISO 12100:2010, 6.2.2.2, 6.2.3, 6.2.6, and 6.3.4.3.

Conformance for 5.5 is demonstrated by inspection (see 10.1.4).

5.4.2 Ancillary equipment and components

5.6.1 If loading equipment is provided it shall be assessed from a usability point of view.

NOTE EN IEC 61010‑2‑040:2021, 7.5.101 provides additional information on load transfer into and out of the chamber.

5.6.2 Specified dedicated accessories intended to be used with or connected to the sterilizer shall not cause any hazard or detrimental effect to the performance of the sterilizer.

5.6.3 The mutual compatibility of the ancillary equipment with the sterilizer shall be verified.

Conformance for 5.6 is demonstrated by inspection (see 10.1.4).

5.4.3 Transport

5.7.1 Where the weight, size, or shape of the sterilizer, or its various component parts, prevents them from being moved by hand, the sterilizer, or each component part shall either be fitted with attachments for lifting gear, or be designed so that it can be fitted with such attachments, or be shaped in such a way that standard lifting gear can easily be attached.

NOTE EN 61010‑1:2010, 7.5 provides information for lifting and carrying the equipment.

5.7.2 The sterilizer, its components and dedicated consumables (if applicable) shall be packed for transportation and storage in a way that their performance characteristics are maintained and no moving part can cause a hazard.

Conformance for 5.7 is demonstrated by inspection (see 10.1.4).

5.4.4 User interfaces

5.8.1 The control used to start the automatic operating cycle shall be located at the loading side of the sterilizer or in a remote operating facility.

5.8.2 If a remote operating facility is used, a risk analysis shall be performed to ensure safe operation and service of the sterilizer and the safety of the installation area.

5.8.3 Sterilizers shall be provided with the indicating devices specified in 6.6.

5.8.4 Where a sterilizer is operated remotely, the indicating devices specified in 6.6 shall be provided at the remote location.

5.8.5 Means shall be provided for the user to terminate the operating cycle without causing a hazardous situation. If a fault results in aborting or terminating an operating cycle in progress, the visual indication of the fault shall continue until the user completes a specified action to clear the indication of the fault.

5.8.6 Means shall be provided to permit operation of the sterilizer for maintenance, test purposes and in cases of emergency, without causing a hazardous situation. A service mode shall be activated by use of an access device and shall be clearly indicated in order to avoid safety features being inactivated during normal operations.

5.8.7 Indicating, measuring, and recording instruments shall be identified as to their function. Instruments and indicating devices shall be located where they can be viewed readily by the user under standard operation of the sterilizer. Instruments and gauges shall be readable by normal or corrected vision from a distance of 1 m and with a minimum illumination of (215 ± 15) lx.

5.8.8 If an instrument on the sterilizer is adjustable, the adjustment shall require the use of an access device.

5.8.9 When fitted, acoustic signals not associated with a hazardous situation shall be time-limited to 30 s or it shall be possible to interrupt them.

Conformance for 5.8 is demonstrated by inspection (see 10.1.4).

6.0 Indicating, monitoring, controlling, and recording devices

6.1 General

The sterilizer comprised an automatic controller with pre-set programmes and cycle(s) (see 6.2). The controller is part of a control and monitoring system (see 6.3) that allows detection of failure (see 6.4) and comprises instrumentation, indicating devices and recorder sub-units (see 6.5, 6.6 and 6.7).

6.1.1 Automatic control

6.2.1 The sterilizer shall be operated by an automatic controller with permanently stored pre-set programmes and one or more operating cycle.

Means shall be provided to ensure that a failure in a control function does not lead to a failure in recording of process and cycle variables such that an ineffective process appears effective. This may be achieved either by the use of independent systems for control and recording, or by a cross-check between control and recording that identifies any deviations of process or cycle parameters outside their specified measurement tolerances and indicates a fault.

NOTE 1 Examples of concepts for control and monitoring systems and the interrelationship between control and recording are discussed and illustrated in Annex I.

NOTE 2 A VH2O2-sterilizer can provide one or more sterilization cycles to consider specific performance requirements and/or challenges of different types of load or load configurations (see 11.2) in order to adjust, for example, to the load capacity (small load, full load, reduced load), to take into account the composition of small individual items vs single complex instruments like endoscopes or to propose specific requirements for desorption etc.

NOTE 3 Automatic loading and unloading can be carried out before the start and after the end of an operating cycle.

6.2.2 The parameters of the operating cycle for controlling, monitoring, recording, and indication shall be established and specified.

Conformance is demonstrated by inspection of the technical documentation and by successful type tests according to Annex A.

6.2.3 Upon selection of a specific sterilization cycle for operation and before start, the intended use and designation of this cycle shall be clearly indicated.

Figure 1 shows an example of a VH2O2-sterilization cycle demonstrating relations of cycle stages.

NOTE The sterilizer and associated equipment is used only for the sterilization of the type of products for which it is designed. The choice of the sterilization cycle provided can be inappropriate for a particular load. Therefore, the suitability of a sterilization process for a product intended to be sterilized can be verified by validation, see ISO 22441:2022.

6.2.4 In course of operating cycles used for production, leak monitoring shall be performed. During selected operating stage(s) an unintended pressure rise exceeding specified limit values shall activate a visual and/or audible fault indication. The operating cycle shall be interrupted automatically and terminated immediately following the applicable procedures specified in 6.4.2.

6.2.5 For maintenance or testing purpose an automatic test cycle shall be provided to carry out the air leakage test in accordance with D.2.8 and display the rate of pressure rise caused by air leakage. The pressure change measured shall be ≤ 20 Pa per minute when tested over a period of 10 min.

6.2.6 The sterilization cycle(s) shall include a purging stage in accordance with 8.3 and EN IEC 61010‑2‑040:2021, Clause 13.

6.2.7 The automatic controller shall be protected against short circuit in components or equipment, which are directly or indirectly connected to the controller.

6.2.8 The automatic controller shall have status indicators for each digital input and output.

NOTE This can be located within the control cabinet.

6.2.9 The automatic controller shall be located such that the maximum and minimum values of temperature, humidity and pressure specified for the automatic controller are not exceeded.

Conformance is demonstrated by inspection of the technical documentation.

6.2.10 The automatic controller shall not cause a hazardous situation, if:

a) the values of cycle parameters are outside the specified limits;

b) a power failure occurs;

c) a failure of another utility occurs.

NOTE EN 61511 series can provide additional specifications for safety instrumented systems for the process industry sector.

6.2.11 The pre-set programmes of the automatic controller shall allow reproducible control, indication, monitoring and recording of the operating cycle to ensure that the pre-set programmes perform as intended. For more information see Annex A.

6.2.12 Software for automatic controller’s function as intended. The safety consequences of software shall be established through risk assessment (see 5.1.3.1).

NOTE Software safety classification is considered in EN 62304.

6.2.13 Safety related software, including software for monitoring, control, and recorders shall be verified and validated according to its classification (see e.g. EN 62304). The methods used in the verification and validation processes shall be selected based on the intended purpose of the software.

NOTE Regarding software information see, for example, EN 61508 series, EN 62304 and EN IEC 62061.

6.2.14 Means shall be provided so that if a failure of the automatic controller occurs, the sterilizer shall be brought to a condition that presents no hazard to the operator, any ancillary equipment, or the operating environment. Opening of the chamber door(s) shall not cause a hazardous situation and shall require the use of an access device (see also 5.2.3.4).

6.2.15 For sensors for indicating or recording purposes, means shall be provided to indicate a sensor failure.

6.2.16 When a sensor is used for a control function, it shall have broken sensor indication.

6.2.17 Programming the automatic controller and any change of the pre-set programme or its parameters shall require the use of an access device.

6.2.18 It shall not be possible to adjust any process or cycle parameter during the progress of an operating cycle.

6.2.19 Access to any automatic controller function shall only be possible by use of an access device.

6.2.20 For maintenance, test purposes, failure analysis and in cases of emergency, means shall be provided to permit manually controlled progression of the automatic controller using an access device.

Conformance for 6.2 is demonstrated by inspection (see 10.1.4).

6.1.2 Control and monitoring system

6.3.1 The control and monitoring system typically comprises different subunits (for computing, measuring chains, instrumentation) and directs operation of the sterilizer using software modules for data collection and processing, cycle control, cycle parameter and status indications, operating controls, independent recording and data storage, process evaluation, and fault indication.

6.3.2 The control and monitoring system shall have separate measuring chains for the measurement of control data and independent data for the monitoring system (see also 6.5 and 6.7). Independent measurement systems with separate measurement chains by cycle control and recording shall be applied to defined cycle variables and process variables. Separate analogue to digital converters shall be used for the control data and independent data. Risk analysis identifies which cycle variables or process variables require redundant supervision.

NOTE Examples of concepts for control and monitoring systems and the interrelationship between control and recording are discussed and illustrated in Annex I.

6.3.3 The control and monitoring system shall have segregated software modules that process the control data and the independent data independently of each other.

6.3.4 The control data shall be provided to the control function from the data processing system and the control measurement chain.

6.3.5 The independent data shall be provided as a one-way flow to data retention.

NOTE This does not exclude the transfer of informative data between the control function and failure detection, and data retention, via a combined system for data transfer.

6.3.6 The control and monitoring system shall include means for failure detection. This shall receive both processed control data and independent data and shall indicate a failure if the control data and independent data differ from specified conditions.

6.3.7 The independent data and the control data shall be stored in a data retention module, along with notification of failures. These data shall be transferred to a recording system in accordance with 6.7 (see also Annex I).

6.3.8 A printer may be provided as an option.

NOTE If the optional printer is provided it can be either built in or be connected as an external device. For details see 6.7.

Conformance for 6.3 is demonstrated by inspection (see 10.1.4).

6.1.3 Failure

6.1.4 General

6.4.1.1 Failure of items and parameters identified by risk analysis to be critical to process or safety, including the services, shall be detected by the monitoring system of the sterilizer.

NOTE 1 A failure can require different types of indications depending upon its potential effects and urgency, for example, audible/visual alarms, warnings, error indications, messages, displays, as well as subsequent automated responses of sterilizer or correction by the operator.

NOTE 2 The consequences of a failure can depend on the current operation mode of the sterilizer. Different levels for alarms and indications depending on the related criticality could be provided.

EXAMPLE A depletion of the sterilant supply during the conditioning stage of an operating cycle results in an alarm and an abort of the operating cycle. On the other hand, the same failure during the desorption/drying stage does not necessarily affect the successful completion of the operating cycle, but only causes a warning message and prevents the start of a next operating cycle.

6.4.1.2 Such failure of items and parameters critical to process or safety detected by the monitoring system of the sterilizer shall be indicated and explained in the instructions for use regarding the activation conditions, the intended or potential consequences and the required correction.

6.4.1.3 Interpretation and implications for consequences shall be based on risk analysis and risk assessment in accordance with 5.1.3.

6.1.5 Fault

6.4.2.1 If a failure addressed by 6.4.1.1 causes one or more of the process or cycle parameters to be outside its/their specified tolerances during an operating cycle, or if an operating cycle is interrupted by the operator, a fault shall be indicated and shall cause an audible or visual alarm.

NOTE Not every failure will result in a fault (see 3.19).

6.4.2.2 If the operating cycle has been completed in accordance with the programme and no fault has occurred, cycle complete shall be generated. After a fault, cycle complete shall not be generated.

6.4.2.3 If a fault occurs prior to or during the sterilization phase, the load is considered non-sterile and the control shall ensure that for single door sterilizers the door, or for double ended sterilizers, the unloading door, cannot be opened.

6.4.2.4 If a fault is indicated, the automatic controller shall:

a) prevent continuation of the normal sequence of process stages;

b) indicate the fault and the operating cycle stage at which the fault occurred;

c) record the fault message and the operating cycle stage at which the fault occurred.

6.4.2.5 The visual display indicating that a fault has occurred shall continue at least until the release of the loading door locking mechanism. Any fault indication shall be distinguishable from the indication of a satisfactory sterilization cycle.

6.4.2.6 After a fault has been indicated, the automatic controller shall either:

a) initiate automatic progress to a desorption stage (see 8.3) if hydrogen peroxide has already been admitted to the chamber, followed by stages for recovery of the system which, when completed, allows the loading door to be opened without creating a hazardous situation, with no indication of cycle complete, or

b) initiate automatic progression of stages of the operating cycle to a safe condition, at which there shall be no indication of cycle complete, or

c) by use of an access device, allow manual progression by an authorized person through the cycle to a safe condition with no indication of cycle complete.

6.4.2.7 After completion of the measures addressed in 6.4.2.6, access to the sterilizer load shall require the use of an access device, and the load shall be considered nonsterile.

NOTE Additional guidance regarding faults and safety can be found in EN IEC 61010‑2‑040:2021.

6.1.6 Power failure

In the event of a power failure which causes a fault, 6.4.2 shall apply after restoration of the power.

6.1.7 Other failures

6.4.4.1 If a failure of the sterilizer, the current operating cycle, or any service does not create a fault, its indication shall be distinguishable from a fault indication.

6.4.4.2 If a failure can create a fault at a later stage of an operating cycle, or after initiation of another operating cycle, a respective warning shall be displayed.

6.4.4.3 If a failure can create a hazardous situation, the controller, in combination with other safety systems, shall automatically initiate action to prevent a hazardous situation. The failure shall be indicated by an audible and visible alarm. The alarm indication shall allow the operator to identify the failure and shall provide a directive by text or by reference to an instruction manual for correction. The failure indication shall be recorded in order to allow retrospective identification and analysis.

6.4.4.4 Any other failure may be displayed as a message as appropriate.

Conformance for 6.4 is demonstrated by inspection (see 10.1.4).

6.2 Instrumentation

6.2.1 General

6.5.1.1 The sterilizer shall be provided with instruments to measure and control the cycle variables.

6.5.1.2 In order to achieve reproducible sterilization cycles, in VH2O2 the following cycle variables shall be considered for control, monitoring, indication and recording, but are not limited to:

a) temperature (see 6.5.2, 6.6.4.3.);

b) pressure (see 6.5.3, 6.6.4.4);

c) sterilizing agent concentration and/or sterilant composition and amount supplied to the process (see 6.5.5, 6.6.4.2);

NOTE 1 E.g. volume, dose, mass flow, concentration, partial pressures can be used as appropriate.

d) time (see 6.5.4, 6.6.4.1).

NOTE 2 Residual moisture on product surfaces (e.g. due to deficient drying after washing) can affect the process efficacy.

6.5.1.3 Instruments shall cover the scale range applicable to the operating cycle(s). Instruments shall have specified accuracy or maximal permissible errors sufficient for the automatic control to detect and respond to deviations from the tolerance of the cycle parameters.

6.5.1.4 The measuring chain response time and hysteresis used for indicating, measuring, and recording devices shall be appropriate to monitor and represent the sterilization process. The data and sampling interval of sensors and measuring chains for indicating devices shall be not more than 1 s.

6.5.1.5 Any adjustment to the instrumentation shall not be possible during routine operation of a cycle.

6.5.1.6 If an indicating instrument is connected in turn to more than one sensing point, there shall be a continuous indication of the active sensor that is being monitored.

6.2.2 Temperature measuring devices

Temperature parameters

Sterilizers shall be provided with instrumentation that provides the following parameters:

a) sterilizer chamber temperature for indication;

b) sterilizer chamber temperature for control;

c) sterilizer chamber temperature for independent data collection and recording;

d) sterilizer chamber wall temperature for control (see 5.2.4).

Instrumentation for a) and b) may be combined.

Temperature sensor

6.5.2.2.1 Temperature sensors used for control, independent data collection and indication shall comply with the requirements on measurement error for the complete measurement chain stated in 6.5.2.3.2. A dual element temperature probe may be used.

NOTE EN IEC 60751:2022 and EN 60584‑1:2013 specify tolerance classes for different type of temperature sensors.

6.5.2.2.2 The sensors used for indication, control, and independent data collection of the temperature of the sterilization cycle shall be located at the point identified as the reference measurement point.

NOTE For information on the temperature reference measuring point see 10.2.1.

Temperature measuring chains

6.5.2.3.1 At least two temperature measuring chains shall be provided to cover control, independent data collection, and indication, one of which is independent from the temperature measuring chain(s) for control.

6.5.2.3.2 The temperature measuring chains shall:

a) have a measurement error not exceeding 1 K over the scale range 20 °C to 60 °C; within the operating ambient temperature range specified for the sterilizer;

b) ensure a measurement error not exceeding 0,5 K at the specified sterilization temperatures.

6.2.3 Pressure measuring devices

Pressure parameters

Sterilizers shall be provided with instrumentation that provides the following parameters and their display shall be identified:

a) absolute pressure in the chamber for indication. For double-ended sterilizers, this indication shall be provided at each end;

b) absolute pressure in the chamber for control;

c) absolute pressure in the chamber for independent data collection and recording.

Instrumentation for a) and b) may be combined.

Pressure measuring chains

6.5.3.2.1 Pressure transducers and measuring chains for control, independent data collection, and indication shall provide absolute pressure data.

6.5.3.2.2 At least two pressure measuring chains shall be provided to cover control, independent data collection, and indication, one of which is independent from the pressure measuring chain(s) for control.

