prEN ISO 11140-4

SLOVENSKI STANDARD
01-september-2025
Sterilizacija izdelkov za zdravstveno nego - Kemijski indikatorji - 4. del: Sistemi
indikatorjev tipa 2, ki se uporabljajo namesto Bowie-Dickovega preskusa za
ugotavljanje prodiranja pare (ISO/DIS 11140-4:2025)
Sterilization of health care products - Chemical indicators - Part 4: Type 2 indicator
systems as an alternative to the Bowie and Dick-type test for the detection of steam
penetration (ISO/DIS 11140-4:2025)
Sterilisation von Produkten für die Gesundheitsfürsorge - Chemische Indikatoren - Teil 4:
Indikatoren der Klasse 2, die alternativ zum Bowie-Dick-Test für den Nachweis der
Dampfdurchdringung verwendet werden (ISO/DIS 11140-4:2025)
Stérilisation des produits de santé - Indicateurs chimiques - Partie 4: Systèmes
d'indicateurs de Type 2 comme alternative à l'essai de Bowie et Dick pour la détection
de la pénétration de la vapeur (ISO/DIS 11140-4:2025)
Ta slovenski standard je istoveten z: prEN ISO 11140-4
ICS:
11.080.01 Sterilizacija in dezinfekcija na Sterilization and disinfection
splošno in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 11140-4
ISO/TC 198
Sterilization of health care
Secretariat: ANSI
products — Chemical indicators —
Voting begins on:
Part 4: 2025-07-30
Type 2 indicator systems as an
Voting terminates on:
2025-10-22
alternative to the Bowie and Dick-
type test for the detection of steam
penetration
Stérilisation des produits de santé — Indicateurs chimiques —
Partie 4: Systèmes d'indicateurs de Type 2 comme alternative à
l'essai de Bowie et Dick pour la détection de la pénétration de la
vapeur
ICS: 11.080.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 11140-4:2025(en)
DRAFT
ISO/DIS 11140-4:2025(en)
International
Standard
ISO/DIS 11140-4
ISO/TC 198
Sterilization of health care
Secretariat: ANSI
products — Chemical indicators —
Voting begins on:
Part 4:
Type 2 indicator systems as an
Voting terminates on:
alternative to the Bowie and Dick-
type test for the detection of steam
penetration
Stérilisation des produits de santé — Indicateurs chimiques —
Partie 4: Systèmes d'indicateurs de Type 2 comme alternative à
l'essai de Bowie et Dick pour la détection de la pénétration de la
vapeur
ICS: 11.080.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 11140-4:2025(en)
ii
ISO/DIS 11140-4:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General . 3
5 Requirements . 3
6 Indicator format . 4
7 Performance requirements . . 5
8 Packaging and labelling . 6
Annex A (normative) Standard test cycles . 9
Annex B (normative) Estimation of visual difference between colour of the substrate and of the
changed or unchanged indicator system by determination of relative reflectance density . 14
Annex C (normative) Determination of uniform colour change on exposure to saturated steam .18
Annex D (normative) Determination of equivalence of the alternative indicator to the Bowie
and Dick test . 19
Annex E (normative) Determination of reproducibility of fail conditions created in a standard
test pack by air injection, air leak and retained air systems .21
Annex F (normative) Determination of indicator colour change on exposure to dry heat .25
Annex G (normative) Determination of shelf life of indicators .26
Annex H (normative) Steam exposure apparatus and steam for test purposes .27
Annex I (normative) Standard test pack .30
Annex J (normative) Air injection system . .31
Annex K (informative) Relationship between chemical indicator components .33
Annex ZA (informative) Relationship between this European Standard and the General Safety
and Performance Requirements of Regulation (EU) 2017/745 aimed to be covered .34
Bibliography .37

iii
ISO/DIS 11140-4:2025(en)
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 third edition cancels and replaces the second edition (ISO 11140-4:2007), which has been technically
revised.
