Sterilization of health care products - Biological and chemical indicators - Test equipment (ISO 18472:2018)

This document specifies the requirements for test equipment to be used to:
— test biological indicators for steam, ethylene oxide gas and dry heat sterilization processes for
conformity to the requirements given in ISO 11138 series;
— test chemical indicators for steam, ethylene oxide gas, dry heat and vaporized hydrogen peroxide
sterilization processes for conformity to the requirements given in ISO 11140-1:2014.
This document also provides informative methods useful in characterizing the performance of
biological and chemical indicators for intended use and for routine quality control testing.
This document does not specify requirements for test equipment for processes specifically for testing
chemical and biological indicators intended to monitor isolator and room biodecontamination processes
at atmospheric pressure.
ISO 11138-2:2017, ISO 11138-3:2017, ISO 11138-4:2017 and ISO 11140-1:2014 require the use of
resistometers specified in this document, and these resistometers are used in conjunction with the test
methods specified in the appropriate parts of ISO 11138 series and ISO 11140 series.
Resistometers for low temperature steam and formaldehyde indicators are not included in this
document. Test methods using laboratory apparatus for low temperature steam and formaldehyde are
included in ISO 11138-5:2017.
Test equipment for testing Type 2 (e.g. Bowie Dick) chemical indicators are specified in ISO 11140-3:2007,
ISO 11140-4:2007, and ISO 11140-5:2007.

Sterilisation von Produkten für die Gesundheitsfürsorge - Biologische und chemische Indikatoren - Prüfausrüstung (ISO 18472:2018)

Stérilisation des produits de santé - Indicateurs biologiques et chimiques - Appareillage d'essai (ISO 18472:2018)

Le présent document spécifie les exigences relatives à l'équipement d'essai à utiliser pour:
— s'assurer de la conformité des indicateurs biologiques des procédés de stérilisation à la vapeur, à l'oxyde d'éthylène gazeux et à la chaleur sèche avec les exigences indiquées dans la série ISO 11138;
— s'assurer de la conformité des indicateurs chimiques des procédés de stérilisation à la vapeur, à l'oxyde d'éthylène gazeux, à la chaleur sèche et au peroxyde d'hydrogène vaporisé avec les exigences indiquées dans l'ISO 11140‑1:2014.
Le présent document fournit également des méthodes informatives permettant de caractériser les performances des indicateurs biologiques et chimiques pour l'usage prévu et pour les essais de contrôle qualité de routine.
Le présent document ne spécifie pas les exigences relatives à l'équipement d'essai pour les procédés spécifiques aux essais des indicateurs biologiques et chimiques destinés à surveiller les procédés d'isolateur et de biodécontamination des salles à la pression atmosphérique.
L'ISO 11138‑2:2017, l'ISO 11138‑3:2017, l'ISO 11138‑4:2017 et l'ISO 11140‑1:2014 requièrent l'utilisation des résistomètres spécifiés dans le présent document et ces résistomètres sont utilisés conjointement avec les méthodes d'essai spécifiées dans les parties applicables de la série ISO 11138 et de la série ISO 11140.
Les résistomètres utilisés pour traiter les indicateurs à la vapeur d'eau et au formaldéhyde à basse température ne sont pas abordés dans le présent document. Les méthodes d'essai utilisant un appareillage de laboratoire pour la vapeur d'eau et le formaldéhyde à basse température sont indiquées dans l'ISO 11138‑5:2017.
Les équipements d'essai des indicateurs chimiques de classe 2 (par exemple Bowie et Dick) sont spécifiés dans l'ISO 11140‑3:2007, l'ISO 11140‑4:2007 et l'ISO 11140‑5:2007.

Sterilizacija izdelkov za zdravstveno nego - Biološki in kemični indikatorji - Preskusna oprema (ISO 18472:2018)