6.5.3.2.3 The pressure measuring chains shall:

a) provide a measurement range from 0,5 times of the minimum operating pressure up to 100 kPa absolute;

b) have a measurement error of the whole measuring chain, after adjustment, at the operating temperature, not exceeding 10 % of the actual value, over the range up to 100 kPa as specified for the sterilant injection stage of the cycle;

c) be calibrated at following operating pressures:

1. lowest vacuum switch point;

2. maximum operating pressure(s) during cycle stage(s);

3. defined level within ± 10 % of standard ambient pressure (101,3 kPa).

d) have a maximum measurement error at these points that shall be smaller than the tolerances established for the operating cycle parameters;

e) have a measurement error caused by an environmental temperature change not exceeding 0,1 %/K over the measurement range 10 Pa to 100 kPa;

f) if used for air leakage test, have an error in measurement for a pressure difference starting at the lowest pressure applied during the entire process that shall not exceed 10 % over the pressure range that may occur during the test.

NOTE Due to the range of pressure in the process, it can be necessary to have more than one pressure sensor.

6.2.4 Time measuring devices

6.5.4.1 Time measuring devices (timers) shall be provided to cover control, monitoring, and recording of the operating cycle steps.

NOTE Timers are typically part of automatic controllers (external) recorders and printers (see 6.7).

6.5.4.2 Time periods shall have a measurement error not exceeding 1 s.

6.2.5 Sterilizing agent control and measuring devices

6.5.5.1 The sterilizer shall be equipped with a system for control and monitoring directly or indirectly the VH2O2 concentration during the process. This system shall be such that failure of a single component or the concentration being outside of the defined tolerances shall result in a fault indication.

NOTE 1 Control of VH2O2 supplied to the evacuated chamber and the load can, for example, be performed:

a) by a knowledge of Sterilant concentration in H₂O₂ and measurement of the amount of sterilant used (mass, volume, dose, flow) and the resulting pressure change in the chamber (sum of partial pressures of the components of the specified sterilant composition) under consideration of the temperature and possible consumption by chemical reactions or by adsorption/absorption/condensation on chamber walls and the load,

b) by measurement of the concentrations of the components of the sterilizing agent using suitable measurement principles and equipment.

NOTE 2 Information about measurement of hydrogen peroxide for monitoring and control is provided in Annex E.

6.5.5.2 The error in measurement of the monitoring system shall be less than 10 % of the values specified for the cycle (see 10.1.7).

Conformance for 6.5 is demonstrated by inspection (see 10.1.4).

6.3 Indicating devices

6.3.1 General requirements

For general requirements on indications see 5.8, 6.4 and 6.5.

6.3.2 Status indicators and indication

6.6.2.1 The sterilizers shall be fitted with status indicators displaying:

a) status of the services necessary to operate the operating cycle safety;

b) visual display indicating sterilizer door locked;

c) the operating cycle selected, if applicable;

d) cycle in progress;

e) operating cycle stage;

f) operating cycle complete;

g) fault (see 6.4.2);

h) when the sterilizer door can be opened (see 5.2.3.9).

6.6.2.2 Double ended sterilizers having separate doors for loading and unloading in separate areas shall be fitted with status indicators displaying on both ends of the sterilizer:

a) sterilizer doors locked;

b) cycle in progress;

c) cycle complete;

d) fault (see 6.4.2);

e) when the sterilizer door can be opened (see 5.2.3.10).

6.6.2.3 Symbols may be used to provide a status indication. These symbols shall be provided in the instructions for use.

6.6.2.4 If a test operating cycle is provided, an indication at the end of the test operating cycle shall be different from a sterilization cycle.

6.3.3 Operating cycle counter

A counter shall be provided to indicate the cumulative number of all operating cycles started, including those cycles in which a fault occurred. The cycle counter shall display a minimum of four digits and shall only be capable of being reset by a person authorized to do so by means of an access device.

6.3.4 Cycle parameters indicating device

Time indicating devices

6.6.4.1.1 Times and time periods information shall be provided using hours, minutes, and seconds, indicated as hh:mm:ss as applicable.

6.6.4.1.2 Dates shall be graduated in years (yyyy), months (mm), and days (dd) as applicable. If dates are presented, the format shall be specified.

NOTE The format in which the date is presented can be configurable to user requirements.

Indicative devices for direct or indirect measure of VH2O2 concentration

Several different parameters with associated units may be used for indication of the parameters used to directly or indirectly control, monitor and record VH2O2 concentration for a particular sterilization cycle (see 6.5.5).

The conversion of the results gained from the applied measurement method for indication shall be described in the user instructions to allow appropriate interpretation of the information. The displayed parameter and its unit shall be clearly indicated, the format shall meet the accuracy and resolution requirements for the intended interpretation of the result.

Temperature indicating devices

The temperature indicating devices shall:

a) indicate in degrees Celsius;

b) have a scale which includes the range 0 °C to 80 °C;

NOTE Outside the EU, alternative temperature units can be used.

c) have a resolution not exceeding 0,1 K.

Pressure indicating devices

The pressure indicating devices shall:

a) indicate in pascals (preferred) or millibars (non-preferred);

b) include the scale range from 0,5 times of the minimum operating pressure up to 100 kPa absolute pressure;

NOTE Outside the EU, alternative pressure units can be used.

c) have a resolution not exceeding the measurement error of the actual value.

Cycle parameter indications

Sterilizers instrumentation shall make available to the operator at least the following parameters of the current cycle:

a) chamber temperature for indication;

b) chamber temperature for control;

c) chamber temperature for independent data collection and recording;

d) absolute pressure in the chamber for indication; for double-ended sterilizers this indication shall be provided at each end;

e) absolute pressure in the chamber for control;

f) absolute pressure in the chamber for independent data collection and recording;

g) the amount of sterilant used in the current sterilization process for control (see 6.5.5);

h) the amount of sterilant applied to the current sterilization process for independent data collection and recording (see 6.5.5 and 6.3);

i) time information of cycle progress for indication and control;

j) time information of cycle progress for independent data collection and recording.

6.6.4.6 Instrumentation in 6.6.4.5 for a) and b) as well as d) and e) may be combined.

6.6.4.7 The readings a), d) and i) in 6.6.4.5 may be incorporated into a system whereby the display of any measurement may be selected by the user.

6.6.4.8 If the timers for i) and j) are synchronized, only one of them may be used for indication, control, data collection and recording.

NOTE Time information i) and j) in 6.6.4.5 are synchronized, for example with reference to a real time clock of the automatic controller.

Conformance for 6.6 is demonstrated by inspection (see 10.1.4).

6.4 Recorders

6.7.1 Sterilizers shall be fitted with means to collect and retain the cycle parameters and values of the process variables (as specified in 6.5.11) for recording.

6.7.2 The recorded data shall allow further data processing and shall enable evaluation of the operating cycle for conformity with the given specifications. This evaluation can be used for release of sterilized product, see 10.2.

NOTE Examples of concepts for control and monitoring systems and the interrelationship between control and recording are discussed and illustrated in Annex I.

6.7.3 If used for external recording, the transferred data shall allow the external system to generate records, which are compliant with all applicable specifications of 6.7.

NOTE Sterilizer identification, cycle number and load identification can be recorded automatically.

6.7.4 The recorders shall cover the scale range applicable to the operating cycle(s). Recorders shall have specified accuracy or maximal permissible errors sufficient to identify deviations from the tolerances of the specified cycle parameters and process parameters.

6.7.5 The recording system shall be independent such that the measuring chain as well as value data processing and printed values are separate from the cycle control functions (see also Annex I).

6.7.6 The records shall be either electronic data, or printed, or both. The print-out may be either in graphical or tabular form.

Table 3 provides an example for data to be recorded with reference to an example of a cycle profile in Figure 1.

Table 3 — Example for VH2O2 operating cycle and data to be recorded (for cycle profile, see Figure 1)

Program step		Time	Temperature	Pressure	VH2O2 concentration^a
Program step		Time	Temperature	(measured values)	VH2O2 concentration^a
1	start of the operating cycle^b	X
1 - 3	conditioning stage^c	X	X	X
2	start of exposure phase	X	X	X	X
3	start of holding time	X	X	X	X
4	start of air/inert gas injection pulse(s) (if applicable)	X	X	X	X
5	end of air/inert gas injection pulse(s) (if applicable)	X	X	X	X
6	end of holding time and start of purging stage	X	X	X	X
6–7	purging stage^c	X	X	X
7	end of purging stage and start of air admission	X		X
8	cycle complete	X
NOTE Designing the cycle using an even number of equivalent cycle stages can support the application of reduced cycle concepts (see 10.3.2 and D.2).
^a From direct or indirect measurement (see 6.5.5). ^b In addition also date, sterilizer identification, cycle identification and cycle counter number to be recorded. ^c Recording of time and controlled pressure switch points only.

Key

Y1	pressure	a	start of cycle
Y2	temperature	b	conditioning stage
Y3	concentration	c	holding time
t	time	d	purging stage

NOTE The pressure profile (Y1) shown by the dashed lines gives an example of options for air / inert gas injection pulses.

Figure 1 — Schematic example of a VH2O2 operating cycle profile (for programme step numbering and related operating cycle stages, see Table 3)

6.7.7 Printed and stored records shall be retrievable. The length of time that these records shall remain retrievable and readable, and the storage conditions under which this will be achieved, shall be specified.

NOTE National regulations can apply to the length of time records can be retained.

6.7.8 Printed records shall be readable when viewed at a distance of (250 ± 25) mm with normal or corrected vision at an illumination of (215 ± 15) lx.

6.7.8.1 The components for recording of data and/or printing of the records may be either:

a) part of the sterilizer, or

b) a specified interface using specified data format connecting the sterilizer by a data link to an external system.

6.7.8.2 If analogue presentations of records are generated, they shall allow:

a) temperature differences of 1 K to be readable;

b) pressure differences of less than specified maximum measurement error (see 6.5.3.2) to be readable;

NOTE Since during the complete cycle the range of pressure values to be recorded can comprise several decades (e.g. from 1 Pa through 100 kPa), different scale ranges for different operating stages or a logarithmic scale for graphical recording of the pressure values can be used.

c) the operating cycle shall be plotted completely.

Conformance for 6.7 is demonstrated by inspection (see 10.1.4).

7.0 Services and local environment

7.1 General

7.1.1 For Clause 7 the conformance is demonstrated by inspection (see 10.1.4).

7.1.2 The requirements on items that are not part of the sterilizer as the defined product but are needed for the sterilizer to perform as intended shall be specified, including but not limited to:

a) the necessary services;

b) the surrounding environmental conditions;

c) the supporting infrastructure.

7.1.3 The sterilizer shall be provided with means to isolate each service. Isolation of a service shall not create a hazardous situation.

7.1.4 Means shall be provided to prevent the ingress of particulates from the services or environment that could affect the performance of the sterilizer or products being sterilized.

NOTE Strainers or filters of a relevant pore size rating can be used.

7.1.1 Sterilant and sterilizing agent

7.2.1 The sterilant, its container and associated packaging, shall be specified and clearly and uniquely identified for its specific use and for which sterilizer it is intended for use in.

NOTE H₂O₂ is classified as “hazardous substance” and specific safety regulations can apply.

7.2.2 The sterilant containers shall be designed in such a way that they withstand the mechanical stress during the intended handling as well as unintentional stress that can reasonably occur (see 5.7.2).

7.2.3 The sterilant container shall be labelled with:

a) the H2O2 concentration;

b) classification, hazard codes and safety data sheet (see 11.2 d));

c) manufacturer identification (see 11.5.1 f));

d) production lot number;

e) storage requirements;

f) the expiry date (see also 5.7.2, 11.2 d).

7.2.4 The variables affecting vaporization of the sterilant shall be identified and controlled within their tolerances.

7.2.5 The following requirements for the sterilizing agent shall be specified:

a) composition;

b) means of generation;

c) control and monitoring parameters.

7.1.2 Electrical supply

The following requirements for the electrical supply shall be specified:

a) number of phases (and neutral, if required);

b) minimum and maximum voltage;

c) frequency.

7.1.3 Water

If required for example for cooling purposes, the specification for the water supply shall be provided. (see 11.2 c).

NOTE 1 Water of a hardness value between 0,7 mmol/l and 2,0 mmol/l, are generally accepted values used for the design of the sterilizer. Hardness values outside these limits can cause scaling and corrosion problems.

NOTE 2 National regulations can require a backflow protection in the supply line. See also EN 1717.

7.1.4 Steam

If the sterilizer requires an external steam supply, the requirements for steam to be supplied to the sterilizer shall be specified for each specific use within the sterilizer.

7.1.5 Vacuum

If the sterilizer requires an external vacuum system, the requirements for the external vacuum system shall be specified (see also 5.3.3.1 and 5.3.3.2).

7.1.6 Lighting

The user interfaces of the sterilizer shall be designed to allow operation with a minimum external illumination of 200 lx.

7.1.7 Drainage and discharges

If the sterilizer requires drainage the requirement shall be specified [see 11.2 c)].

NOTE EN IEC 61010‑2‑040:2021, 13.1 including subclauses provide additional requirements for drainage and discharges affecting safety and environmental aspects.

7.1.8 Compressed air

If the sterilizer requires compressed air, the requirement shall be specified.

NOTE These requirements can consist of filtration requirements, oil and water content, supply pressure.

7.1.9 Air and inert gases

7.10.1 Microbial contamination of the load shall be prevented during the sterilization cycle.

7.10.2 If a filter is fitted to the sterilizer to prevent microbial recontamination during admission of air or other gases, it shall be readily accessible for replacement. The filter shall be capable of retaining at least 99,5 % of particles with a diameter of 0,3 μm at a pressure difference of 100 kPa and at maximum airflow.

7.1.10 Ventilation and environment

The environmental conditions necessary for the correct operation of the sterilizer shall be specified (e.g. temperature, humidity, ventilation air flow or number of room air changes per hour).

8.0 Emissions

8.1 Electromagnetic emissions

8.1.1 Sterilizers shall conform with EN IEC 61326‑1:2021, 7.2, regarding electromagnetic emissions.

8.1.2 Sterilizers operating in areas intended for medical electrical equipment or in the vicinity of other sensitive equipment shall be regarded as Class B equipment as specified in EN IEC 61326‑1:2021.

Conformance is demonstrated by inspection (see 10.1.4).

8.1.1 Noise

8.2.1 For the Clause 8.2, conformance is demonstrated by inspection of the technical documentation.

8.2.2 Noise emission from the sterilizer, with the exception of any audible alarm (see 6.4), shall be reduced by design and selection of components with low noise emission levels, particularly at source.

8.2.3 If equipment produces noise (except alarms) at a level which could cause a hazard, estimate the sound pressure level:

a) if the estimate is below 60 dB (A), a statement in the technical documentation that the sound pressure level is below 70 dB (A) shall be provided;

b) if the sound pressure level is estimated to be above 60 dB (A), A-weighted sound power and emission sound pressure levels shall be determined and specified for each type of sterilizer. For testing and calculation EN ISO 3746:2010 shall apply. The measured sound pressure level shall be provided in the technical documentation.

NOTE 1 Estimation of sound pressure levels can be performed using a hand-held sound meter.

NOTE 2 See Directive 2003/10/EC [58] on noise risk.

8.2.4 When conducted (see 8.2.3), the noise emission tests shall be performed in standard operation with empty chamber.

NOTE 1 For test and calculation, other methods of demonstrated equivalence can be used. Guidance is provided in EN ISO 3740.

NOTE 2 Guidance to reduce noise at source is provided in EN ISO 12100:2010, 6.2.2.2, 6.2.3, and 6.3.4.2.

8.2.5 If specified, the stated emission sound pressure level shall apply for the operator’s position in front of the sterilizer at a distance of 1 m and a height of 1,6 m.

8.2.6 The standard deviation for the sound power and emission sound pressure levels shall be +5 dB in accordance with EN ISO 3746:2010, Table D.1.

8.2.7 If changes or modification of tested sterilizer and ancillary equipment does not cause additional noise that can cause a hazard (see 8.2.2), further testing and change of the specification can be omitted.

8.1.2 Exhaust emissions

8.3.1 The removal of VH2O2 from the chamber and load in the operating cycle shall ensure that:

a) Processed products are safe for use;

b) the maximum stipulated concentration of VH2O2 released into the immediate work environment, in which personnel are working without protective equipment, will not be exceeded when the load is removed from the sterilizer.

NOTE See EN ISO 10993‑1 and ISO 10993‑17 for information related to biological safety of materials and health risk assessments.

8.3.2 The concentration in air of H₂O₂ shall be measured in accordance with EN IEC 61010‑2‑040:2021 as described in Annex F.1 of this document.

NOTE In many countries national regulations exist for maximum H₂O₂ concentration in air for occupational safety and health purposes (see also H.2.2).

8.3.3 Liquid residues of H₂O₂ shall not be present after processing of loads as described in F.2.

Conformance for 8.3 is demonstrated by inspection (see 10.1.4).

8.1.3 Heat emission

8.4.1 Pipework at a temperature greater than 60 °C shall be thermally insulated to reduce heat transmission to the environment except where this will interfere with the function of the sterilizer.

8.4.2 The maximum heat in Joules transmitted by the sterilizer to the surrounding air during an hour of continuous operation with the sterilization cycle giving the highest emission of heat, shall be specified based on an ambient temperature of (23 ± 3) °C.

Opening the sterilizer and removal of the load after end of an operating cycle shall be included in the one-hour period.

Conformance for 8.4 is demonstrated by inspection (see 10.1.4).

9.0 Test instrumentation and test devices

Test instrumentation shall provide means to record the values of cycle variables and process variables in accordance with Annex B.