The main changes are as follows:
— change of title from class 2 indicator to type 2 indicator to align with ISO 11140-1;
— correct use of the defined terms indicator and indicator system to align with ISO 11140-1;
— updated normative references;
— inserted common Clause 4 for ISO/TC 198 documents, replacing Clause 8;
— added Annex M, modified from ISO 11140-1.
A list of all parts in the ISO 11140 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.

iv
ISO/DIS 11140-4:2025(en)
Introduction
[1]
The Bowie and Dick test is a test for steam sterilizers for products to be sterilized that are within sterile
barrier systems or other porous loads. As such it is performed during the demonstration of conformance of
steam sterilizers to EN 285 and as a routine test of performance in ISO 17665. The test method is described
in EN 285.
A failure of the Bowie and Dick test is symptomatic of a number of potential problems with the sterilizer that
could compromise the uniform sterilization of a load to be processed. This failure is not conclusive proof
that the fault in the sterilizer is due to air retention, air leakage or non-condensable gases, and it can be
necessary to investigate other causes of failure.
The Bowie and Dick test was conceived as a test for successful air removal from high-vacuum porous-load
[1]
sterilizers used in the sterilization of health care products . A successful Bowie and Dick test indicates
sufficient air removal to facilitate rapid and even penetration of steam into the test load. The presence of air
within the pack, due to an inefficient air removal stage, an air leak during this stage or non-condensable gases
in the steam supply, are circumstances which can lead to failure of the test. The result of the test can also
be affected by other factors which inhibit steam penetration into the test load. The test does not necessarily
demonstrate either achievement of the required temperature or maintenance of that temperature for the
required time to achieve sterilization.
The Bowie and Dick test consists of two components:
a) a small standardized test load;
b) a chemical indicator to detect the presence of steam.
[1]
The Bowie and Dick test as originally described utilized huckaback towels as the material for the test
load. The test as described in EN 285 uses cotton sheets for this purpose.
Indicators intended as an alternative to the Bowie and Dick test use different materials for the test load and
employ indicators specifically formulated for use with the defined test load. Because a range of different
tests in different countries have historically been termed the Bowie and Dick test, the term Bowie and Dick-
type test is used in this document.
This document specifies the performance of the indicator in combination with the test load with which it is
intended to be used. The test load may be presented with the indicator already incorporated and intended
for single use, or it may be intended for multiple use with a new indicator to be inserted prior to each use.
The indicator system for which the performance is specified in this document is intended to indicate when
steam penetration has been inadequate. An indicator system meeting this specification is not intended to
identify which of the potential causes of poor steam penetration was responsible for the failure indicated by
the test.
v
DRAFT International Standard ISO/DIS 11140-4:2025(en)
Sterilization of health care products — Chemical indicators —
Part 4:
Type 2 indicator systems as an alternative to the Bowie and
Dick-type test for the detection of steam penetration
WARNING — The use of this document can involve hazardous materials, operations and equipment. It
is the responsibility of the user of this document to establish appropriate safety and health practices
and determine the applicability of any other restrictions prior to use.
1 Scope
This document specifies the performance for a Type 2 indicator system to be used as an alternative to the Bowie
and Dick-type test for steam sterilizers for wrapped health care goods (instruments, etc., and porous loads).
NOTE The Bowie and Dick-type test is used for routine testing of steam sterilizers and validation of steam
sterilization processes.
An indicator system conforming with this document incorporates an indicator together with a specified
material which is used as a test load. This test load may, or may not, be re-usable. This document does not
specify requirements for the test load, but specifies the performance of the indicator system (the indicator
in combination with the test load with which it is intended to be used). The indicator system specified in this
document is intended to identify poor steam penetration but does not necessarily indicate the cause of this
poor steam penetration.
This document does not include test methods to establish the suitability of these indicator systems for use in
sterilizers in which the air removal stage does not include evacuation below atmospheric pressure.