Ta dokument določa zahteve za preskusno opremo za:
– preskušanje bioloških indikatorjev za sterilizacijo s paro, etilenoksidnim plinom in suho toploto za namene izpolnitve zahtev iz skupine standardov ISO 11138;
– preskušanje kemičnih indikatorjev za sterilizacijo s paro, etilenoksidnim plinom, suho toploto in uplinjenim vodikovim peroksidom za namene izpolnitve zahtev iz standarda ISO 11140-1:2014.
Ta dokument vsebuje tudi informativne metode, ki so uporabne za opis učinkovitosti bioloških in kemičnih indikatorjev za predvideno uporabo ter za redne preskuse kontrole kakovosti.
Ta dokument ne določa zahtev za preskusno opremo za postopke, specifične za preskušanje kemičnih in bioloških indikatorjev, ki so namenjeni spremljanju procesov biološke dekontaminacije izolatorja in prostorov
pri atmosferskem tlaku.
ISO 11138-2:2017, ISO 11138-3:2017, ISO 11138-4:2017 in ISO 11140-1:2014 zahtevajo uporabo merilnikov odpornosti, opredeljenih v tem dokumentu, pri čemer se ti merilniki uporabljajo skupaj s preskusnimi metodami, določenimi v ustreznih delih skupin standardov ISO 11138 in ISO 11140.
Ta dokument ne zajema merilnikov odpornosti za indikatorje pri postopkih s paro nizke temperature in formaldehidom. Preskusne metode z uporabo laboratorijskih naprav za paro nizke temperature in formaldehid so zajete v standardu ISO 11138-5:2017.
Oprema za preskušanje kemijskih indikatorjev tipa 2 (npr. Bowie Dick) je določena v standardih ISO 11140-3:2007, ISO 11140-4:2007 in ISO 11140-5:2007.

General Information

Status
Published
Public Enquiry End Date
19-Jan-2017
Publication Date
12-Nov-2018
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
19-Oct-2018
Due Date
24-Dec-2018
Completion Date
13-Nov-2018

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SLOVENSKI STANDARD
SIST EN ISO 18472:2018
01-december-2018
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Sterilization of health care products - Biological and chemical indicators - Test equipment

(ISO 18472:2018)

Sterilisation von Produkten für die Gesundheitsfürsorge - Biologische und chemische

Indikatoren - Prüfausrüstung (ISO 18472:2018)

Stérilisation des produits de santé - Indicateurs biologiques et chimiques - Appareillage

d'essai (ISO 18472:2018)
Ta slovenski standard je istoveten z: EN ISO 18472:2018
ICS:
11.080.01 Sterilizacija in dezinfekcija na Sterilization and disinfection
splošno in general
SIST EN ISO 18472:2018 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 18472:2018
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SIST EN ISO 18472:2018
EN ISO 18472
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2018
EUROPÄISCHE NORM
ICS 11.080.01 Supersedes EN ISO 18472:2006
English Version
Sterilization of health care products - Biological and
chemical indicators - Test equipment (ISO 18472:2018)

Stérilisation des produits de santé - Indicateurs Sterilisation von Produkten für die

biologiques et chimiques - Appareillage d'essai (ISO Gesundheitsfürsorge - Biologische und chemische

18472:2018) Indikatoren - Prüfausrüstung (ISO 18472:2018)
This European Standard was approved by CEN on 9 May 2018.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18472:2018 E

worldwide for CEN national Members.
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SIST EN ISO 18472:2018
EN ISO 18472:2018 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 18472:2018
EN ISO 18472:2018 (E)
European foreword

This document (EN ISO 18472:2018) has been prepared by Technical Committee ISO/TC 198

"Sterilization of health care products" in collaboration with Technical Committee CEN/TC 102

“Sterilizers and associated equipment for processing of medical devices” the secretariat of which is held

by DIN.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by March 2019, and conflicting national standards shall

be withdrawn at the latest by March 2019.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 18472:2006.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
Endorsement notice

The text of ISO 18472:2018 has been approved by CEN as EN ISO 18472:2018 without any modification.

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SIST EN ISO 18472:2018
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SIST EN ISO 18472:2018
INTERNATIONAL ISO
STANDARD 18472
Second edition
2018-08
Sterilization of health care products —
Biological and chemical indicators —
Test equipment
Stérilisation des produits de santé — Indicateurs biologiques et
chimiques — Appareillage d'essai
Reference number
ISO 18472:2018(E)
ISO 2018
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SIST EN ISO 18472:2018
ISO 18472:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
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SIST EN ISO 18472:2018
ISO 18472:2018(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Performance requirements for resistometers ...................................................................................................................... 4

4.1 Intended use .............................................................................................................................................................................................. 4

4.2 Test methods ............................................................................................................................................................................................. 4

4.3 Air leakage test........................................................................................................................................................................................ 4

4.4 Steam resistometer performance requirements ....................................................................................................... 5

4.4.1 Measurement accuracy .............................................................................................................................................. 5

4.4.2 Data ............................................................................................................................................................................................. 5

4.4.3 Process control .................................................................................................................................................................. 5

4.4.4 General steam resistometer requirements ............................................................................................... 6

4.4.5 Air leakage test .................................................................................................................................................................. 7