10.0 Performance assessment

10.1 General

10.1.1 Tests in this document are type tests to be carried out on samples of sterilizer or parts whose design and construction are representative of production units. Their purpose is to verify that the design and construction ensure conformance with the requirements of this document including verification of microbicidal efficacy and sterilizing agent penetration into specified test loads and test items. The sequence of tests is optional unless otherwise specified. Tests for specific sterilizers (e.g. industrial application) designed for their specific applications are works tests or additional type tests specific to the configurations of the specific production units (see Annex A).

NOTE The microbiological type tests described in this document are not intended to replace the requirements for process validation (installation qualification, operational qualification and performance qualification) as specified in ISO 22441:2022.

10.1.2 Tests on subassemblies that meet the requirements of the relevant standards specified in this document, and used in accordance with them, shall be repeated during type tests of the whole equipment.

10.1.3 If test loads or specific test devices are necessary in type testing to demonstrate claimed performances of a cycle for specific types of load configurations as stated by the intended use, these test loads and test devices shall be specified.

10.1.4 Where conformity statements in this document require inspection, this may include examination of the sterilizer:

a) by measurement;

b) markings;

c) information supplied to the user e.g. information prior to installation (11.3), instructions for use and maintenance (11.5);

d) technical documentation e.g. manufacturers technical file, failure mode analysis;

e) data sheets of the materials or components from which the sterilizer is manufactured.

NOTE The inspection will demonstrate that the sterilizer meets the applicable requirements, or will indicate that changes to the sterilizer are needed.

10.1.5 The type tests described in Clause 10 and summarized in Table 4 below shall establish the capability of the sterilizer in performing a process that is capable of adequately delivering sterilizing agent to the chamber and the load.

Table 4 — Recommended testing to demonstrate sterilizing agent exposure

Variable	Demonstration	Test procedure	Test procedure in accordance with
Chamber temperature mapping	Homogenous distribution of temperature	Chamber mapping	Annex D
Pressure profiling	Controlled and measured pressure	Pressure profile evaluation	Annex D
Sterilant supply	Controlled and measured supply to the process	Sterilant supply control	Annex D

10.1.6 This document specifies penetration type test devices (PTTD), and methods (see Annex D) that may be used to demonstrate minimal penetration performance.

NOTE Type testing with PTTD cannot replace microbiological performance qualification in accordance with ISO 22441:2022.

10.1.7 In order to achieve reproducible sterilizing performance on a defined product (see ISO 22441), the corresponding cycle variables including their tolerances shall be defined and as far as applicable, controlled (6.3), monitored (6.3), and recorded (6.7). Figure 2 gives an example of VH2O2 operating cycle profile demonstrating relationship of cycle variables.

NOTE The following are recognized as the process variables most relevant for sterilizing performance (see ISO 22441) are:

− H2O2 concentration;

− temperature;

− pressure;

− time.

Key

P	pressure	3	following holding time in reduced cycle
T	temperature	4	exposure phase, first reduced cycle
C	VH202-concentration	5	exposure phase, second reduced cycle
t	time	6	purging stage
1	conditioning stage	T_s	VH2O2 temperature band
2	first holding time in reduced cycle	C_op	operating VH2O2-concentration band

Figure 2 — Schematic example of a VH2O2 operating cycle profile based on two consecutive reduced cycles

10.1.9 Annex C of this document specifies test loads that shall be used to demonstrate conformity with minimum performance requirements of this document.

NOTE A test load does not necessarily mimic a configuration of medical devices. The suitability of an operating cycle for a particular product can be justified by validation (see ISO 22441:2022).

10.1.1 Attainment conditions

10.1.2 Temperature reference measurement point

The reference measurement point shall be determined such that throughout the specified holding times, the temperature at this point correlates with the temperature in the usable chamber space.

10.1.3 Operating temperature band

The operating temperature band T_s (see Figure 2) shall be specified.

10.1.4 Temperature profile

10.2.3.1 Throughout the sterilization cycle the temperature at the reference measurement point shall not exceed the maximum temperature specified, Tmax (see Figure 2).

10.2.3.2 During the specified holding time(s) the measured temperatures shall:

a) be within the VH2O2 temperature band T_S (see Figure 2).

b) allow the correlation to be demonstrated between the temperature measured at the reference measurement point and the temperatures measured in the usable chamber space;

c) not exceed the stated maximum level.

10.2.3.3 During testing in accordance with Annex D the temperature measured at the reference measurement point and the temperatures in positions as specified in D.2.3 and D.2.5 shall be used for the evaluation of the temperature profile.

NOTE A sterilization cycle can comprise more than one holding time (see Figure 2). The operating temperature bands of different holding times can be specified individually.

10.2.3.4 Throughout the sterilization cycle, the temperature in the usable chamber space shall not exceed 60° C.

10.1.5 Pressure profile requirements

10.2.4.1 Pressure measurement for the evaluation of the pressure profile shall use absolute pressure values.

10.2.4.2 During testing in accordance with Annex D, the pressure profile shall be evaluated by measurement of the operating cycle pressure using a time sampling frequency less than or equal to 1s. The measurement shall include maximum and minimum values to establish the profile of all sequences (see Table 4 and Figure 2) as well as data sufficient to evaluate tolerances and the rate of pressure change in applicable parts of the sterilization cycle. The result shall be compared with corresponding specifications stated for the sterilizer.

10.2.4.3 Throughout the sterilization cycle the pressure profile and the limiting values specified for the pressure profile shall be attained.

10.2.4.4 To minimize damages to the products and their sterile barrier systems the maximum rate of pressure change measured shall not exceed 1 000 kPa/min when measured over a period of 3 s.

During the cycle the pressure profile shall be monitored and controlled to be within the tolerances specified.

10.1.6 Sterilant and sterilizing agent

10.2.5.1 The control parameters to supply the sterilant and generate the sterilizing agent shall be achieved reproducibly.

10.2.5.2 During the exposure stage the specified cycle parameter(s) for sterilizing agent control (e.g. partial pressure, concentration, dose) shall:

— establish the reproducible application of sterilizing agent to the chamber load;

— verify that the H₂0₂ concentration is within the operating concentration band-C_op of Figure 2.

NOTE The range of the operating H₂O₂ concentration can vary for different loads inside the specified H₂O₂ concentration band.

Conformance for 10.2 is demonstrated by inspection (see 10.1.4).

10.2 Microbiological performance

10.2.1 General

Microbiological type tests are used to demonstrate that the sterilizer is able to achieve microbicidal efficacy with specified small and full type testing loads. Such microbiological type test shall be performed at reduced cycle.

NOTE 1 VH2O2-sterilization cycles usually start with an air removal, and conditioning stage (see 1 to 3 in Figure 1) followed by a multiple of the following sequence of sterilizing agent injection (2-3 in Figure 1) to establish a holding time (3 to 6 in Figure 1), followed by inert gas or air injection pulse(s) (4-5 in Figure 1), and ending with evacuation stage (7 in Figure 1). A reduced number of these VH2O2 injection-hold-vacuum sequences are used for microbiological type testing and of sufficient number to provide a type test challenge to the equipment. Most commonly, the number of above sequence is equivalent to those used in half-cycle process validation.

NOTE 2 Microbiological type tests are used to demonstrated that the sterilizer achieves inactivation of microbiological indicators in specified type test conditions. The ability of the sterilizer to deliver a defined Sterilization Assurance Level is verified by the implementation of methods described in ISO 22441:2022.

10.2.2 Microbiological efficacy at reduced cycle

10.3.2.1 Inspection of the cycle profile records and comparison with the specification (see 11.5.1 c) and d)) shall confirm that an effective reduced cycle concept with defined reproducible conditions is specified and applied for all sterilization cycles.

10.3.2.2 All sterilization cycles shall ensure that biological indicators as specified in B.7.5 demonstrate non-viability when tested with small load and full load as specified in C.2.2 and C.2.3 respectively and with the test methods described in D.2.2, D.2.4 and D.2.6.

Conformance for 10.3 is demonstrated by inspection (see 10.1.4).

10.3 Penetration performance

Each sterilizer shall provide at least one sterilization cycle which is capable of demonstrating minimum penetration performance using a penetration type test device (PTTD) as specified in B.7.2 and biological indicators as specified in B.7.5, and with the test methods described in D.2.7.

NOTE This PTTD is not intended to be used as the basis of performance claims and labelling.

Conformance for 10.4 is demonstrated by inspection (see 10.1.4).

10.3.1 Load dryness

The sterilization cycle shall ensure that no parts of the load or sterile barrier system have any visible wetness after processing. and with the test methods described in D.2.9.

Conformance for 10.5 is demonstrated by inspection (see 10.1.4).

11.0 Information to be supplied

11.1 General

11.1.1 Information to be supplied shall be in human-readable form and conform with the requirements in 11.2 to 11.5.

NOTE This information can also be supplemented by machine-readable information such as RFID or bar codes.

11.1.2 The following information elements shall be used:

a) Units of measurement shall be as specified in ISO 8000‑1:2022 (see also EN ISO 20417:2021, 5.1);

b) Graphical information shall be as specified in EN ISO 15223‑1:2021 (see also EN ISO 20417:2021, 5.2);

c) Language identifiers shall be as specified in ISO 639:2023 (see also EN ISO 20417:2021, 5.3);

d) Country identifiers shall be as specified in EN ISO 3166‑1:2020 (see also EN ISO 20417:2021, 5.3);

e) Date format shall be as specified in ISO 8601‑1:2019 (see also EN ISO 20417:2021, 5.4).

Conformance for 11.1 is demonstrated by inspection (see 10.1.4).

11.1.1 Information to be available prior to purchase

At least the following information shall be provided to prospective purchasers upon request:

a) a clear description of the intended use of the sterilizer [see EN ISO 20417:2021, 6.6.2 a) 2)], and details of all pre-programmed operating cycle and their application;

b) the sterilizer dimensions, including required space requirements for operation and associated services;

c) details of services required for supply, drainage, and ventilation;

d) details of the sterilant for the sterilizer, including composition, safety data sheet and storage requirements;

e) details of maximum consumption of sterilant per sterilization cycle;

f) the total heat in Joule transmitted to the environment when the sterilizer is operated continuously for one hour or per cycle in an ambient temperature of (23 ± 2) °C in still air;

g) dimensions of the usable chamber space in accordance with 5.2.2.2 and the loading capacity;

h) the noise emission information required by 8.2.3;

i) any restriction for installation or operation (e.g. due to EMC properties).

Conformance for 11.2 is demonstrated by inspection (see 10.1.4).

11.1.2 Information prior to installation

At least the following information shall be provided prior to installation of the sterilizer on site:

a) instructions for handling during transport and storage such as conditions for stability, orientation, temperature, humidity and ambient pressure;

b) installation instructions including overall mass of the sterilizer as well as the clearance required for operational and maintenance access to the sterilizer; (see also EN IEC 61010‑2‑040:2021, 5.4.3 and 5.4.5);

c) safety requirements for installation as required by EN IEC 61010‑2‑040:2021, 5.4.3, 5.4.3.101, 7.1.101;

d) ambient lighting requirements for maintenance area(s);

NOTE Guidance for lighting is provided in EN ISO 12100:2010, 4.8.6 and EN 1837:2020, Clauses 4 and 5.

e) the noise emission information required by 8.2.3 for any additional device, delivered with the sterilizer but separate from it, and which is necessary for its operation;

f) declaration of compliance with the EMC requirements in 5.1.2.4 and 8.1;

Conformance for 11.3 is demonstrated by inspection (see 10.1.4).

11.1.3 Marking and labelling

11.4.1 Markings and labels shall be permanently and legibly marked. When symbols are used harmonized symbols in accordance with EN ISO 15223‑1:2021 shall be used. Additional symbols, if used, shall be described in the instructions for use.

11.4.2 Markings regarding safety and environmental aspects of the sterilizer shall be specified in accordance with EN IEC 61010‑2‑040:2021, 5.2.

11.4.3 Markings shall include at least:

a) name and address of the manufacturer.

NOTE 1 The address information is sufficient to be able to contact the manufacturer.

b) name and address of authorized representative within the European Union in the case where the manufacturer does not have a registered place of business in the EU;

NOTE 2 The address information is sufficient to be able to contact the authorized representative.

c) the CE mark accompanied by the European registration number of the notified body engaged for medical devices;

d) Unique Device Identification (UDI);

e) model;

f) serial number

g) production year;

h) symbols or marking for indicating and operating devices.

Conformance for 11.4 is demonstrated by inspection (see 10.1.4).

11.1.4 Instructions for use

11.5.1 The instructions for use shall accompany the sterilizer. It shall include at least:

a) name and full address of the manufacturer;

b) the CE mark and the notified body identification number;

c) general description of the field of application with available sterilization cycles, including values and tolerances for the cycle parameters for which efficacy and safety has been established;

d) any implication, restriction or limitation of performance specifications and respective testing concerning defined products or product characteristics to be considered for especially offered operation cycles;

e) the operating temperature (including tolerances) specified for each of the available sterilization cycles;

f) identification of consumables and accessories dedicated to the sterilizer;

g) instructions for safe disposal of the sterilizer;

h) dimensions of the chamber;

i) description of controls as well as indicating, operating, monitoring and recording devices;

j) instructions for the actions to be taken in case of malfunctions;

k) instructions for maintenance tasks and their frequency, including cleaning;

l) details of performance tests to be used to ensure normal operation of the sterilizer and the frequency at which they should be carried out;

NOTE The frequency and extent of validation, and requalification activities are not a part of the sterilizer documentation. National guidance can exist.

m) brief description of safety devices;

n) further details of sterilizer operation for safety as required by EN IEC 61010‑2‑040:2021, 5.4.4;

o) instructions for loading, unloading and load release;

p) compatibilities of the sterilization process with load materials;

q) instructions on the protective measures to be taken by the users, including, where appropriate, the personal protective equipment to be used;

r) warnings and precautions about residual risks;

s) date of issue or date of latest revision of the instructions.

11.5.2 Before the installation qualification, the following information shall be available to the user:

a) maintenance manual including at least:

1) maintenance activities including maintenance intervals;

2) safety device checks and settings;

3) wiring and piping diagrams;

4) guidance for service and spare parts;

5) Information to assist diagnosis of specified faults.

b) manufacturer’s declaration of conformity with this document;

c) details of required data, services and sterilant (see 7.2);

d) the location of the reference measurement point(s);

e) additional generic information needed to operate the device safely;

f) cleaning instructions for the chamber and the exterior including the type of agents to be used;

g) further details of maintenance of safety sterilizer as required by EN IEC 61010‑2‑040:2021, 5.4.5;

h) instructions for safe disposal of the sterilizer.

Conformance for 11.5 is demonstrated by inspection (see 10.1.4).

12.0 Shipping container

12.1 The sterilizer shipping container shall be designed to protect the sterilizer and preserve its characteristics during intended transport, storage and installation.

12.2 The shipping container shall be labelled with the information given in 11.4.3, a) to g).

12.3 Instructions for handling, unpacking, transport and storage shall be clearly indicated on the outside of the shipping container.

Conformance for Clause 12 is demonstrated by inspection (see 10.1.4).

(informative)

Test programme
1. General

A.1.1 The series of tests listed in Table A.1 and specified hereafter are tests intended for use with reference loads in demonstrating conformity with performance requirements specified in this document.

NOTE 1 Further tests according to EN IEC 61010‑2‑040:2021 can be required. In addition, other tests in ISO 22441:2022 can be required.

Table A.1 — Recommended test programme (summary)

Test	Application	Requirements	Test procedure	Type tests^a	Works tests^b
Chamber temperature test	Sterilizer	5.2.4	D.2.1	X
Microbiological empty chamber distribution test for all cycles	All sterilization cycles (reduced cycle)	10.3.2	D.2.2	X
Small load physical performance test	All sterilization cycles	10.2.3, 10.2.4, 10.2.5, 10.4, B.6	D.2.3	X
Small load microbiological performance test	All sterilization cycles (reduced cycle)	10.3.2	D.2.4	X
Full load physical performance test	All sterilization cycles	10.2.3, 10.2.4, 10.2.5, 10.4, B.6	D.2.5 F.2	X	X^c
Full load microbiological performance test	All sterilization cycles (reduced cycle)	10.3.2	D.2.6	X
Penetration performance test with PTTD	At least one sterilization cycle	10.4	D.2.7	X	X
Air leakage test	Leak test cycle	6.7.2	D.2.8	X	X
Load Dryness test	All sterilization cycles	10.5	D.2.9	X	X
H₂O₂ in ambient air	All sterilization cycles	8.3.2	F.1	X
^a For verification of reproducibility the type tests should be triplicated. ^b Some tests specified in this table may be considered for IQ. ^c Sterilizer internal instrumentation shall be calibrated.

NOTE 2 Environmental aspects can be considered during testing by planning and performing the tests in a logical succession. Therefore, the risk for unnecessary repetitions of tests due to the need for technical alterations of the sterilizer in a late stage of the test succession can be minimized. By experience physical testing has shown to cause most adjustments. A logical succession of the tests in Annex A can be as follows (see Table A.1):

− pre-heating test;

− air leakage test;

− small load physical performance test including drying test;

− full load physical performance test including drying test;

− microbiological test.

A.1.2 Before carrying out any of the tests, calibration shall be performed in accordance with 4.3. The accuracy and adjustment of temperature and pressure measuring devices as well as the monitoring equipment for the sterilant supply to the process shall be checked, and that they comply with the requirements of 6.5.