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.
EN 285:2015+A1:2021, Sterilization — Steam sterilizers — Large sterilizers
ISO/CIE 11664-2:2022, Colorimetry — Part 2: CIE standard illuminants
ISO 11140-1:2014, Sterilization of health care products — Chemical indicators — Part 1: General requirements
IEC 60584-1:2013, Thermocouples — Part 1: EMF specifications and tolerances
IEC 60751:2022, Industrial platinum resistance thermometers and platinum temperature sensors
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11140-1 and the following apply.
ISO and IEC maintain terminology 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/

ISO/DIS 11140-4:2025(en)
3.1
chamber reference temperature
temperature at a specified point within the chamber
Note 1 to entry: The specified point is usually located in the chamber drain or active chamber discharge of the steam
exposure apparatus.
[SOURCE: ISO 11139:2018/Amd 1:2024, 3.38, modified — Note 1 to entry has been added.]
3.2
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
Note 1 to entry: See Annex K.
[SOURCE: ISO 11139:2018/Amd 1:2024, 3.43, modified — Note 1 to entry has been added.]
3.3
chemical indicator system
combination of a chemical indicator (3.2) and a specific test load
Note 1 to entry: See Annex K.
[SOURCE: ISO 11139:2018/Amd 1:2024, 3.43.1, modified — Note 1 to entry has been added.
3.4
exposure time
period for which the chamber reference temperature lies within the sterilization temperature band
3.5
pre-assembled pack
indicator system in which the indicator is incorporated into the test load during the manufacturing process
and which is supplied ready for use
3.6
reference fault period
period of 30 s commencing when the chamber reference temperature attains the set operating temperature
3.7
sterilization temperature
minimum temperature on which the evaluation of sterilization efficacy is based
Note 1 to entry: This is the minimum temperature of the sterilization temperature band.
Note 2 to entry: The use of the word sterilization within this and other definitions is not intended to imply that
sterilizing conditions will take place under the test cycle conditions.
[SOURCE: ISO 11139:2018/Amd 1:2024, 3.286, modified — Note 1 to entry and Note 2 to entry have been added.]
3.8
temperature band
range of temperatures expressed as the minimum and maximum temperatures in the usable chamber space
during a holding time
Note 1 to entry: These temperatures are usually stated in whole units.
[SOURCE: ISO 11139:2018/Amd 1:2024, 3.293, modified — Note 1 to entry has been added.]

ISO/DIS 11140-4:2025(en)
3.9
temperature depression
thermodynamic temperature difference in kelvin (Celsius) given by (chamber reference temperature, in
Celsius) minus (temperature in the standard test pack, in Celsius)
EXAMPLE 2 K (2 °C).
3.10
test equilibration time
time elapsed after the chamber reference temperature attains the set operating temperature
until the temperature within the standard test pack is the same as the chamber reference temperature
[SOURCE: ISO 11139:2018/Amd 1:2024, 3.297]
3.11
user-assembled pack
combination of the indicator and the test load created at the point of use
[SOURCE: ISO 11139:2018/Amd 1:2024, 3.312]
4 General
4.1 The development, validation and routine control of a sterilization process is a critical element in
product realization of health care product. To ensure the consistent implementation of the requirements
specified in this document, the necessary processes need to be established, implemented and maintained.
Processes of particular importance in relation to the development, validation and routine control of a
sterilization process include but are not limited to:
— control of documentation, including records;
— assignment of management responsibility;
— provision of adequate resources, including competent human resources and infrastructure;
— control of product provided by external parties;
— identification and traceability of product throughout the process; and
— control of non-conforming product.
NOTE ISO 13485 covers all stages of the lifecycle of medical devices in the context of quality management
systems for regulatory purposes. National and/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.
4.2 A process shall be specified for the calibration of all equipment, including instrumentation for test
purposes, used in meeting the requirements of this document.