4.4.6 Operation of steam resistometer ....................................................................................................................... 7

4.5 Ethylene oxide gas resistometer performance requirements ........................................................................ 7

4.5.1 Measurement accuracy .............................................................................................................................................. 7

4.5.2 Data ............................................................................................................................................................................................. 8

4.5.3 Process control .................................................................................................................................................................. 8

4.5.4 General ethylene oxide gas resistometer requirements ................................................................ 9

4.5.5 Air leakage test ...............................................................................................................................................................10

4.5.6 Operation of ethylene oxide gas resistometer .....................................................................................10

4.6 Dry heat (heated air) resistometer performance requirements ...............................................................10

4.6.1 Measurement accuracy ...........................................................................................................................................10

4.6.2 Data ..........................................................................................................................................................................................11

4.6.3 Process control ...............................................................................................................................................................11

4.6.4 General dry heat (heated air) resistometer requirements .......................................................12

4.6.5 Operation of dry heat (heated air) resistometer ...............................................................................12

4.7 Vaporized hydrogen peroxide resistometer performance requirements .........................................13

4.7.1 Measurement accuracy ...........................................................................................................................................13

4.7.2 Recording interval .......................................................................................................................................................13

4.7.3 Process control ...............................................................................................................................................................13

4.7.4 General vaporized hydrogen peroxide resistometer requirements .................................14

4.7.5 Air leakage test ...............................................................................................................................................................15

4.7.6 Operation of vaporized hydrogen peroxide resistometer .........................................................15

5 Calibration ...............................................................................................................................................................................................................15

Annex A (informative) Additional performance characterization — Steam ............................................................16

Annex B (informative) Additional performance characterization — Ethylene oxide gas ..........................19

Annex C (informative) Additional performance characterization — Dry heat......................................................22

Annex D (informative) Resistometer documentation and derivations .........................................................................24

Bibliography .............................................................................................................................................................................................................................30

© ISO 2018 – All rights reserved iii
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SIST EN ISO 18472:2018
ISO 18472:2018(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso

.org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 198, Sterilization of health care products.

This second edition cancels and replaces the first edition (ISO 18472:2006), which has been technically

revised.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2018 – All rights reserved
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SIST EN ISO 18472:2018
ISO 18472:2018(E)
Introduction

To test the performance of biological and chemical indicators, specific test equipment is required.

This document specifies the performance requirements for the test equipment to be used to establish

the response of biological and chemical indicators to critical process variables. This document does

not apply to test equipment for indicators used in irradiation, isolator/room biodecontamination (at

atmospheric pressure), or low temperature steam and formaldehyde processes.

Resistometers constitute test equipment designed to create precise and repeatable sterilizing

environments, allowing the evaluation of their effect on biological inactivation kinetics, chemical

reactions, material degradation and product bioburden. Resistometers allow precise variation of the

environmental conditions and cycle sequences in order to produce controlled physical studies. When

used with the defined test methods given in the appropriate parts of ISO 11138 for biological indicators

and ISO 11140 for chemical indicators, the results of these studies can be used to demonstrate

conformance of biological indicators and chemical indicators to these standards.

Resistometers differ from conventional sterilizers. Instrumentation selection and control requirements

for resistometers are based upon mathematical models in which rates of reaction, measurement

accuracy and process control requirements are evaluated to quantify the effects induced by test

equipment-controlled variables. The requirements for accurate measurement, precise control,

and rapid rates of change approach limits of commercially available process control and calibration

instrumentation measurement accuracy. The measurement and control requirements often prohibit

practical validation of a resistometer using procedures that might be employed in a conventional heat

or chemical sterilization system. Resistometers are considered test equipment rather than sterilizers;

therefore, an understanding of instrumentation and process design is critical in clarifying requirements

on precision and measurement accuracy. Practical design takes the following into consideration:

— achievable measurement and control;
— acceptable equipment induced variation in test results;
— economic design (utilizing tight process controls only where required);
— test method correlation with intended use;

— historical knowledge applied to test procedures and an understanding of micro-environmental

physical phenomena;

— testing and analysis alternatives, when accurate quantitative determinations exceed physical

measurement/control limits.
© ISO 2018 – All rights reserved v
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SIST EN ISO 18472:2018
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SIST EN ISO 18472:2018
INTERNATIONAL STANDARD ISO 18472:2018(E)
Sterilization of health care products — Biological and
chemical indicators — Test equipment
1 Scope
This document specifies the requirements for test equipment to be used to:

— test biological indicators for steam, ethylene oxide gas and dry heat sterilization processes for

conformity to the requirements given in ISO 11138 series;

— test chemical indicators for steam, ethylene oxide gas, dry heat and vaporized hydrogen peroxide

sterilization processes for conformity to the requirements given in ISO 11140-1:2014.