A.1.3 If during the tests adjustment(s) is (are) made to the sterilizer during a test sequence such that a new sterilizer type as defined in 4.1 is created, the sequence of tests shall be repeated.

A.1.4 For usable chamber spaces larger than 1 000 l a justified increase of the number of indicators, measurement points and load units should be considered, which would allow to get a good insight into the homogeneity of the process conditions in the chamber and the load.

The number of indicators, measurement points and load units shall be established on a case to case basis.

1. Type test

The type test is used to demonstrate that the operational specifications of each sterilizer type are fulfilled before it is placed on the market. When performed as specified in Table A.1 for each sterilizer type the series of tests are suitable as type tests with respect to performance requirements to this document (see Clause 10).

1. Works test

The series of works tests listed in Table A.1 are reference tests recommended for use in demonstrating conformity with performance requirements specified in this document.

Some of these tests shall be performed or repeated after final installation on site.

1. Installation qualification (IQ) provisions

A.4.1 Requirements and guidance for IQ are given in ISO 22441:2022, 9.2.

(normative)

Test instrumentation and test devices
1. General

B.1.1 The test equipment and test devices specified hereafter shall allow verification of the calibration and proper function of the sterilizer indication, monitoring and recording instrumentation. It shall further allow performing the test procedures as specified in Annex D according to the test programme suggested in Table A.1.

B.1.2 The recording systems used for documentation of the cycle profiles shall allow synchronization of the individual records of the relevant cycle variables. Preferably a combined system is used to record synchronously these variables (e.g. pressure, temperature, sterilant supply/concentration) using the same time scale.

NOTE The recording instrument can be either an external device connected to the sensor elements using the test connections of the chamber (see 5.2.5), or a data logger system.

1. Pressure instrumentation

B.2.1 Test pressure instruments shall be used to check the status of pressure indicating and recording equipment of the sterilizer. Absolute pressure transducers shall be used.

B.2.2 The scale range of the test pressure instrument(s) shall include at least the cycle parameter scale range specified for the sterilizer. The maximum permissible errors of the test pressure instrument shall not exceed 0,5 times the maximum permissible errors of the instrument to be tested.

NOTE Due to the range of pressures in the process, it can be necessary to have more than one pressure sensor.

B.2.3 The test pressure instrument shall have a valid calibration certificate.

B.2.4 Calibration of the test pressure instrument shall be carried out in accordance with its user instruction (see also A.1.2).

1. Pressure recording

B.3.1 The sampling rate for each channel shall be 1 s or less. All data sampled shall be used for the interpretation of the results.

B.3.2 The scale range for analogue pressure records, if used, shall include 0 Pa to 100 kPa absolute.

NOTE Since during the complete cycle the range of pressure values to be recorded can comprise several decades (e.g. from 10 Pa to 100 kPa), different scale ranges for different operating stages or a logarithmic scale for graphical recording of the pressure values can be used.

B.3.3 Pressure recording instruments shall allow recording in increments of not more than 1 % of the currently used decade of the measurement range, or 10 Pa, whichever is greater.

B.3.4 The measurement range shall include 0,1 times the minimum operating cycle pressure up to 100 kPa (absolute).

B.3.5 The total limit of measurement error for indication and recording shall not exceed 5 % of the actual value, or 20 Pa, whichever is greater, when measured in an ambient temperature of (20 ± 3) °C.

B.3.6 The time constant (0 % to 63 %) for rising pressure shall not be greater than 0,2 s.

B.3.7 Calibration of the pressure recording instrument shall be carried out in accordance with the user instructions (see also A.1.2).

1. Temperature probes

B.4.1 Temperature sensors used for the temperature probes shall be either platinum resistance and comply with Class A of EN IEC 60751:2022 or thermocouple and comply with one of the types of Tolerance Class 1 of EN 60584‑1:2013, and shall have a response time of Ƭ_0,9 ≤ 5 s when tested in running water in accordance with EN IEC 60751:2022, 6.5.2.

B.4.3 The conditions to which temperature probes are exposed, e.g. pressure, sterilant, shall not affect its performance characteristics.

B.4.4 Calibration of the temperature probes shall be carried out with the user instructions (see also A.1.2).

1. Temperature recording instrument

B.5.1 The recording instrument shall record the temperature from at least the number of temperature probes as specified in Table D.1. The sampling rate shall be 1 s.

B.5.2 Temperature recording instruments shall allow recording in increments not exceeding 0,1 K and the scale range shall include 0 °C to 80 °C.

B.5.3 The maximum errors between 10 °C to 80 °C shall not exceed 0,25 K when tested at specified operating temperature of the instrument (e.g. ambient temperature).

B.5.4 After adjustment the temperature measured by all temperature probes shall not differ by more than 0,2 K when immersed in a temperature source within the temperature band. The temperature indication of the source shall have an uncertainty of measurement less than ± 0,1 K at the temperature measured.

B.5.5 Calibration of the temperature recording instrument shall be carried out with the user instructions (see also A.1.2).

B.5.6 The temperature recording instrument shall be calibrated in accordance with its user instructions and calibration shall include a temperature which is within the operating temperature band.

1. Sterilant supply and concentration measurement system

B.6.1 The instrumentation for measurement and recording of the amount of sterilant supplied during the process, shall allow verification of the functionality and the calibration of the system for monitoring, control and registration of the sterilant supply as used for the sterilizer. The verification procedure shall include quantitative evaluation of the correlation between the measurement result for the supplied sterilant and for the sterilizing agent.

NOTE Instruments utilizing several principles to monitor the mass flow or volume of H2O2 supplied to the process, or to measure or calculate the concentration or partial pressure of H2O2 inside the chamber are commercially available. No preference or respective recommendation for selection can be given here (see also Annex E).

B.6.2 Calibration of the measurement system shall be in accordance with its user instructions and shall include the scale range which is relevant for cycle control and monitoring (see 10.2). The measurement error shall be less than that needed to verify 50 % of the error specified by 6.5.5 for the monitoring system of the sterilizer.

1. Penetration Type Test devices (PTTDs)
  1. General

B.7.1.1 Penetration type test devices are intended to demonstrate specific process performances or respective limitations. They shall be used to justify in part the acceptability of a sterilization cycle for specific generalized load configurations.

B.7.1.2 The penetration type tests device shall be used to demonstrate a minimum capability of the applied sterilization cycle for the sterilizing agent to penetrate configurations of products comprising volumes and surface structures.

NOTE 1 A test load does not necessarily mimic a configuration of medical devices. The acceptability of a sterilization cycle for a particular product configuration will require validation (see ISO 22441:2022).

NOTE 2 The use of a biological indicator within a PTTD is intended only to demonstrate directly only the penetration capability of the applied sterilization cycle for the sterilizing agent. It is for this reason that the biological indicator population is 1 × 105 (see B.7.5.3). The results of the penetration test are not intended be used to demonstrate compliance with 10.3.3.1, for which a higher population of spores is used in a sterile barrier system (see B.7.5.4).

- 1. PTTD construction

B.7.2.1 The penetration type test device PTTD shall demonstrate the penetration performance or microbial inactivation performance, respectively, for small and long hollow lumen items which are closed at one end. The use of this PTTD shall verify the specified conditions for the required efficacy being achieved at the indicator inserted into the PTTD receptacle at the closed end.

B.7.2.2 The dimensions of the PTTD shall be in accordance with Figure B.1. The receptacle shall be made from stainless steel 1.4401 (X5CrNiMo17-12-2, AISI 316), 1.4404 (X2CrNiMo17-12-2, AISI 316L), or 1.4571 (X6CrNiMoTi17-12-2, 316Ti).

Figure B.1 — PTTD receptacle dimensions (Source: EN ISO 11140‑6:2022, Figure E.3 Reference hollow device receptable casing and pin dimensions)

B.7.2.3 The tube of the PTTD shall be made from stainless steel 1.4401 (X5CrNiMo17-12-2, AISI 316), 1.4404 (X2CrNiMo17-12-2, AISI 316L), or 1.4571 (X6CrNiMoTi17-12-2, 316Ti) with a diameter 3 mm × 0,5 mm (inner diameter 2 mm), and a length of 100 mm. The tube inserted to the receptacle has to be sealed appropriate, e.g. by silicone tube.

NOTE Due to catalytic reactions of hydrogen peroxide at metallic surfaces, the hydrogen peroxide concentration inside the receptacle of the PTTD can be significantly reduced compared to that becoming effective in the receptacle of a PTTD with the same length of the tube, but this being made from PTFE/FEP. This effect can depend also on individual specific sterilization cycle parameters.

- 1. Indicator systems for PTTDs

B.7.3.1 For verification of the sterilizing agent penetration or microbial inactivation performance of a cycle a biological indicator (BI) in accordance with B.7.5 shall be inserted into the receptacle of the PTTD.

B.7.3.2 The PTTD with the respective biological indicator in place shall be used without a sterile barrier system or other wrapping.

- 1. Other type test devices

Requirement and considerations related to other type test devices are stated in 10.1.5 and 10.1.6.

- 1. Biological indicators

B.7.5.1 Biological indicators (BIs) shall comply with EN ISO 11138‑1:2017 as applicable. Documented evidence shall be provided for their suitability.

B.7.5.2 Biological indicator system shall comply with following specification:

— The carrier material shall be stainless steel 1.4301 (AISI 304), surface electro polished.

— The dimensions of the carrier strip shall be (38,0 ± 2) mm × (6,0 ± 1) mm × (0,05 ± 0,01) mm (L × W × H).

— Inoculation of the carrier with Geobacillus stearothermophilus. The Spore suspension for inoculation shall have low protein burden (Protein fragments of ingredients which are not part of the spores have to be removed from the spore solution). The inoculation procedure and spore preparation shall ensure an even distribution of spores on the carrier surface avoiding agglomeration.

— The D-value of the indicators shall be 1,8 to 2 min. Determination of D-value in accordance with liquid method of [56] Deinhard et al.

B.7.5.3 Inoculated biological indicator system in accordance with B.7.5.2 which shall be used for tests according to D.2.2 (without PTTD) shall carry a population of 1-2 × 10⁶ CFU to 1,5 × 10⁶ CFU and shall be placed inside a sterile barrier system according B.8.

B.7.5.4 Inoculated biological indicator system in accordance with B.7.5.2 which shall be used for tests inside the PTTD shall carry a population of 1 × 10⁵ CFU.

1. Sterile barrier systems
  1. General

Materials of sterile barrier systems shall not interact with the sterilizing agent to the extent that the intended performance of the sterilization cycle is not met (i.e. not contribute to the decomposition of the sterilizing agent or adsorb the sterilizing agent to the extent that the efficacy of the sterilization process is impaired) or that residuals are outside of specified limits.

NOTE Cellulosic materials such as papers or nonwovens containing cellulose, or materials that have a high absorbance of VH2O2 cannot be used in VH2O2 sterilization processes.

- 1. Sterile Barrier Systems for standard test loads

Sterile barrier systems for test loads shall comply with EN 868‑5:2018. The porous polyolefin nonwoven material shall comply with requirements of EN 868‑9:2018.

The first sterile barrier in contact with the test items respectively the devices shall have a width of 150 mm and a length adapted to the respective length of the test items of the devices.

(normative)

Test loads
1. General

The performance of the sterilizer shall be tested using test loads in accordance with this annex.

NOTE 1 The test loads used for type tests are intended to verify that the minimum performance requirements of this document are achieved and can be used for type tests and works tests. Manufacturers or users can specify if they can be used for operational qualification. They are not specified to be used for performance qualification as these loads will need to be correlated to actual loads to be processed.

A test load is not intended to mimic a configuration of medical devices. The suitability of a sterilization cycle for a particular product can be justified by validation (see ISO 22441:2022).

NOTE 2 For the purposes of the tests described in this document, a double sterile barrier system is specified. However, there is currently no requirement to use double sterile barrier system for sterilization of medical devices.

1. Test loads
  1. Test load unit

The test load unit shall consist of the following sets of items, each packaged in a double barrier system (B.8):

a) one hose made of polyvinylchloride (PVC) with a length of 1 500 mm, with an inner diameter of 4 mm and an outer diameter of 6 mm; the packaged item shall have a total weight of (40 ± 5) g;

b) one hose made of polyvinylchloride (PVC) with a length of 1 000 mm, with an inner diameter of 8 mm and an outer diameter of 12 mm and one screw made of stainless steel, M 8 × 60 (see e.g. EN ISO 4017), which is pushed into one end of the PVC hose; the packaged complete item shall have a total weight of (120 ± 10) g;

c) one rod made of low-density polyethylene (LDPE) with a length of 80 mm and a diameter of 15 mm, and one screw made of stainless steel, M 8 × 60 (see e.g. EN ISO 4017); both items packaged together shall have a total weight of (45 ± 5) g;

d) a biological indicator, as defined in B.7.5.3 located outside of package a), b), c).

NOTE 1 Items a), b) and c) are not intended to demonstrate lumen penetration performance of the cycle.

The total weight of the test load unit excluding load carrier facilities will be (205 ± 20) g.

NOTE 2 Two sets of items [type b) and c)] are used for the full load temperature profile and the pressure tests and are not sealed in advance.

NOTE 3 Disposal instructions for sterile barrier systems and, if applicable, for test items, are provided by their manufacturer.

- 1. Small load

The small load shall be composed of test load units, as defined in C.2 The number of test load units is indicated in D.1.

- 1. Full load

The full load is selected to represent a heavy loading situation for a VH2O2 sterilization cycle. It shall comprise at least 90 % in weight of the maximum load as specified for the sterilizer [see Annex J].

It shall be composed of a number of test load units, as specified in Table D.1, plus a mixture of items similar to those used in the test load units and with similar material proportions indicated.

NOTE The weight of the load support system is not included in the weight of the maximum load.

(normative)

Test procedures
1. General

D.1.1 The performance of the sterilizer shall be tested in accordance with this annex. Additionally, Table D.1 sets up requirements for the number of tests to be performed and for each type of sterilizer. The tests described in the annex shall be performed with an empty chamber, with a small load or full load as specified for each test procedure in D.2.

NOTE 1 By performing tests simultaneously, as described by the following test methods, the total number of tests and test equipment disposals is reduced. As result the burden on the environment can be reduced (see also Annex H).

NOTE 2 Microbiological tests as described in this document (see Clause 10) are not intended to verify sterility, but only cycle performance using biological indicators.

D.1.2 The test equipment shall meet the requirements of Annex B and the test loads shall comply with the specifications given in Annex C.

D.1.3 The tests used to determine the performance of the sterilizer employ various devices including temperature sensors, BIs and penetration type tests devices. The number of sensors and devices to be used is dependent upon the usable chamber space volume of the sterilizer. The number of sensors employed for each test shall be as specified in Table D.1.

D.1.4 Recommended numbers of indicators and temperature measurement points to be used for the tests are presented in Table D.1 and the proposed placement is presented Figure D.1 and Figure D.2. For usable chamber space (see 5.2.2).

Table D.1 — Number of sensors and test devices required for the tests described in Annex D

	≤ 60 l	> 60 l to 200 l	> 200 l to 1 000 l	> 1 000 l
Chamber temperature test	T = 6	T = 11	T = 11 + additional 2 for each additional 100 l	T = NLT 26 The number of T required shall be established.
Empty Chamber Distribution test (no load)	T = 6 M = 5	T = 11 M = 10	T = 11 + additional 2 for each additional 100 l M = 10 + additional 2 for each additional 100 l	T = NLT 26 M = NLT 26 The number of T and M required shall be established.
Empty Chamber Penetration test (no load)	P = 2	P = 3	P = 4 + additional 1 for each additional 100 l	P = NLT 12 The number of P required shall be established.
Small load	T = 6 TLU = 5	T = 11 TLU = 10	T = 11 + additional 2 for each additional 100 l TLU = 10 + additional 2 for each additional 100 l	T = NLT 26 SLT = NLT 26 The number of T and M required shall be established.
Full Load (max load according to 11.4 and/or 5.2.2)	T = 6 M = 5 in the load	T = 11 M = 10 in the load	T = 11 + additional 2 for each additional 100 l M = 10 + additional 2 for each additional 100 l	T = NLT 26 M = NLT 26 The number of T and M required shall be established.
For each microbiological test, a growth positive control shall be used.
T = temperature probe (see B.4) TLU = test load unit (including biological indicator) (see C.2.1) P = Penetration Type Test Device with Biological indicator (see B.7.5) NLT = not less than
Small Load: one test load unit (see C.2.2) and if applicable one specific test item / set (see Table A.1) Full load: set up of defined max number of test load units (see C.2.3) and if applicable, max. number of specific test items / sets (see Table A.1)

NOTE It might be necessary to wear personal protective equipment during recovery of the biological
indicators to prevent exposure to residual hydrogen peroxide on surfaces or in the atmosphere. The
instructions accompanying the sterilizer will provide guidance on this.


a) chamber reference point < 60 l	b) chamber reference point 60 l to < 120 l

c) chamber reference point 200 l to 1 000 l

Key

M =	biological indicator test device or small load unit
T =	temperature sensor in the chamber reference point
P =	Penetration Type Test Device with Biological indicator (see B.7.2)

NOTE The diagram shown for 200 l to 1 000 l chambers represents the maximum number of test devices which would be used in a 1 000 l chamber. Smaller chambers would require fewer devices however the loading distribution pattern can be used as a reference.