5 Requirements
5.1 Unless specified otherwise in this document, the requirements of ISO 11140-1 shall apply.
5.2 Test samples shall be conditioned to 23 °C ± 1 °C and 50 ± 2 % RH prior to testing for performance.
5.3 Conformance with the requirements of this document shall be determined by establishing conformity
with the performance requirements of Clause 7.
5.4 The indicator shall have sufficient strength to withstand steam sterilization and subsequent handling.

ISO/DIS 11140-4:2025(en)
5.5 Test cycles for demonstrating conformance with the requirements of this document shall employ sub-
atmospheric, trans-atmospheric and super-atmospheric air removal stages (see Table 1 and A.1, A.2 and
A.3) except when the indicator, or indicator system, is intended solely for use with one type of air removal
system, in which case only the specified air removal system needs to be used during conformance testing.
5.6 A thermometric recording instrument(s) shall be used in conjunction with temperature sensors to
record the temperatures measured in the locations specified in the tests described in this document. The
temperature-measuring equipment used in all test methods for demonstrating conformance with this
document shall meet the following requirements.
a) Temperature sensors shall be either platinum resistance and conform with Class A of IEC 60751:2022,
5.2.3.1, or a thermocouple and conform with one of the tables of tolerance class 1 of IEC 60584-1:2013,
Clause 5.
b) The performance characteristic of the temperature sensor shall not be affected by the environment in
which it is used, e.g. pressure, steam or vacuum.
c) The temperature sensors shall have a response time in water of Ʈ ≤ 0,5 s.
d) The temperature measured by all temperature sensors when immersed in a temperature source at a
temperature known to within ±0,1 K (±0,1 °C), and within the sterilization temperature band, shall not
differ by more than 0,5 K (0,5 °C).
e) The recording instrument shall record the temperature from a minimum of 6 sensors. The sampling
interval shall not exceed 2,5 s. All data sampled shall be used for the interpretation of results.
f) The scale range shall include 0 °C to 150 °C. For analogue instruments, the minor mark interval shall
not exceed 1 K (1 °C), the resolution shall be not less than 0,5 K (0,5 °C) and the chart speed shall be not
less than 15 mm/min. Digital instruments shall register and record in increments of not more than 0,1 K
(0,1 °C).
g) The limit of error of the recording instrument between 0 °C and 150 °C (excluding temperature sensors)
shall not exceed 0,25 % when tested in an ambient temperature of (20 ± 3) °C. The additional error due
to change in the environmental temperature shall not exceed 0,04 K/K (0,04 °C / °C).
h) Calibration shall be carried out using a working or reference standard that is traceable to a national
standard or a primary standard. The instrument shall have a valid test certificate.
6 Indicator format
6.1 When the indicator is one in which the indicator reagent is distributed on a substrate, it shall meet the
following requirements.
a) The indicator reagent shall be distributed to cover not less than 30 % of the surface area of the substrate.
The distance between adjacent areas of indicator reagent shall not exceed 20 mm.
NOTE This requirement is intended to apply to indicators that are interpreted by an edge to centre
comparison of the indicator.
b) The pattern of indicator reagent distribution should permit clear interpretation of the colour change.
c) The substrate shall have a colour which is uniform to visual observation.
d) The indicator shall have a difference in relative reflectance density of not less than 0,3 between the
colour of the substrate and either the changed indicator reagent or unchanged indicator reagent as
specified by the manufacturer.
Conformance shall be tested in accordance with Annex B.

ISO/DIS 11140-4:2025(en)
6.2 When the indicator depends on migration of the indicator reagent to demonstrate change, the pattern
of indicator reagent distribution before and after use shall permit clear interpretation of the result.
6.3 When the indicator is intended for use with a user-assembled pack, the indicator shall permit writing
in permanent ink to be made legibly on both processed and unprocessed materials. Those markings made
before processing shall remain legible after processing.