This document also provides informative methods useful in characterizing the performance of

biological and chemical indicators for intended use and for routine quality control testing.

This document does not specify requirements for test equipment for processes specifically for testing

chemical and biological indicators intended to monitor isolator and room biodecontamination processes

at atmospheric pressure.

ISO 11138-2:2017, ISO 11138-3:2017, ISO 11138-4:2017 and ISO 11140-1:2014 require the use of

resistometers specified in this document, and these resistometers are used in conjunction with the test

methods specified in the appropriate parts of ISO 11138 series and ISO 11140 series.

Resistometers for low temperature steam and formaldehyde indicators are not included in this

document. Test methods using laboratory apparatus for low temperature steam and formaldehyde are

included in ISO 11138-5:2017.

Test equipment for testing Type 2 (e.g. Bowie Dick) chemical indicators are specified in ISO 11140-3:2007,

ISO 11140-4:2007, and ISO 11140-5:2007.
2 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.

ISO 11138-1:2017, Sterilization of health care products — Biological indicators — Part 1: General

requirements

ISO 11138-2:2017, Sterilization of health care products — Biological indicators — Part 2: Biological

indicators for ethylene oxide sterilization processes

ISO 11138-3:2017, Sterilization of health care products — Biological indicators — Part 3: Biological

indicators for moist heat sterilization processes

ISO 11138-4:2017, Sterilization of health care products — Biological indicators — Part 4: Biological

indicators for dry heat sterilization processes

ISO 11138-5:2017, Sterilization of health care products — Biological indicators — Part 5: Biological

indicators for low-temperature steam and formaldehyde sterilization processes

ISO 11140-1:2014, Sterilization of health care products — Chemical indicators — Part 1: General

requirements
© ISO 2018 – All rights reserved 1
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SIST EN ISO 18472:2018
ISO 18472:2018(E)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 11138-1:2017, ISO 11138-2:2017,

ISO 11138-3:2017, ISO 11138-4:2017, ISO 11138-5:2017, and ISO 11140-1:2014 and the following 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 https: //www .iso .org/obp
3.1
biological indicator

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

sterilization process
[SOURCE: ISO 11139:2018, 3.29]
3.2
calibration

operation that, under specified conditions, in a first step, establishes a relation between the quantity

values with measurement uncertainties provided by the measurement standards and corresponding

indications with associated measurement uncertainties and, in a second step, uses this information to

establish a relation for obtaining a measurement result from an indication

[SOURCE: ISO/IEC Guide 99:2007, 2.39, modified — NOTE 1, 2, and 3 have been deleted.]

3.3
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: ISO 11139:2018, 3.43]
3.4
come-down period

time elapsed from the termination of the exposure period to an established null

reaction point
[SOURCE: ISO 11139:2018, 3.56]
3.5
come-up period

time elapsed from the introduction of the sterilizing agent to the attainment of the

specified conditions
[SOURCE: ISO 11139:2018, 3.57]
3.6
indicator exposure period

duration between the initial attainment to the termination of the specified exposure conditions

[SOURCE: ISO 11139:2018, 3.140]
3.7
measurement accuracy

closeness of the agreement between a measured quantity value and a true quantity value of a measurand

Note 1 to entry: “Accuracy” is a qualitative concept.
Note 2 to entry: The term “precision” should not be used for “accuracy”.
2 © ISO 2018 – All rights reserved
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SIST EN ISO 18472:2018
ISO 18472:2018(E)

[SOURCE: ISO/IEC Guide 99:2007, 2.13, modified — The terms “accuracy of measurement” and

“accuracy” have been deleted. NOTE 1 and 2 have been modified. NOTE 3 has been deleted.]

3.8
measurement precision

closeness of agreement between indications or measured quantity values obtained by replicate

measurements on the same or similar objects under specified conditions

Note 1 to entry: Measurement precision is usually expressed numerically by measures of imprecision, such as

standard deviation, variance, or coefficient of variation under the specified conditions of measurement.

Note 2 to entry: The ‘specified conditions’ can be, for example, repeatability conditions of measurement,

intermediate precision conditions of measurement, or reproducibility conditions of measurement.

Note 3 to entry: Measurement precision is used to define “measurement repeatability”, “intermediate

measurement precision”, and “measurement reproducibility”.