Figure D.1 — Biological indicator and small load unit locations for conducting physical and microbiological performance test in cylindrical chambers


a) chamber reference point < 60 l	b) chamber reference point 60 l to < 200 l

c) chamber reference point 200 l to 1 000 l

Key

M =	biological indicator test device or small load unit
T =	temperature sensor in the chamber reference point
P =	Penetration Type Test Device with Biological indicator (see B.7)

Figure D.2 — Biological indicator and small load unit locations for conducting physical and microbiological performance test in rectangular chambers

1. Test procedures
  1. Chamber temperature test

D.2.1.1 The test is used to demonstrate that a cycle start cannot be commenced unless inside surface temperatures of the chamber (including the doors) are within its pre-set temperature range.

D.2.1.2 The number of temperature sensors required for the test shall dependent upon the usable chamber space. Introduce the number of temperature sensors specified in Table D.1 using the test connection as specified in 5.2.5, or respectively place the data logger(s) into the chamber. Distribute the sensors specified in Table D.1 evenly on representative inner chamber surfaces specified for the sterilizer [see 11.5 and/or Figures D.1 and D.2)].

D.2.1.3 Carry out the measurements in an empty chamber.

D.2.1.4 Check for compliance with performance requirements in 5.2.4 after completion.

- 1. Microbiological empty chamber distribution test

D.2.2.1 This test is used to demonstrate that sterilant supply, temperatures, and pressure conditions versus time within the usable chamber space are such that recovery of test organisms from biological indicators placed in the test usable chamber space cannot be obtained after successful application of a reduced cycle in accordance with 10.3.2.

D.2.2.2 Prepare a number of biological indicators in accordance with B.7.5.3. The number of BI´s to be used are specified in Table D.1. Each biological indicator shall be enclosed within two layers of a sterile barrier system as specified in B.8 and as specified for the operation of the sterilizer (in accordance with Annex J).

D.2.2.3 The packaged biological indicators, excluding the positive controls, shall be distributed within the chamber as shown in Figure D.1 (cylindrical usable chamber space configuration) or Figure D.2 (parallelepiped usable chamber space configuration).

D.2.2.4 The sterilization cycle under test shall be immediately started. After completion of the cycle the visual display shall be checked to ensure that a cycle complete indication is visible. The chamber contents shall be unloaded, and the biological indicators recovered.

D.2.2.5 Both the exposed and unexposed (growth positive control) biological indicators shall be incubated in accordance with the instructions supplied.

D.2.2.6 The positive for growth indicator shall show growth. The biological indicators exposed to the sterilization cycle shall show no growth.

- 1. Small load physical performance test

D.2.3.1 This test is primarily used to demonstrate that temperatures, pressures and the sterilant supplied to the process do not exceed the specified limit values throughout the complete sterilization cycle as required by 10.2. Secondly, the test shall verify the correlation between the cycle parameter(s) and the sterilizing agent in the usable chamber space as required by 10.2. Thirdly, the test shall verify that a dry load, as specified in 10.5 is achieved.

D.2.3.2 Connect the pressure recording instrument to the chamber using the test connection described in 5.2.5, or, respectively, place the data logger in the chamber.

D.2.3.3 Connect and activate the sterilant supply and concentration measurement system (see B.6).

D.2.3.4 Prepare a number of test load units in accordance with C.2.2. The numbers of test load units to be used are specified in Table D.1.

D.2.3.5 Prepare a number of temperature sensors in accordance with Table D.1. Insert the sensors into the chamber using the test connection described in 5.2.5, or, respectively, place the data logger in the chamber.

D.2.3.5.1 One temperature sensor shall be placed at the reference measurement point (see 10.2.1).

D.2.3.5.2 The remaining temperature sensors shall be placed within the usable chamber space in accordance with Figure D.1 or Figure D.2.

D.2.3.6 Place the test load units as defined in Figure D.1 or Figure D.2 in the usable chamber space of the chamber using the load support system of the sterilizer and considering the loading instructions specified for the sterilizer (see 11.4).

D.2.3.7 Immediately start the sterilization cycle to be tested. After completion of the cycle, check that a visual display of cycle complete is obtained before unloading the sterilizer.

D.2.3.8 Remove the load and inspect it for compliance with 10.4.

D.2.3.9 Examine the pressure and temperature records for compliance with the performance requirements given in 10.2.

- 1. Small load microbiological performance test

D.2.4.1 This test is used to demonstrate that sterilant supply, temperatures, and pressure conditions versus time within this load are such that recovery of test organisms from biological indicators placed in the test load cannot be obtained after successful application of a reduced cycle in accordance with 10.3.2.

D.2.4.2 Prepare a number of BI´s in accordance with B.7.5.3. The numbers of BI’s to be used are specified in Table D.1. Each biological indicator shall be enclosed within two layers of a sterile barrier system as specified in B.8 and as specified for the operation of the sterilizer (see Annex J).

D.2.4.3 Distribute the test load units as defined in Figure D.1 or Figure D.2 in the usable space of the chamber using the load support system of the sterilizer and considering the loading instructions specified for the sterilizer (see 11.4).

D.2.4.4 The biological indicators, excluding the positive controls, shall be distributed within the chamber as shown in Figure D.1 (cylindrical usable chamber space configuration) or Figure D.2 (parallelepiped usable chamber space configuration).

D.2.4.5 Immediately start the sterilization cycle to be tested. After completion of the cycle, check that a visual display of cycle complete is obtained before unloading the sterilizer.

D.2.4.6 Remove the biological indicators and recover and incubate in accordance with the instructions supplied.

D.2.4.7 The positive for growth indicator shall show growth. The biological indicators exposed to the sterilization cycle shall show no growth.

- 1. Full load physical performance test

D.2.5.1 This demonstrates that temperatures, pressures and the sterilant supplied to the process do not exceed the specified limit values throughout the complete sterilization cycle as required by 10.2.

Secondly, the test shall verify the correlation between the cycle parameter(s) and the sterilizing agent in the usable chamber space as required by 10.2. Thirdly, the test shall verify that a dry load, as specified in 10.5 is achieved.

D.2.5.2 Connect the pressure recording instrument to the chamber using the test connection described in 5.2.5, or, respectively, place the data logger into the chamber.

D.2.5.3 Connect and activate the sterilant supply and concentration measurement system (see B.6).

D.2.5.4 Prepare a number of test load units, and additional load, in accordance with C.2.1.

D.2.5.5 Prepare a number of temperature sensors in accordance with Table D.1. Insert the sensors into the chamber using the test connection described in 5.2.5, or, respectively, place the data logger in the chamber.

D.2.5.5.1 One temperature sensor shall be placed at the reference measurement point (see 10.2.1).

D.2.5.5.2 Insert the remaining temperature sensors into sets of items C.2.1 a), b) and c) by piercing the sterile barrier systems. Use adhesive tape to fix the sensors in good thermal contact with the screws inside the sterile barrier systems and seal the sensor perforations of both sterile barrier systems. Seal the double sterile barrier systems and return the sets of items into the full load.

D.2.5.6 Distribute the test load units, and additional load, into the usable chamber space of the chamber considering Figure D.1, using the load support system of the sterilizer and considering the loading instructions specified for the sterilizer (see 11.5).

D.2.5.7 Immediately start the sterilization cycle to be tested. After completion of the cycle, check that a visual display of cycle complete is obtained before unloading the sterilizer.

D.2.5.8 Remove the load and inspect it for compliance with 10.4.

D.2.5.9 Examine the pressure and temperature records for compliance with the performance requirements given in 10.2.

- 1. Full load microbiological performance test

D.2.6.1 This test is used to demonstrate that sterilant supply, temperatures, and pressure conditions versus time within this load are such that recovery of test organisms from biological indicators placed in the test load cannot be obtained after successful application of a reduced cycle in accordance with 10.3.2.

D.2.6.2 Prepare a number of BI´s in accordance with B.7.5.3. The numbers of BI’s to be used are specified in Table D.1. Each biological indicator shall be enclosed within two layers of a sterile barrier system as specified in B.8 and as specified for the operation of the sterilizer.

D.2.6.3 Prepare a number of test load units, and additional load, in accordance with C.2.

D.2.6.4 The biological indicators, excluding the positive controls, shall be distributed within the chamber as shown in Figure D.1 (cylindrical usable chamber space configuration) or Figure D.2 (parallelepiped usable chamber space configuration).

D.2.6.5 Immediately start the sterilization cycle to be tested. After completion of the cycle, check that a visual display of cycle complete is obtained before unloading the sterilizer.

D.2.6.6 Remove the biological indicators and recover and incubate in accordance with the instructions supplied.

D.2.6.7 The positive for growth indicator shall show growth. The biological indicators exposed to the sterilization cycle shall show no growth.

- 1. Penetration performance test with PTTD

D.2.7.1 The penetration performance tests is intended to show that when the physical and chemical (sterilant) conditions during cycle profile tests (physical performance tests, see above) have been
demonstrated to fulfil the minimum penetration performance requirements of this document, recovery of test organisms from biological indicators placed in the PTTD cannot be obtained after successful application of a complete sterilization cycle.

NOTE The penetration performance tests does not demonstrate the capability of achieving a sterilization inside the lumen of the PTTD. Sterilization and SAL are demonstrated using reduced cycle concept. Higher penetration performance (for example real lumen load) are developed and tested according to ISO 22441:2022.

D.2.7.2 The number of PTTDs with biological indicators to be used in the empty chamber penetration tests test will depend on the loading capacity of the useable space. The number of PTTDs specified in Table D.1 shall be used and will be sufficient to ensure the homogeneity of the sterilant within the usable chamber space in terms of microbicidal lethality.

D.2.7.3 Biological indicators as defined in B.7.5 shall be used inside the PTTD to evaluate the microbicidal lethality achieved upon completion of the test. Each PTTD with biological indicator shall be used without a sterile barrier system.

D.2.7.4 The PTTD with biological indicators, excluding the positive controls, shall be distributed within the chamber as shown in Figure D.1 (cylindrical usable chamber space configuration) or Figure D.2 (parallelepiped usable chamber space configuration).

D.2.7.5 The PTTD with biological indicators shall remain inside the preheated chamber for temperature equilibration for 2 h, before starting the sterilization cycle under test. After completion of the cycle the visual display shall be checked to ensure that a cycle complete indication is visible. The chamber contents shall be unloaded, and the biological indicators recovered.

D.2.7.6 Both the exposed and unexposed (growth positive control) biological indicators shall be incubated in accordance with the instructions supplied.

D.2.7.7 The growth positive indicator shall show growth. The biological indicators exposed to the sterilization cycle shall show no growth.

- 1. Air Leakage test

D.2.8.1 The automatic test cycle as required by 6.2 is intended to display the rate of pressure rise caused by air leakage. After evacuation of the chamber at the lowest vacuum switch point specified for the conditioning stage, all connecting valves to the chamber shall be closed and a pressure stabilizing time of at least 5 min, but not exceeding 15 min shall precede the test period. The pressure change when measured over a period of 10 min shall not exceed the value specified in 6.2.6. There shall be a visual and/or audible indication if the test fails.

D.2.8.2 The maximum allowed error in measurement for a pressure difference is specified in 6.5.3.2.3.

- 1. Load dryness test

D.2.9.1 The load dryness test is used to demonstrate that the sterilization cycle is able to yield loads that do not show the presence of visible moisture after processing.

NOTE The load dryness tests can be carried out as an integrated part of the small and full load physical performance tests according to Table A.1.

D.2.9.2 Inspect the sterilized load and check for compliance with 10.5.

(informative)

Measurement of hydrogen peroxide
1. General

For applications within the scope of this document several measurement principles and commercially available instruments are described in the literature and can be used to measure the concentration or partial pressure of H₂O₂ in liquids or in gases. The different methods like chemical reaction of suctioned gaseous or liquid probes followed by spectroscopic analysis, or gas measurement systems like electro-chemical sensors, mass spectrometry, gas chromatography, infrared absorption, etc. have specific advantages and disadvantages. Some of them need specific laboratory operating facilities, are using sophisticated evaluation procedures or require scientific skill of the operators.

1. H₂O₂ in liquids
  1. Selection of test method

For determination of H₂O₂ in liquids several methods, e.g. titration and spectrophotometric measurement as well as fluorescence and chemo luminescence spectroscopy are established. The given titration methods have low accuracy at low concentrations.

A suitable validated method should be used.

Reaction with horseradish peroxidase seems to be the most widely used fluorescence method, which has an appropriately low working range (10⁻⁸ mg/ml to10⁻⁵ mg/ml) ([71], Clause 7). However, it takes place in acid solutions and therefore the sample solutions have to be buffered. Unfortunately, the buffer solution influences the intensity of fluorescence [68].

From the different known spectrophotometric methods, the measurement of VH2O2 via a titanium (IV)-peroxo complex seems most suitable to be used for intended tests. The working range with standard laboratory equipment is at 0,1 mg/l to 50 mg/l ([71], Clause 7) and therefore covers the region of interest. If necessary, it can easily be scaled down to 2 μg/ml to 20 μg/ml [53]. Furthermore this method generates a stable complex that is not sensitive to light and the occurring reaction is specific to H₂O₂ and therefore not influenced by other oxidizing substances.

NOTE This method has frequently been used, e.g. from the US Environmental Protection Agency [71], and titanium (IV) reagents are described as the favoured reagents for bubbler samples in a European Union Risk Assessment Report to measure airborne concentrations [62].

Methods for determination of H₂O₂ in liquids can also be used as well for measurement of adsorbed H₂O₂ residuals on processed items by immersion of a defined test sample of this item or the complete item itself into a specific extraction reagent in order to transfer the adsorbed H₂O₂ into the solution for further analysis.

Consequently, spectrophotometric measurement of VH2O2 via a titanium (IV)-peroxo complex is one of the recommended methods for determination of H₂O₂ residuals.

- 1. Spectrometric analysis of H₂O₂ contents in liquids
    1. Equipment

E.2.2.1.1 Ti (IV) reagent:

1) concentrate of absorption solution:

Dissolve 20 g potassium titanium oxide oxalate-2-dihydrate (C₄K₉O₂Ti × 2H₂O) and 30 g oxalic acid (C₂H₂O₄) in 800 ml distilled water by heating. Allow to cool to room temperature and fill to 1 000 ml using deionised water. The solution is durable for 1 year at room temperature.

2) absorption solution:

Take 50 ml of the stock solution and fill it up to 1 000 ml with distilled water. The solution is durable for 4 weeks at room temperature.

E.2.2.1.2 Spectrophotometer at a wavelength of 385 nm to 420 nm (used at the absorption maximum) and 10 mm/50 mm glass cuvettes.

E.2.2.1.3 Erlenmeyer flasks (50 ml) with glass stopper.

E.2.2.1.4 H₂O₂ solution with a well-known concentration about 30 % (used for calibration).

E.2.2.1.5 Permanganate or iodide solution to verify the concentration of the H₂O₂ stock solution as specified in E.2.2.2.2 a) 1) via titration.

NOTE 1 Regulations and environmental effects of the disposal of used chemicals and indicators are subjects to be investigated and planned prior to use.

NOTE 2 Attention is drawn to necessary precautionary measures when handling chemicals that can be dangerous to persons or environment.

- - 1. Calibration

E.2.2.2.1 The calibration procedure is used to establish a diagram for transforming the spectrophotometer readings directly into a quantity of H₂O₂ expressed as microgram (μg) per indicator.

A H₂O₂ solution with a known concentration of H₂O₂ forms the basis of the calibration. This solution is diluted into several ratios to form samples with less concentration, which is determined very precisely. After performing a calibration procedure as described in E.2.2.2.2 a diagram is produced establishing the relationship of the parameter microgram (μg) H₂O₂ against the absorption value of the spectrophotometer (i.e. a calibration curve). This diagram is used to determine the H₂O₂ quantity which can be directly read off or calculated by means of the inclined line of the graph.

The calibration procedure described by Breuer et al. [53] can be used for concentrations down to 50 μg/25 ml thru 500 μg/25 ml, equivalent to 2 μg/ml thru 20 μg/ml. Therefore, it is appropriate for the calibration of the concentration ranges of interest.

E.2.2.2.2 Calibration can be performed using the following procedure:

a) Prepare a series of 11 samples with different H₂O₂ concentrations as follows:

1) Stock solution (ca. 10 mg/ml): Take 3,3 g of the H₂O₂ solution (30 %) and add adsorption solution to 100 ml. The precise concentration has to be verified by permanganate or iodometric titration;

2) Standard solution (ca. 100 µg/ml): Pipette 1 ml of the H₂O₂ stock solution into 100 ml graduated flasks and add absorption solution to 100 ml;

3) Calibration solutions: Pipette 0,5 ml; 1,0 ml; 1,5 ml; 2,0 ml; 2,5 ml; 3,0 ml; 3,5 ml; 4,0 ml; 4,5 ml; 5,0 ml in 25 ml graduated flasks and add absorption solution to 25 ml. Allow the solutions to stand for about 5 min.

b) To increase measurement reliability, repeat steps 1) to 3) to produce a parallel set of identical solutions; two sets of calibrated samples designed for spectrophotometer analysis that are representing 0 μg, and 50 μg H₂O₂ to 500 μg H₂O₂ dissolved in 25,0 ml solution are hereby established.

c) Establish a diagram with one axis representing spectrometer readings and the other axis representing microgram H₂O₂ per 25 ml of solution. Re-scaling of this axis would allow reading the values directly in µg/ml.

d) Measure the absorption of each of the 11 samples of the 2 sets at a wavelength of 385 nm to 420 nm using the spectrophotometer. Take the values measured and their known relationship to the H₂O₂ contents per 25 ml of solution and generate a calibration diagram. By application of the minimal square method (linear regression) an arithmetic mean straight line can be generated. Insert two straight lines into the diagram, representing the maximum and the minimum deviation of the slope of the line.

