ISO/PRF 11138-8

Sterilization of health care products -- Biological indicators

Stérilisation des produits de santé -- Indicateurs biologiques

General Information

• Status: Published
• ICS: 11.080.01 - Sterilization and disinfection in general
• Technical Committee: ISO/TC 198 - Sterilization of health care products
• Drafting Committee: ISO/TC 198/WG 4 - Biological indicators

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 11138-8
First edition
Sterilization of health care products —
Biological indicators —
Part 8:
Method for validation of a reduced
incubation time for a biological
indicator
Stérilisation des produits de santé — Indicateurs biologiques —
Partie 8: Méthode pour la validation d'un temps d'incubation réduit
pour un indicateur biologique
PROOF/ÉPREUVE
Reference number
ISO 11138-8:2021(E)
ISO 2021
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ISO 11138-8:2021(E)
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ISO 11138-8:2021(E)
Contents Page

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

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

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

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

3 Terms and definitions ..................................................................................................................................................................................... 1

4 General ............................................................................................................................................................................................................................ 2

5 Selection and preparation of samples ............................................................................................................................................ 3

6 Exposure and culturing ................................................................................................................................................................................. 3

7 Determination of reduced incubation time .............................................................................................................................. 4

Bibliography ................................................................................................................................................................................................................................ 7

© ISO 2021 – All rights reserved PROOF/ÉPREUVE iii
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ISO 11138-8:2021(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.

A list of all parts in the ISO 11138 series can be found on the ISO website.

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.
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ISO 11138-8:2021(E)
Introduction

A biological indicator incubation time is the minimum period of cultivation required before making a

final determination that a biological indicator is negative (shows no growth). The reference incubation

time for biological indicators for established sterilization processes such as moist heat and ethylene

oxide is 7 d (see ISO 11138-1:2017). In some instances where biological indicator results are needed as

part of the product release process, a 7-day incubation time might not be practical. This is especially

the case where biological indicators are used to monitor sterilization processes in hospitals or other

health care facilities such as dental or general practitioner offices.

The purpose of a reduced incubation time procedure is to demonstrate recovery of the surviving test

organisms within the specified reduced incubation time period. The reduced incubation time is a

function of the test method and conditions used to establish the incubation time and is independent of

the process parameters for the sterilization method used to deliver the lethality.

Biological indicators with an incubation time of less than 7 d (a Reduced Incubation Time, or RIT)

have been in use since the 1970s. The methodology to determine the RIT was originally created by the

biological indicator manufacturers. Later, the United States Food and Drug Administration published

guidance for manufacturers seeking regulatory clearance to market biological indicators to health

care facilities in the United States (ref. Guidance for Industry and FDA Staff, Biological Indicator (BI)

Premarket Notification [510(k)] Submissions, issued October 4, 2007, Attachment II). This guidance

contained a protocol for validating an incubation time that was less than 7 days. This document was

specific to regulations for commercial practices in a single country and did not address requirements

for RIT methodology outside of that application. The purpose of this document is to describe an

internationally agreed approach to the validation of the reduced incubation time of a biological

indicator.
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INTERNATIONAL STANDARD ISO 11138-8:2021(E)
Sterilization of health care products — Biological
indicators —
Part 8:
Method for validation of a reduced incubation time for a
biological indicator
1 Scope

1.1 This document specifies the requirements for a test method to be utilized to establish or confirm

a reduced incubation time (RIT) that is shorter than the 7-day reference incubation time specified in

7.3.2 of ISO 11138-1:2017 for biological indicators used to monitor moist heat sterilization processes or

ethylene oxide (EO) sterilization processes.

NOTE For biological indicators used for EO sterilization, the stated RIT is applicable to 100 % EO processes

or processes that use EO blends, regardless of the product load.

1.2 This document is applicable to manufacturers of biological indicators (BIs) and to end users of BIs

who intend to, if required by their quality system, establish, validate or confirm an RIT.

1.3 This document does not apply to biological indicators used to monitor dry heat, low temperature

steam formaldehyde (LTSF) or vaporized hydrogen peroxide (VH2O2) sterilization processes.

NOTE The method described in this document to establish an RIT for biological indicators used to monitor

moist heat or EO sterilization processes has been used extensively for many years. However, there is limited

experience in use of this method to establish an RIT for biological indicators used to monitor dry heat, low

temperature steam formaldehyde or vaporized hydrogen peroxide sterilization processes. This document,

therefore, does not include these sterilization processes.
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 18472, Sterilization of health care products — Biological and chemical indicators — Test equipment

3 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:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
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ISO 11138-8:2021(E)
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
carrier
supporting material on or in which test microorganisms are deposited
[SOURCE: ISO 11139:2018, 3.33]
3.3
culture condition

combination of growth media and manner of incubation used to promote germination, growth and/or

multiplication of microorganisms

Note 1 to entry: The manner of incubation can include the temperature, time and any other conditions specified

for incubation.
[SOURCE: ISO 11139:2018, 3.70]
3.4
fractional cycle
...