Note 4 to entry: Sometimes “measurement precision” is erroneously used to mean measurement accuracy.

[SOURCE: ISO/IEC Guide 99:2007, 2.15, modified — The term “precision” has been deleted. The NOTEs

have been modified.]
3.9
null reaction point
terminating set of conditions that have no significant effect on the indicator
3.10
record, verb
collect, store and make accessible
[SOURCE: ISO 11139:2018, 3.223]
3.11
reference standard

measurement standard designated for the calibration of other measurement standards for quantities of

a given kind in a given organization or at a given location

[SOURCE: ISO/IEC Guide 99:2007, 5.6, modified — The term name has been simplified.]

3.12
resistometer

test equipment designed to create specified combinations of the physical and/or chemical parameters

of a sterilization process
[SOURCE: ISO 11139:2018, 3.233]
3.13
response time

period required for a 90 % change in sensor output when exposed to a step change in the

variable being measured

Note 1 to entry: It may be necessary to determine the sensor response time using a faster data sampling rate

than the minimum for the equipment specified in this document. Documentary evidence from the sensor

manufacturer's stated response time is equally acceptable as proof of conformance.

[SOURCE: ISO 11139:2018, 3.234, modified — Note 1 to entry has been added.]
3.14
saturated steam
water vapour in a state of equilibrium between its liquid and gas phases
[SOURCE: ISO 11139:2018, 3.241]
© ISO 2018 – All rights reserved 3
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SIST EN ISO 18472:2018
ISO 18472:2018(E)
3.15
stabilization period

elapsed time from the attainment of the minimum specified exposure conditions until the end of the

specified time to achieve steady state conditions
[SOURCE: ISO 11139:2018, 3.261]
3.16
steady state period

portion of the exposure period which begins after the stabilization period and terminates

at the end of the exposure period
[SOURCE: ISO 11139:2018, 3.266]
3.17
sterilant
chemical or combination of chemicals used to generate a sterilizing agent
[SOURCE: ISO 11139:2018, 3.268]
4 Performance requirements for resistometers
4.1 Intended use

The resistometer is intended to be used to expose test samples under stated test conditions, and

therefore shall be capable of producing cycle sequences as required for specific test methods.

Depending upon the test methods defined in ISO 11138-2:2017, ISO 11138-3:2017, ISO 11138-4:2017

and ISO 11140-1:2014, the resistometer utilized need only verify those limits necessary to characterize

the chemical or biological indicators being tested.

NOTE 1 The following requirements define the conditions to be achieved in the vessel in which the sample is

to be placed, but the means by which these conditions are to be controlled are not addressed.

NOTE 2 Piping connected to the chamber can modify the total volume of the chamber.

4.2 Test methods

The equipment specified in this document shall be used with the detailed test methods given in

ISO 11138-1:2017, ISO 11138-2:2017, ISO 11138-3:2017, ISO 11138-4:2017, and ISO 11140-1:2014.

The performance of resistometers can be influenced by the nature of the load being used. The

performance requirements listed in Tables 2, 4, 6, and 8 shall be met during testing of indicators as well

as during empty chamber conditions.

NOTE Tolerances might be compounded when taking into consideration the tolerances designated for the

performance of the resistometer and the tolerances for performance testing of biological (ISO 11138-1:2017,

ISO 11138-2:2017, ISO 11138-3:2017, ISO 11138-4:2017) and chemical (ISO 11140-1:2014) indicators.

4.3 Air leakage test

4.3.1 With the temperature stabilized and the chamber empty (except for fixed furniture and necessary

monitoring sensors) start the test cycle. When the pressure in the chamber has reached or is below the

value corresponding to the lowest operating vacuum of the test cycle air removal stages, close all the

valves connected to the chamber and stop the vacuum pump. Observe and record the time, t , and the

absolute pressure, p . Allow evaporation of condensate in the chamber for 300 s ± 10 s and then observe

4 © ISO 2018 – All rights reserved
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SIST EN ISO 18472:2018
ISO 18472:2018(E)

and record the absolute pressure, p , in the chamber and the time, t . After a further 600 s ± 10 s, again

2 2
observe and record the absolute pressure, p , and the time, t .
3 3

The resistometer may be equipped with a test cycle for air leakage that will carry out this procedure

automatically and display the air leakage in kPa/min (mbar/min).

4.3.2 At the end of the test calculate the rate of pressure rise for the 600 s period.

NOTE 1 If the value of (p − p ) is greater than 2 kPa (20 mbar), this could be due to the initial presence of

2 1
exce
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Questions, Comments and Discussion

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