NOTE The minimal square method or linear regression is an established mathematical method used to minimize the sum of deviations of measured values if a straight line can be assumed to result.

- - 1. Operation

The calibration diagram can be used to determine the total H₂O₂ contents in μg per 25 ml of solution (or in µg/ml, if re-scaled) directly as a function of the measured spectrophotometer absorption value at 385 nm to 420 nm.

Measurement of gaseous H₂O₂ residues from specific desorption test sets can be performed using this analysis method after suctioning and bubbling an extracted gas probe from the calibrated desorption test device (see B.7) through the extraction reagent described in E.2.2.1.1 b).

1. H₂O₂ in gaseous compositions
  1. General

Besides using the methods for determination of H₂O₂ in liquids as described in E.2, direct measurement methods of gaseous H₂O₂ as mentioned in E.1 are available.

- 1. Selection of measurement method

E.3.2.1 Mass spectrometric systems are providing specific relative signals for all molecules, their different fractions and even single atoms contained in a mixture of gases, differentiated by their atomic masses. By complex analysis, based on empirically gained databases and with reference to the (measured) total pressure, the concentration of each individual gas component can be measured. Mass spectrometers need high vacuum conditions and a higher level of operator's qualification which restrict their use to laboratory applications in most cases.

E.3.2.2 In gas chromatography (GC) a gaseous sample is suctioned from the atmosphere to be analysed, injected into a continuous flow of a specific carrier gas (e.g. helium or nitrogen), and directed into a fractionating column. This column causes each compound of the gas mixture to elute at different specific retention times. Arrival of each compound at the end of the column can be detected by suitable sensors. The separation capability of a gas chromatography is significantly linked to the length of the fractionating column; however, microsystems using semiconductor channel arrays are available which allow mobile operation of such systems. Gas chromatography need calibration and sophisticated computerized evaluation algorithms to allow quantitative analysis of specific gases. H₂O₂ can cause damaging chemical reactions with the material used for the columns.

E.3.2.3 Infrared (IR) absorption spectroscopy uses the specific high absorption capability of specific inner molecular bonds for defined infrared wavelengths if light from a suitable source is transmitted through a gas probe. The sensitivity and selectivity of the system depend on the selection of one or more (intermittent) specific wavelengths and the length of the transmission path. Both can be significantly improved by multi-reflection arrays and application of modulation techniques. As being an optical system, the emitter-sensor system is sensitive to condensation and in many cases requires heated windows or lenses. Presently only few IR measurement systems for H₂O₂ are available in the market.

E.3.2.4 Electrochemical sensors contain two or more electrodes in contact with an electrolyte. The electrodes are typically built up by fixing a high surface area precious metal on to the porous hydrophobic membrane. The working electrode contacts both the electrolyte and the ambient atmosphere to be monitored usually via a porous membrane. The electrolyte most commonly used is an inorganic or organic acid, and by oxidation an electrical potential is generated, in many cases proportional to the gas concentration. Specific combinations of the electrodes, catalysts and the electrolyte reduce cross-sensitivity for other gases and allow differentiation of defined gas components. The electrodes and the electrolyte are usually contained in a plastic housing, which commonly comprises electronic components for signal conversion and transmission. Gas measurement systems using electrochemical sensors are cheap, compared to the other mentioned methods, can be provided as hand-held instruments, and are easy to use. Critically to be considered in particular for H₂O₂ measurement is the calibration and the long-term stability of the signal.

Based on the available information as provided above and the characteristics of the different methods the use of electro chemical sensors is considered here as a suitable method for H₂O₂ gas measurement. It can be used for process control, monitoring, and recording. It can be used as well for determination of H₂O₂ residuals, as an alternative to the method described in E.2 following the procedure described in B.7.

- 1. Measurement of gaseous H2O2 using electro chemical sensors

Various electrochemical sensors for measuring H₂O₂ and necessary electronic equipment for evaluation and output of the measurement result are available in the market. Care shall be taken to avoid excessive operating pressure differences between the outside of the porous membrane and the outside of the sensor case, which could adversely affect calibration and lifetime.

- 1. Calibration and operation

For calibration and operation of the measurement systems the user instructions should be followed. Calibration of electrochemical sensors requires specific know how and suitable laboratory facilities.

(normative)

Efficacy of H₂O₂ removal
1. H₂O₂ in ambient air
  1. Purpose of test

The purpose of the test is to verify that the concentration of H₂O₂ complies with 8.3.2.

- 1. Test scope

The test environment shall be adapted to the design and intended use of the sterilizer.

Tests shall be performed with the following test conditions:

a) Empty chamber; The sterilizer door is opened immediately after end of cycle.

b) A representative full load (see also C.2.3), including packaging, as specified for the sterilizer and with the lowest recommended temperature. The door is opened at the least favourable time after end of cycle.

In all tests the measurements shall be logged from start of the cycle until at least 30 min after door opening.

The environmental conditions shall be in accordance with EN 61010‑1:2010, 4.3.1.

The sterilant used at the test shall conform with the specification in the user instructions.

All sterilization cycles administering H₂O₂ into the chamber shall be tested.

- 1. Instrumentation

A test instrument capable of measuring VH2O2 in air with a resolution of at least 0,14 mg/m³ (equivalent to 0,1 ppmV) and a measurement range at least in the range 0,14 mg/m³ (0,1 ppmV) thru 7 mg/m³ (5 ppmV) shall be used. The instrument shall be placed in front of the sterilizer at a distance of 1 m and at a height of 1,7 m (as specified by EN IEC 61010‑2‑040:2021). The instrumentation shall be capable to log the measured value at least every second.

- 1. Acceptance criteria

The evaluation of the measured concentration of H₂O₂ in air shall comply with 8.3.1.

1. Liquid H₂O₂ on load
  1. Purpose of test

The purpose of the test is to verify that there is no liquid H₂O₂ on the surface of the load that could produce risks for the operator handling the load.

- 1. Test scope

A representative full load, including wrapping, as specified by the manufacturer and with the lowest recommended temperature shall be placed in the chamber and the process shall be started without delay.

Immediately after completion of the operating cycle, the door shall be opened, and the load removed. The external surface of the load shall be inspected for visual evidence of liquid droplets. The load shall then be disassembled and further inspected for visual evidence of liquid droplets in any part of the load.

- 1. Acceptance criteria

Wet spots and droplets shall not be visible on the load.

(informative)

Additional information on protective measures

Annex G provides additional information regarding the protective measures specified in 5.1.2, which should be considered for development and testing, if applicable:

a) For Marking [see 5.1.2.2 a) of this document], EN 60204‑1:2018 Clause 16 can provide additional details regarding the design and positioning of the marking.

b) For the protection against hazards of an electrical nature including electric shock [see 5.1.2.2 b) of this document], EN 60204‑1:2018, Clause 4 to Clause 8, Clause 12, Clause 13 and Annex A can provide additional guidance.

c) For the protection against mechanical hazards related to mechanical functions [see 5.1.2.2 c), d) and k) of this document], EN ISO 12100:2010, 6.2.2.1, 6.2.6, 6.3.3.1, applicable parts of 6.3.3.2 and EN 60204‑1:2018, Clause 9 and Clause 10 can provide additional guidance.

d) For the protection against hazards related to the spread of fire and resistance to heat [see 5.1.2.2 e) of this document], EN 60204‑1:2018, 6.3.3, 6.4 and Clause 7 can provide additional guidance.

e) For the protection against burn and scald hazards [see 5.1.2.2 f) of this document], EN 60204‑1:2018, 6.3.3, 6.4 and Clause 7 and EN ISO 13732‑1 can provide additional guidance.

f) For the protection against hazards related to components and subassemblies [See 5.1.2.2 i) of this document], EN 60204‑1:2018, Clause 14 and Clause 15 and EN ISO 12100:2010, Clause 6 can provide additional guidance.

g) For the protection against hazards resulting from failures of software for software-controlled devices related to safety of the sterilizer and ancillary equipment operation or process control [see 5.1.2.2 i)], EN 61508 series, EN 62304:2006, EN IEC 62061:2021, EN ISO 13849‑1:2023, and EN ISO 13849‑2:2012 can provide additional guidance.

h) For the protection against hazards resulting from application (misuse, ergonomic aspects) [see 5.1.3 of this document], EN ISO 12100:2010, 6.2.8 can provide additional guidance.

(informative)

Environmental aspects
1. Environmental aspects regarding the life cycle of VH2O2 sterilizers - General Environmental aspects

The environmental aspects addressed by this document are related to the development, installation, validation, and operation of the sterilizer during the entire life cycle. Factors such as operating frequency, load capacity and configuration can have a significant outcome on the environmental aspects of operation of the process. During the development, installation, validation and operation of low temperature vaporized hydrogen peroxide sterilization processes, the environmental aspects can be summarized as follows:

a) installation and final disposal of the sterilizer and ancillary equipment;

b) emissions to air of hydrogen peroxide and its reaction products;

c) contamination of processed items by residues;

d) use and disposal of raw materials for operation such a sterile barrier system, biological or chemical indicators;

NOTE 1 Annex D of EN ISO 11607‑1:2020 provides guidance on environmental aspects of sterile barrier system and packaging systems.

e) Energy consumption such as electricity use.

NOTE 2 Some of these environmental aspects are related to the sterilizer design and performance (e.g. tightness of system components containing process chemicals, performance regarding desorption of hydrogen peroxide and its reaction products), hence are considered in the respective sterilizer specifications. Therefore, the sterilizer operation has an overall impact on the environment.

NOTE 3 Occupational safety and health requirements are matter for regional or national legislation, hence are not specified in this document.

The potential effect on environment of any substance which could be released, either deliberately or accidentally. During or following use of the sterilizing agent, shall be assessed and measured for the control of the established substance (in this case VH2O2). This assessment including the potential effect (if any) and the measures for control (if identified), shall be recorded.

1. Hydrogen peroxide
  1. General

Hydrogen peroxide (H₂O₂) is a very pale blue liquid at room temperature which appears colourless in a dilute solution, slightly more viscous than water.

Small amounts of gaseous hydrogen peroxide occur naturally in the air. Hydrogen peroxide is unstable, decomposing readily to oxygen and water with release of heat. Although non-flammable, it is a powerful oxidizing agent that can cause spontaneous combustion when it comes in contact with organic material.

- 1. Physico-Chemical properties

Some physical and chemical properties of hydrogen peroxide solutions are given in the Table H.1.

Table H.1 — Physico-Chemical properties of H₂O₂

H₂O₂	35 % w/w	50 % w/w	70 % w/w	90 % w/w
Melting point	−33°C	−52°C	−40°C	−11°C
Boiling point	108°C	114°C	125°C	141°C
Density (g/cm³ at 25°C)	1,1282	1,1914	1,2839	1,3867
Vapour pressure (partial) at 30°C	48 Pa	99 Pa	200 Pa	-
Vapour pressure (total) at 30°C	-	2,4 kPa	1,47 kPa	0,67 kPa
Saturated vapour concentration at 25°C	-	787 mg/m³	1,685 mg/m³	3,049 mg/m³
NOTE Data taken from Table 1.2 in “European Union Risk Assessment Report Hydrogen Peroxide”, Office for Official Publications of the European Communities, Final Report, 2003, CAS No: 7722–84–1, EINECS No: 231–765–0 [63].

- 1. Classification criteria and labelling requirements

Classification criteria and labelling requirements for dangerous substances are specified by the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS) incorporated into the European Regulation (EC) No 1272/2008 on classification labelling and packaging of substances and mixtures (CLP Regulation). In accordance with Annex VI, part 3, Table 3.1 of the CLP Regulation hydrogen peroxide solutions (CAS No 7722-84-1) within the application range as being relevant for VH2O2 sterilization are classified as given in Table H.2.

Table H.2 — EC Regulation classifications of hydrogen peroxide-water solutions

Hazard class	Specific concentration limits	Hazard category	Hazard statement
Oxidising liquid	50 % ≤ C < 70 %	2	H272 can intensify fire; oxidizer
Skin corrosion	50 % ≤ C < 70 %	1B	H314 causes severe skin burns and eye damage
Skin irritation	35 % ≤ C < 50 %	2	H315 causes skin irritation
Eye damage	50 % ≤ C < 70 %	1B	H314 causes severe skin burns and eye damage
Specific target organ toxicity (STOT)	C ≥ 35 %	SE3	H335 can cause respiratory irritation
Acute toxicity (oral)	C ≥ 50 %	4	H302 harmful if swallowed
Acute toxicity (inhalation)	C ≥ 50 %	4	H332 harmful if inhaled

1. Environmental impact

Attention is drawn to the possible existence in some countries of regulations giving safety requirement for handling H₂O₂ and for premises in which it is used.

The environmental impact generated during testing and normal use by a sterilizer delivering a VH2O2 sterilization process is mainly due to:

— the design and selection of materials;

— preproduction activities that use energy and other services;

— the manufacture of the sterilizer including the use of material resources, energy and consumables;

— packaging, transportation and installation;

— maintenance activities including the extent of repair, testing, inspections, cleaning and the use of protecting and cleaning agents;

— the treatment of the feed water and the consumption of energy;

— the consumption of electricity, compressed air, H₂O₂ and other resources for operational and cooling purposes;

NOTE Minimizing their use reduces emissions and can increase the durability and life of the sterilizer.

— the disposal or recovery of waste;

— the release of fluids and substances;

— chemical reactions (e.g. corrosion, deterioration) at the processed products;

— the generation of noise, vibration and radiation;

— heat emission to the working environment;

— the scrapping of the sterilizer and ancillary equipment at the end of its life cycle and the recycling of materials.

To highlight the importance of reducing the environmental burden, these European Standard addresses requirements or recommendations intended to decrease environmental impact caused by those aspects during different stages of the sterilizer life cycle, see Table H.1.

Therefore, the potential effect (as listed above) on the environment of the operation of the sterilization process together with the relevant hazard classifications should be assessed and measures to protect the environment should be identified. The assessment, including potential impact and measures for control should be documented.

Users of H₂O₂ are reminded to comply with applicable local, national and international requirements regarding its emission and disposal. Planning of the activities described in this document can help to minimize the environmental aspects.

Table H.3 shows how clauses of this document address requirements or recommendations indented to decrease the environmental impact of operation of a VH2O2 sterilization process.

Table H.3 — Environmental aspects addressing clauses of this document

Environmental aspects (Inputs and Outputs)		Product life — cycle
		Production and reproduction	Distribution (including packaging)	Use	End of life
		Stage A^a	Stage B^a	Stage C	Stage D
		addressed	addressed	addressed	addressed
1	Resource use	Clause 4 Clause 6 Clause 8 Clause 9 Clause 10	Clause 4 Clause 6 Clause 8 Clause 9 Clause 10	Clause 4 Clause 6 Clause 8 Clause 9 Clause 10	Clause 10
2	Energy consumption	Clause 11	Clause 11	Clause 11
3	Emission to air	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11	Clause 4 Clause 8 Clause 11	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11
4	Emission to water	Clause 4 Clause 5 Clause 6 Clause 8 Clause 11	Clause 4 Clause 8 Clause 11	Clause 4 Clause 5 Clause 6 Clause 8 Clause 11
5	Waste	Clause 7 Clause 8 Clause 10 Clause 11	Clause 8 Clause 11	Clause 7 Clause 8 Clause 10 Clause 11	Clause 10
6	Noise	Clause 8 Clause 10	Clause 8	Clause 8 Clause 10
7	Migration of hazardous substances	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11	Clause 4 Clause 8 Clause 11	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11
8	Impacts on soil	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11	Clause 4 Clause 8 Clause 11	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11
9	Risks to the environment from accidents or misuse	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11	Clause 4 Clause 8 Clause 11	Clause 4 Clause 5 Clause 6 Clause 7 Clause 8 Clause 11
^a Several common references in stages A and C above are made regarding testing as testing procedures are requested by this document during both stages of the life cycle (see test programme in Annex B).

Users of H₂O₂ are reminded to comply with applicable local, national and international requirements regarding its emission and disposal.

(informative)

Illustrations of the interrelationship between control and recording
1. Introduction

This informative Annex provides examples of configurations of the relationships between control and recording of a sterilizer to illustrate potential approaches to conforming with Clause 6.

In developing the illustrations, the following criteria were identified as relevant:

a) adequately reflecting the state of the art and the concept for “independent recording” of the process data, as established in current equipment standards for reprocessing of medical devices;

b) not being design restrictive, independent of its informative character;

c) not superseding published sterilizer standards requirements;

d) providing consistency in its details with the requirements given in the normative text;

e) consistently using the terminology as defined in Clause 3 and by EN ISO 11139.

For better understanding of the overall concept, it is important to recognize some relevant definitions and basic requirements:

Control is defined as “regulation of variables within specified limits” which is understood to be performed by “controllers”.

A sterilizer control system can comprise several different controllers for different functions, or combinations thereof, operated by segregated software modules, e.g.

— Cycle controller to control the operating cycle by use of set-values for cycle parameters (including tolerances) from the cycle specifications and to operate actuators (e.g. valves, evacuation pumps, injection systems for process media) in a programmed automatic sequence through the cycle stages. Measurement signals from the cycle controller measuring chains can feedback information about the current values of the resulting cycle variables in the chamber to the cycle controller in order to allow comparison with the set-values and re-adjustment of the cycle control in case of deviations (closed-loop control).

— User interface controller to allow pre-set values for the cycle control to be adjusted (e.g. by cycle selection, application of options), indication of set values (cycles, parameters), indication of measured values e.g. from cycle control and from independent data collection, indications from the failure detection system (e.g. deviation of measured values from set-values, indications from supply media failures, indication of any other failure of hardware components of the sterilizer)

— Data processing controller to collect the raw data from sensors, actuators, and any other controller to store them in the data retention module, to convert them into physical properties for indication or to direct them on demand to output systems (recorders, printers).

— Independent data collection system to direct cycle parameters measured by separate measuring chains, independently from the cycle controller to the data retention system and to the failure detection system for evaluation, display or recording/printing.

— Controllers to operate recorders or printers using data from the data retention system, convert them into readable output format (e.g. physical parameters, scaling, text information), and display them in digital or analogue format.

— Failure detection system to collect defined data, to evaluate and classify them following a sophisticated interpretation algorithm with regard their implications (results from risk analysis) and to initiate respective cycle control interventions, messages and recordings.

— Interface controller to allow remote control of the sterilizer or remote service maintenance activities via internet.

All controllers comprise individual timers which shall be synchronized with real time.

Different controllers and control functions can be separate or combined in one module. They can be arranged physically on one or more interconnected PLCs and are operated by software modules which are segregated or not, depending on the results of the risk analysis regarding their functions.

Monitoring is defined as “continual checking, supervising, critically observing, or determining the status, in order to identify change from the performance level required or expected”.

Following this definition, the monitoring system as used in this document, is understood as evaluation of a combination of functions and information provided by the different controllers used in the control and monitoring system (see following illustrations) regarding their functional implications and eventually necessary corrective measures.

The term “monitoring” should not be mixed with the interpretation of the term “monitor”, which is different in character and used to describe a device to measure and display one or more physical variables or to indicate the status of a functional component.

Independence (not defined in EN ISO 11139:2018)

The term independence is used in this document to describe an essential requirement for recording, established for medical devices reprocessing equipment (see e.g. 6.2.2), which is expressed e.g. as

“Means shall be provided to ensure that a failure in a control function does not lead to a failure in recording of process parameters such that an ineffective process appears effective.”

In practice this is mostly achieved by independent measuring chains (hardware components) for process control and for recording. For further evaluation of the output data of the measuring chains (conversion into scaled physical characteristics for display and recording, comparison with cycle specifications and pre-set cycle control parameters), segregated software modules should be used and separately validated.

It should be noted that the often-used term “independent monitoring” is misunderstanding and not applicable in the sense as used in this standard. Since the monitoring (system) is collecting and evaluating inputs from many different controller systems and components of the sterilizer, including the cycle control parameters (see above), it cannot be independent from cycle control.

NOTE The following illustrations are prepared by different expert groups for implementation as Annex B into ISO/TS 22421:2021, and not yet harmonized. In some cases, not all criteria identified as relevant for preparation of the illustrations (see above) are consistently being considered. Relevant for proper implementation of these concepts are the requirements given in the normative part of this document. It is intended to revise this Annex at the next revision.

1. Illustration 1

I.2.1 Figure I.1 provides the first example of a potential configuration of control and recording.

Figure I.1 — Illustration 1 of the interrelationship between control and recording [Source: ISO/TS 22421:2021, Figure B.1]

I.2.2 Figure I.1 is guided by some basics which are considered essential and helpful for understanding of the monitoring and control concept as laid down in several Clauses of this document.

The understanding of “independent monitoring” diverges between different experts. It might be helpful to differentiate between:

a) Monitoring systems for high-risk applications, which require full (or multiple) redundancy of the complete control and monitoring systems (mirroring), combined with a sophisticated process evaluation and supervising system (e.g. “watch dog”), which allows immediate fault detection, alarms, and eventually automated corrective actions for continued (non-interrupted) basic operation. Such systems are typically used in e.g. life support systems in medical intensive care units or in space applications.

b) Monitoring systems providing redundant measurement of essential parameters using independent monitors (measuring chains) for control and recording of essential process parameters, combined as well with a process evaluation and supervising system (e.g. “watch dog”), which allows fault detection and alarms, followed, if applicable, by a controlled reset of the system into a safe status and allows proper documentation of all details for later evaluation and consideration.

I.2.3 Consequently, the concept:

a) distinguishes between cycle control, data processing and the user interfaces (controls, indication, recording and printing);

b) has a focus on processes (hardware or software), rather than on hardware components;

c) allows flexible separation of cycle control from redundant data collection and processing, independent from the design several modules may exist;

d) has a focus on flows of information, which do not limit the implementation of the identical (redundant) functions but allows a specific segregation of functional modules and processes;

e) indicates an exchange of information between two “independent processes” and identification of unintended deviations helps minimizing risk. An example is the control of a sterilizer that may react to a deviation between the data sets of process control and independent reference measurements and ensures:

1) the measured difference should be detected as a failure;

2) the detected failure should be indicated and recorded;

3) the process control should be able to react to this deviation;

4) neither the process control nor an action at the control panel are able to modify the independent recording.

Modern software and hardware use concepts like “events” or “data tunnelling”, what is addressed by directed streams of information and a distinction between “Data flow” and “Control flow” (commands).

1. Illustration 2

I.3.1 Figure I.2 provides the second example of a potential configuration of control and recording.

Figure I.2 — Illustration 2 of the interrelationship between control and recording
[Source: ISO/TS 22421:2021, Figure B.2]

I.3.2 The above diagram is one illustration of the principles described below:

a) Means is provided to ensure that a failure or deviation of sterilization cycle control does not remain undetected and that a defective cycle does not appear effective. This is achieved by comparative analysis between data used for cycle control and independently acquired data. The comparison is performed for, at least, each process and cycle variable as defined by the sterilizer Manufacturer (for example, temperature of the chamber or load, Pressure in the chamber, time, concentration of sterilizing agent, etc.).

b) The means by which control and independent data are acquired may differ. For example, the temperature, pressure or sterilizing agent concentration data may be produced by different type of sensors and/or methods.

c) A/D conversion of cycle control data and independent monitoring data are segregated.

d) Processing of control data and independent data may be segregated or share common hardware or software module. In the second case, design avoids misleading interference between the two flows of data.

e) Failure detection by comparative analysis of cycle control data and independent data are performed automatically and/or by analysis of recorded, displayed or printed data by a certified operator.

f) Records of independent data, results of failure analysis and optionally control data are stored in accordance with local requirements.

1. Illustration 3
  1. Figure

Figure I.3 provides the third example of a potential configuration of control and recording.

Figure I.3 — Illustration 3 of the interrelationship between control and recording [Source: ISO/TS 22421:2021, Figure B.3]

- 1. Main objectives

Means is provided to ensure that a failure in a control function does not lead to a failure in recording of process parameters such that an ineffective process appears effective. This is achieved by the use of segregated systems and through failure detection that identifies any discrepancies and indicates a fault.

Independence can be achieved by physical or logical segregation and involve one or more microcontrollers. Modules can be divided into more submodules as long as they remain segregated from the other modules.

- 1. Control data processing system

The control data processing system are segregated from the independent data (see 6.3.2). This system receives data from sensors and AD-converters physically different from the independent sensors (see 6.3.1). The system converts the raw data to data scaled in engineering units and may include provisions for filtration, linearization, correction and calibration.

- 1. Independent data processing system

The independent data processing system is segregated from the control data (see 6.3.2). This system receives data from sensors and AD-converters physically different from the process control sensors (see 6.3.1). Cycle parameters and process parameters critical for process efficacy and safety are monitored. The system converts the raw data to data scaled in engineering units and may include provisions for filtration, linearization, correction and calibration.

- 1. Cycle control function

The cycle control function receives control data (see 6.3.3) and includes the main logics used to direct the equipment sequentially through required stages of the cycle in response to programmed cycle parameters. The control function operates valves, timers, PID-controllers and pumps, and make decisions at various positions during the cycle for example when parameters are reached, or timers have elapsed.

- 1. Means for failure detection

The system for failure detection is critical for the process efficacy or the safety. Failures are generated if the parameters differ from the specified conditions. This system receives both control and independent data (see 6.3.5).

- 1. Data retention module

The data retention module compiles and stores control and independent data and informative data for identification, time stamps, stage transition and notification of failures when they occur. Records are generated periodically, during stage transition and at extreme points in the process. The data are submitted for recording or printing. This module includes functionality for submittal at a later stage if data transfer to the recorder is temporary out of service.

- 1. Controls and indicating devices

User interfaces with controls and indicating devices are used for visible, audible and tactile interaction with operators to perceive and interact with the process. Indication can be shown as a physical property, e.g. temperature, pressure, time and concentration, or just as distinct information displayed as something being active, inactive, ready, open or closed. The user interfaces can be on the sterilizer or in a remote operating facility. Controls can be any button or switch including soft buttons on an operating panel. Faults are indicated and result in audible or visible alarms. Stop or automatic progression after faults can be decided by the control function (see B.3.4) or a result of interaction through indication and controls.

- 1. Recorder

Storage of process records from the data retention module described in B.3.6 can be directly with devices connected to the sterilizer, or remotely on a network drive (see 6.3.6). Process records may also be handled by an external SCADA system.

NOTE SCADA is supervisory control and data acquisition. SCADA is a collection of both software and hardware components that allow supervision and control of plants, both locally and remotely. This can include handling of goods flow in the health care premises locally or regionally.

- 1. Optional printer

Printing of process records can be directly with devices fitted on the sterilizer, or remotely on a network printer (see 6.3.7).

(informative)

Relationship between this European Standard and the General Safety and Performance Requirements of Regulation (EU) 2017/745 aimed to be covered

This European standard has been prepared under M/575 to provide one voluntary means of conforming to the General Safety and Performance Requirements of Regulation (EU) 2017/745 of 5 April 2017 concerning medical devices [OJ L 117] and to system or process requirements including those relating to quality management systems, risk management, post-market surveillance systems, clinical investigations, clinical evaluation or post-market clinical follow-up.

Once this standard is cited in the Official Journal of the European Union under that Regulation, compliance with the normative clauses of this standard given in Table ZA.1 confers, within the limits of the scope of this standard, a presumption of conformity with the corresponding General Safety and Performance Requirements of that Regulation, and associated EFTA Regulations.

Where a definition in this standard differs from a definition of the same term set out in Regulation (EU) 2017/745, the differences shall be indicated in this Annex ZA. For the purpose of using this standard in support of the requirements set out in Regulation (EU) 2017/745, the definitions set out in this Regulation prevail.

Where the European standard is an adoption of an International Standard, the scope of this standard can differ from the scope of the European Regulation that it supports. As the scope of the applicable regulatory requirements differ from nation to nation and region to region, the standard can only support European regulatory requirements to the extent of the scope of the European regulation for medical devices (EU) 2017/745).

NOTE 1 Where a reference from a clause of this standard to the risk management process is made, the risk management process needs to be in compliance with Regulation (EU) 2017/745. This means that risks have to be ‘reduced as far as possible’, ‘reduced to the lowest possible level’, ‘reduced as far as possible and appropriate’, ‘removed or reduced as far as possible’, ‘eliminated or reduced as far as possible’, ’removed or minimized as far as possible’, or ‘minimized’, according to the wording of the corresponding General Safety and Performance Requirement.

NOTE 2 The manufacturer’s policy for determining acceptable risk must be in compliance with General Safety and Performance Requirements 1, 2, 3, 4, 5, 8, 9, 10, 11, 14, 16, 17, 18, 19, 20, 21 and 22 of the Regulation.

NOTE 3 When a General Safety and Performance Requirement does not appear in Table ZA.1, it means that it is not addressed by this European Standard.

Table ZA.1 — Correspondence between this European standard and Annex I of Regulation (EU) 2017/745 [OJ L 117] and to system or process requirements including those relating to quality management systems, risk management, post-market surveillance systems, clinical investigations, clinical evaluation or post-market clinical follow-up

General Safety and Performance Requirements of Regulation (EU) 2017/745	Clause(s)/sub‐clause(s) of this EN	Remarks/Notes
10.1 (a)	5.2.1, 5.3.1.1	Covered with respect to the choice of materials in contact with hydrogen peroxide that are chosen not to be toxic or cause health hazard (5.2.1, 5.3.1.1).
10.1 (d)	5.2.1, 5.3.1.1	Covered with respect to choice of materials in contact with hydrogen peroxide (5.2.1, 5.3.1.1).
10.2	5.3.1.2, 8.3.1, 8.3.3, Annex F 2)	Covered with respect to the risk posed by contaminants from external sources (5.3.1.2) Covered with respect to the risk posed by visible liquid contaminants for the patient (8.3.1, 8.3.3 and Annex F 2)).
10.3	5.2.1	Covered with respect to choice of materials not deteriorating hydrogen peroxide and indirectly not the processed load (5.2.1).
10.5	7.1.4, 7.10	Covered with respect to particle ingress that could affect performance (7.1.4, 7.10).
10.6	7.10	Covered with respect to particles ingress that could contaminate the sterile device or be harmful to patient (7.10). Not covered for nanomaterials.
14.2 (a)	5.1.2.2 c), 5.1.2.2 d)	Covered with respect to material strength and resistance against fracture and fatigue (5.1.2.2 c), 5.1.2.2 d)).
14.2 (b)	5.1.2.4	Covered with respect to immunity to electromagnetic interferences (5.1.2.4).
14.2 (c)	5.2.1, 5.3.1.1, 7.10	Covered with respect to choice of materials not deteriorating hydrogen peroxide (5.2.1, 5.3.1.1). Covered with respect to contaminants in hydrogen peroxide during use (7.10)
14.2 (e)	5.3.1.1, 7.1.4, 7.10	Covered with respect to particle ingress that could affect safety (5.3.1.1, 7.1.4, 7.10)
14.3	5.1.2.2 e), 5.1.2.2 h)	Covered with respect to protection against the spread of fire (5.1.2.2 e)) Covered with respect to protection against explosion (5.1.2.2 h)).
14.4	5.2.3.4, 5.2.3.8, 5.2.3.10, 5.2.5, 5.3.1.3, 5.4.2, 5.4.6, 5.8.3, 5.8.4, 5.8.6, 6.2.19	Covered with respect to test connections (5.2.5, 5.3.1.3). Covered with respect to restricted access to sterilizer internals (5.2.3.4, 5.2.3.10, 5.4.2, 5.4.6). Covered with respect to controlled access and restricted manual process control in adjustment and maintenance (5.2.3.4, 5.2.3.8, 5.8.3, 5.8.4, 5.8.6, 6.2.19).
14.6	5.8.5, 6.4.2.5, 6.6.4.5, 7.7, 11.3 d)	Covered with respect to ambient lighting and minimal illumination, visual comfort and ergonomics (5.8.5, 6.4.2.5, 6.6.4.5, 7.7 and 11.3 d)).
14.7	11.5.1 g),11.5.2.h), Annex H a)	Covered with respect to instructions for sterilizer disposal 11.5.1 g), 11.5 2h) and Annex H a).
17.1	5.1.2.2 j), 5.1.2.4, 6.2, 6.3.2, 6.3.3, 6.3.4, 6.3.5, 6.3.6, 6.3.7, 6.4.1, 6.4.2, 6.4.4, 6.2.16, 6.5.2.3.1, 6.5.3.2.2, 8.1, 10.1.8	• Covered with respect to repeatability and performance of cycle parameters reproducible within tolerances (5.1.2.2 j), 6.2, 10.1.8). • Covered with respect to failures detected by the monitoring system (6.4.1, 6.4.2 and 6.4.4). • Covered with respect to a failure cause by a broken sensor detection (6.2.16) • Covered with respect to reliability by separation of control and monitoring system (6.3.2, 6.3.3, 6.3.4, 6.3.5, 6.3.6, 6.3.7, 6.5.2.3.1, 6.5.3.2.2). Covered with respect to EMC requirements (5.1.2.4, 8.1).
17.2	5.1.3.1, 6.2.1, 6.3.2, 6.3.3, 6.3.4, 6.3.5, 6.3.6, 6.3.7	Covered with respect to software safety classification during risk assessment (5.1.3.1, 6.3.2, 6.3.3, 6.3.4, 6.3.5, 6.3.6, 6.3.7). Covered with respect to verification and validation of software that impact safety for patients and other persons (6.2.1).
17.4	5.1.1.3	Covered with respect to authorized access to IT networks (5.1.1.3).
18.5	8.1	Covered with respect to electromagnetic emissions (8.1).
18.6	5.1.2.4	Covered with respect to EMC requirements (5.1.2.4).
18.7	5.1.2.2 b), 5.8.6, Annex G b)	Covered with respect to protection against electric shock (5.1.2.2 b), Annex G b)). Covered with respect to maintenance safety (5.8.6).
18.8	5.2.3.5, 5.2.3.9, 5.2.3.10, 5.4.2, 5.4.6, 5.8.3, 5.8.4	Covered with respect to restricted access to sterilizer internal equipment (5.2.3.5, 5.2.3.10, 5.4.2, 5.4.6). Covered with respect to controlled access and restricted manual process control in adjustment and maintenance (5.2.3.9, 5.8.3, 5.8.4).
20.1	5.1.2.2 c), d), k), 5.1.2.3, 5.4.2, 5.7.2, Annex G c)	Covered with respect to removal of persons/objects from moving door (5.1.2.3). Covered with respect to restricted access to sterilizer internals (5.4.2) e.g. moving parts and instruction for use (IFU) considering user knowledge and education. Covered with respect to mechanical risk (5.1.2.2 c), d), k), Annex G c)). Stability is covered during transport through design and instructions (5.7.2).
20.3	8.2	Covered in respect to noise emission (8.2).
20.6	5.1.2.2 f), 5.2.4.3, 8.4	Covered in respect to heat emission (5.1.2.2 f), 5.2.4.3, 8.4).
21.2	5.1.2.2 k), 5.2.3, 5.3.2.1, 5.3.3, 6.2.9, 6.2.4, 10.2.4.4	Covered with respect to doors safety and interlock to prevent unintentional release of H₂O₂ (5.1.2.2 k), 5.2.3, 5.3.2.1). Covered with respect to safe evacuation of Air, humidity and H2O2 (5.3.3). Covered with respect to safe pressure vessels enclosing stored energy (6.2.9, 6.2.4). Covered with respect to pressure change (10.2.4.4).
21.3	5.1.3.2, 5.8.7, 6.2.3, 6.6.2, 6.6.3, 6.6.4, 6.7.8, 7.7, 11.3 d)	Covered with respect to Status indicators readable, with identified function in appropriate positions (6.6.2, 6.6.3, 6.6.4). Covered with respect to understandable intended use of cycles (6.2.3). Covered with respect to ambient lighting and minimal illumination, visual comfort and ergonomics (5.1.3.2, 5.8.7, 6.7.8, 7.7, and 11.3 d)).
23.1	11.4, 11.5, 12	Covered with respect to identification of device and manufacturer on label (11.4, 12). Covered with respect to documents to be supplied with the sterilizer (11.5).
23.1 (a)	11.5, 12	Covered with respect to packaging and marking (12). Covered with respect to adapted and complete instructions for use (11.5).
23.1 (b)	11.4	Covered with respect to a section about marking and labelling (11.4).
23.1 (c)	11.4	Covered with respect to Marking (11.4).
23.1 (d)	11.5	Covered with respect to documentation to be supplied with the sterilizer (11.5)
23.1 (g)	11.5.1 r)	Covered with respect to user information about residual risks (11.5.1.r)).
23.2 (a)	11.4.3 e)	Covered with respect to device model (11.4.3 e)).
23.2 (c)	11.4.3 a)	Covered with respect to manufacturer (11.4.3 a)).
23.2 d)	11.4.3 b)	Covered with respect to manufacturer’s authorized representative (11.4.3 b)).
23.2 g)	11.4.3 f)	Covered with respect to unique identification number of sterilizer model and production year (11.4.3 f)).
23.2 h)	11.4.3 d),e),f) and g)	Covered with respect to unique identification number of sterilizer model and production year (11.4.3 d), e), f) and g)).
23.2 (j)	11.4.3 g)	Covered with respect to year of manufacture (11.4.3 g).
23.2 (k)	12	Covered with respect to instructions for handling, unpacking, transport and storage of the sterilizer (12).
23.2 (m)	11.5.1 q) and r)	Covered with respect to instructions on protective measures, warnings and precautions before use (11.5.1 q) and r).
23.4 (a)	11.4.3 a), 11.5.1 a)	Covered with respect to marking and labelling (11.4.3 a)) and instruction for use 11.5.1 a).
23.4 b)	11.5.1 c), d), e), f), g), h,) i), j), k), l), m), n), o), p), q), r)	Covered with respect to intended use (11.5.1 c), d), e), f), g), h), i), j), k), l), m), n), o), p), q), r)).
23.4 f)	11.5.1 c), d), e), f), g), h), i), j), k), l), m), n), o), p), q), r)	Covered with respect to intended use for Healthcare professionals (11.5.1 c), d), e,) f), g), h), i), j), k), l), m), n), o), p), q), r))
23.4 (g)	11.5.1 r)	Covered with respect to information on residual risk (11.5.1.r)).
23.4 (k)	11.3, A.3, A.4	Covered with respect to installation instructions (11.3). Covered with respect to instructions for Work tests and IQ (A.3 and A.4).
23.4 (k), 1st paragraph	11.5.1 j)	Covered with respect to regular and periodic maintenance with maintenance manual (11.5.1 j)).
23.4 (k), 2nd paragraph	11.5.1 f)	Covered with respect to consumables and accessories (11.5.1 f)).
23.4 (k), 4th paragraph	11.3	Covered with respect to installation instructions and tests to be conducted during normal operation (11.3).
23.4 (q)	11.5.1 f)	Covered with respect to characteristics of consumables, sterilizer load material and accessories (11.5.1 f)).
23.4 (v)	7.2.3, 11.5.1 g), Annex H a), Annex H d)	Covered with respect to disposal of the sterilizer (11.5.1 g), Annex H a)) and its consumable (7.2.3, Annex H d)).
23.4 (y)	11.5.1 s)	Covered with respect to date of issue or date of latest revision of the instructions for use (11.5.1 s)).

For devices which are also machinery within the meaning of Article 2(a) of Directive 2006/42/EC on Machinery, in accordance with Article 1, section 12 of Regulation 2017/745 the following Table ZA.2 details the relevant essential requirements of Directive 2006/42/EC on Machinery to the extent to which they are more specific than those in Chapter II of Annex I to this Regulation 2017/745, along with the corresponding clauses of this European Standard. Table ZA.2, however, does not imply any citation in the OJEU under the machinery directive and thus does not provide presumption of conformity for the machinery directive.

Table ZA.2 — Relevant Essential Health and Safety Requirements from Directive 2006/42/EC on machinery that are addressed by this European Standard (according to Article 1, section 12 of Regulation 2017/745)

Essential Health and Safety Requirements (EHSR) from Directive 2006/42/EC	Clause(s)/sub‐clause(s) of this EN	Remarks/Notes
1.1.2 a), 2nd paragraph	4.2.1, 5.1.1.1, 5.1.1.2, 5.7.1, 5.7.2, 11.3 a), 12	Covered with respect to risk reduction through labelling and instructions for transport and storage (5.7.1, 5.7.2, 12) Covered with respect to risk reduction through instructions, safety and warning advice for operation (11.3a)). Covered with respect to risk reduction through maintenance and disposal instructions (5.1.1.2 Covered with respect to Design and construction (4.2.1, 5.1.1.1).
1.1.2 c)	5.1.2, 5.1.3, 6.4.4, 7.2.2, Annex G h)	Covered with respect to protective measures for relevant hazards (5.1.2) and resistance to unintentional mechanical stress of containers, (7.2.2). Covered with respect to usability (5.1.3 and Annex G h)). Covered with respect to warnings and alarms in case of failure (6.4.4).
1.1.3	5.1.2.2 h), 5.3.2.1, 5.3.3.3, 8.3	Covered with respect to protective measures against liberated gases (5.1.2.2 h)) Covered with respect to hazards related to leakage hazards (5.3.3.3). Covered with respect to hazards related to fluids and exhaust emissions (5.3.2.1, 8.3).
1.1.4, 1st paragraph	7.7	Covered with respect to operation at relatively low lighting (7.7).
1.1.5	5.7.1, 5.7.2, 11.3 a), 12	Covered with respect to handling, lifting, packaging and stability during transport and storage (5.7.1, 5.7.2, and 12). Covered with respect to Instructions for handling during transport (11.3 a)).
1.1.6, 1st paragraph	5.1.3.2, 5.1.3.3, 5.6.1, 5.8.7, 8.4.2	Covered with respect to user knowledge, experience, training, ergonomics and usability (5.1.3.2, 5.1.3.3). Covered with respect to usability of loading equipment (5.6.1). Covered with respect to heat dissipation for ergonomic reasons (8.4.2). Covered with respect to instrumentation and indicating devices that can be readily viewed by the sterilizer operator (5.8.7).
1.1.7	8.3.1, 8.3.2, 5.2.4.3, 8.4.2	Covered with respect to protective measures against liberated H₂O₂ (8.3.1 and 8.3.2). Covered in respect to heat emission (5.2.4.3, 8.4.2).
1.2.1	5.1.2.4, 5.8.8, 5.8.5, 6.2.7, 6.2.10, 6.2.12, 6.2.13, 6.2.9, 6.2.16	Covered with respect to immunity to electromagnetic interferences (5.1.2.4). Covered with respect to protection of Controller from short circuits (6.2.7). Covered with respect to immunity of Controller (6.2.10). Covered with respect to safety of controller through risk management (6.2.12). Covered with respect to adequacy of controller to intended use (6.2.13). Covered with respect to failure of controller to (6.2.9). Covered with respect to monitoring of broken sensor (6.2.16). Covered with respect to adjustment of control settings only possible by the use of an access device. (5.8.8). Covered with respect to termination of sterilization cycles without causing hazardous situation (5.8.5)
1.2.2	5.8.1, 5.8.3, 5.8.7, 6.2.19, 6.6.2.3, 7.7	Covered with respect to user interfaces being located adequately (loading side or both ends) (5.8.1, 5.8.3). Covered with respect to user interfaces such as indicating, measuring and recording instruments) that can be readily viewed by the sterilizer operator (5.8.7, 7.7). Covered with respect indications complemented with Pictogram (6.6.2.3) Covered with respect to positioning, accessibility and protection of controller functions not causing additional risk (6.2. 19).
1.2.3	5.8.6, 5.8.1, 5.8.3, 6.4.2.6	Covered with respect to avoid starting normal operation during service mode (5.8.6). Control only to start operating cycles from sterilizer loading sides (5.8.1) with indicator on other side (5.8.3). Covered with respect to means for manual progression of cycle in maintenance, test and emergency by means of access device different from auto mode (6.4.2.6).
1.2.5	6.2.1, 6.2.20	Covered with respect to automatic modes with one or more pre-set operating cycles (6.2.1), and modes to allow manual access to controller with access device (6.2.20).
1.3.1	5.7.1, 5.7.2, 11.3 a), 12	Covered with respect to handling, lifting, packaging and stability during transport and storage (5.7.1, 5.7.2, and 12). Covered with respect to Instructions for handling during transport (11.3 a)).
1.3.2	5.1.2.2 d), 5.2.1.1, 5.1.2.2 g), 5.1.2.2.h), 5.3.1, 11.5.1 j) and 11.5.1 k), 11.5.2 a)	Covered with respect to materials used in chamber, paneling, welds and piping (5.2.1.1, 5.3.1). Covered with respect to Instructions for maintenance (11.5.1 j and k), 11.5.2 a)). Covered with respect to protection against hazards in relation to fluids, liberated gases, substances and explosion (5.1.2.2 g) and h)). Covered with respect to protection against hazards related to shock, impact and mechanical stress (5.1.2.2 d)).
1.3.3	5.1.2.2 c), 5.1.2.2 d), 5.4.5	Covered with respect to paneling (5.4.5). Covered with respect to protection against mechanical hazards and hazards related to mechanical functions (5.1.2.2 c), 5.1.2.2 d)).
1.3.6	5.1.3.2, 6.1.1	Covered with respect to pre-set operating cycles to adapt to different conditions and intended use (6.1.1). Covered with respect to the measures taken to address knowledge, experience, ergonomics and usability in case of variations in operating conditions (5.1.3.2).
1.3.7	5.1.2.2 d), 5.4	Covered with respect to sterilizer enclosed by panelling (5.4). Covered with respect to protection against mechanical hazards (5.1.2.2 d)).
1.3.8.2	5.1.2.2 c) and d), 5.2.3.10	Covered with respect to protective measures against mechanical hazard (5.1.2.2 c) and d)). Covered with respect to hazardous opening of a powered door (moving part) in case of double ended sterilizers (5.2.3.10).
1.3.9	5.5	Covered with respect to vibrations that can cause a loss of stability of the sterilizer (5.5)
1.4.1	5.1.1.2, 5.4.1, 5.4.2, 5.4.4, 5.4.6	Covered with respect to panels that remained attached (5.4.1). Covered with respect to prevention of unauthorized access through panels that do not bring additional hazard (5.1.1.2, 5.4.6). Covered with respect to panels that allow access (5.4.2, 5.4.4).
1.5.2	8.1.1	Covered with respect to Electrostatic Discharge (ESD) through Electromagnetic Compatibility (EMC) requirements (8.1.1).
1.5.5	8.4, 5.1.2.2 f)	Covered with respect to heat reduction (8.4) and covered with respect to protection against heat (5.1.2.2 f)
1.5.8	8.2	Covered in respect to noise emission (8.2).
1.5.9	5.5	Covered with respect to Reduction of vibrations (5.5).
1.5.13	5.2.1, 8.3.1	Covered with respect to non- toxic materials in direct or indirect product contact (5.2.1). Covered with respect to protective measures against liberated H2O2 (8.3.1)
1.5.14	5.1.2.3	Covered with respect to trapping of person inside the chamber (5.1.2.3).
1.6.1	5.4.1, 5.4.2, 5.4.4, 5.4.5, 5.4.6, 6.2.14, 6.2.19	Covered with respect to restricted access to sterilizer’s internals for maintenance or adjustments (5.4.1, 5.4.2, 5.4.4, 5.4.5, 5.4.6, 6.2.14, 6.2.19).
1.6.2	5.4.1, 5.4.2, 5.4.4, 5.4.5, 5.4.6, 6.2.14, 6.2.19	Covered with respect to restricted access to sterilizer’s internals for maintenance or adjustments (5.4.1, 5.4.2, 5.4.4, 5.4.5, 5.4.6, 6.2.14, 6.2.19).
1.6.3	7.1.3, 5.1.2.2 b)	Covered with respect to isolation (7.1.3). Covered with respect to protective measures against electric shocks (5.1.2.2 b)).
1.6.4	5.4.1, 5.4.2, 5.4.4, 5.4.5, 5.4.6, 6.2.14	Covered with respect to restricted access to sterilizer’s internals for maintenance or adjustments (5.4.1, 5.4.2, 5.4.4, 5.4.5, 5.4.6, 6.2.14)

Table ZA.3 — Prevailing terms of Regulation (EU) 2017/754 for the use of this European standard under that Regulation

Term used in this EN	Clause(s)/sub-clause(s) of this EN	Article in (EU) 2017/745 that defines or uses this term	Differences/Consequences
Medical device	3.36	Term defined in Art.2(1)	The core definition of Medical device has been employed from the MDR source. The difference is the addition of further examples that are relevant to sterilization standards that were too specialist for the generic document, but improve clarity/remove ambiguity as to whether certain accessories are in scope. This does not introduce any conflict with the MDR wording.

WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European Standard is maintained in the list published in the Official Journal of the European Union. Users of this standard should consult frequently the latest list published in the Official Journal of the European Union.

WARNING 2 — Other Union legislation may be applicable to the product(s) falling within the scope of this standard.

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This document is impacted by amendment EN IEC 61010‑1:2010/A1:2019. ↑
This document is impacted by amendment EN IEC 62366-1:2015/A1:2020 and by corrigendum EN IEC 62366-1:2015/AC:2015. ↑
This document is impacted by an European amendment EN ISO 14971:2019/A11:2021. ↑
Document impacted by EN ISO 11139:2018/A1:2024 ↑
Document impacted by EN ISO 11607‑1:2020/A1:2023 ↑
Document impacted by EN ISO 11607‑2:2020/A1:2023 ↑

Table of Contents

1.0 Scope

2.0 Normative references

3.0 Terms and definitions

4.0 General

4.1 Sterilizer type

4.1.1 Sterilizer development

4.1.2 Calibration

5.0 Sterilizer design and Construction

5.1 Safety and security

5.1.1 General

5.1.2 Protective measures

General

Specific requirements

5.1.3 Risk control and usability

5.2 Chamber

5.2.1 Materials

5.2.2 Chamber dimensions

Chamber

Usable Chamber space

5.2.3 Doors and interlocks of the chamber

5.2.4 Temperature control and insulation

5.2.5 Test connections

5.3 Further functional components

5.3.1 Pipework and fittings

5.3.2 H2O2 vaporizer

5.3.3 Evacuation system

5.4 Framework and panelling

5.4.1 Vibration

5.4.2 Ancillary equipment and components

5.4.3 Transport

5.4.4 User interfaces

6.0 Indicating, monitoring, controlling, and recording devices

6.1 General

6.1.1 Automatic control

6.1.2 Control and monitoring system

6.1.3 Failure

6.1.4 General

6.1.5 Fault

6.1.6 Power failure

6.1.7 Other failures

6.2 Instrumentation

6.2.1 General

6.2.2 Temperature measuring devices

Temperature parameters

Temperature sensor

Temperature measuring chains

6.2.3 Pressure measuring devices

Pressure parameters

Pressure measuring chains

6.2.4 Time measuring devices

6.2.5 Sterilizing agent control and measuring devices

6.3 Indicating devices

6.3.1 General requirements

6.3.2 Status indicators and indication

6.3.3 Operating cycle counter

6.3.4 Cycle parameters indicating device

Time indicating devices

Indicative devices for direct or indirect measure of VH2O2 concentration

Temperature indicating devices

Pressure indicating devices

Cycle parameter indications

6.4 Recorders

7.0 Services and local environment

7.1 General

7.1.1 Sterilant and sterilizing agent

7.1.2 Electrical supply

7.1.3 Water

7.1.4 Steam

7.1.5 Vacuum

7.1.6 Lighting

7.1.7 Drainage and discharges

7.1.8 Compressed air

7.1.9 Air and inert gases

7.1.10 Ventilation and environment

8.0 Emissions

8.1 Electromagnetic emissions

8.1.1 Noise

8.1.2 Exhaust emissions

8.1.3 Heat emission