6.4 When the indicator is provided by the manufacturer already incorporated into the test load, the
material of either the indicator or the indicator system, as appropriate, shall permit writing to be made after
processing.
7 Performance requirements
7.1 The indicator, when tested in combination with the test load specified by the manufacturer, shall show
a colour change, complete colour change or uniform colour change, conforming with 6.1 c) or complete
reagent distribution conforming with 6.2 after exposure to a non-fault operating cycle in accordance with
ISO 11140-1:2014, 5.8 c), at an exposure time of 3,5 min at 134 °C, or an exposure time of 15 min at 121 °C, or
at any other time/temperature combination specified by the manufacturer when the temperature tolerance
+°15,C
shall be and the time tolerance shall be ±5 s.
0°C
Conformance shall be tested in accordance with Annex D using the steam exposure apparatus. The steam
exposure apparatus shall be operated with the standard test cycles described in Annex A as shown in Table 1.
Indicator systems intended for use only with specific production cycles shall be tested with those specific
cycles only (see ISO 11140-1:2014, 5.7).
It is possible that indicator systems intended to be used over a wide range of sterilization temperatures,
e.g. both for cycles operating at 121 °C and for those operating at 134 °C, will not give the same depth or
intensity of colour change at both temperatures. This should be regarded as in conformance if:
a) all other performance characteristics required by this document are met;
b) the nature of the colour change is unambiguously defined in the instructions for use (see
ISO 11140-1:2014, 5.8).
7.2 The indicator, when tested in combination with the test load specified by the manufacturer, shall show
no colour change, incomplete colour change, uneven colour change or incomplete reagent distribution, in
accordance with ISO 11140-1:2014, 5.8 c), when exposed to a test cycle previously demonstrated to produce
a reference fault condition (a fault response). Exposure to a reference fault condition shall produce a fault
response regardless of the means of creating the reference fault condition, i.e. the system used to produce
the fault may use air retention, air leak or air injection. The test cycles used to generate the reference fault
conditions shall be as shown in Table 1. The chamber reference temperatures and holding times shall include
134 °C for 3,5 min, or 121 °C for 15 min or another time/temperature combination specified by the
+°15,C
manufacturer (see 7.1) when the temperature tolerance shall be and the time tolerance shall be ±5 s.
0°C
Conformance shall be tested in accordance with Annex D.
Conformance with the fault condition reproducibility shall be demonstrated in accordance with Annex E.

ISO/DIS 11140-4:2025(en)
Table 1 — Schedule of test cycles
Standard test cycle of Annex A
A.1    A.2    A.3
Test condition
Sub-atmospheric    Trans-atmospher-    Super-atmospheric
pulsing ic pulsing pulsing
“Pass” cycle (see 6.1) Test required Test required Test required
“Fail” cycle – modified air removal Test required Test required Test not required
stage (see 6.2)
“Fail” cycle – induced leak (see 6.2) Test required Test not required Test not required
“Fail” cycle – air injection (see 6.2) Test required Test not required Test required
7.3 The indicator shall show no discernible colour change after exposure to dry heat at (140 ± 2) °C for not
less than 30 min.
With some indicator systems, the indicator can show a slight colour change after exposure to dry heat;
this shall be acceptable if the change that occurs is slight or markedly different from that brought about
by exposure to steam in accordance with 7.1 and within the limits specified in the instructions for use (see
ISO 11140-1:2014, 5.8).
Conformance shall be tested in accordance with Annex F.
7.4 Indicator systems intended for use only with a sterilization temperature of 121 °C shall be tested by
exposure to dry heat at (130 ± 2) °C for not less than 45 min if the indicator system will not withstand
heating to 140 °C.
Conformance shall be tested in accordance with Annex F.
7.5 Indicators intended for use with reusable user-assembled packs shall not visibly transfer chemical
indicator reagent to the material of the test load during processing. Pre-assembled packs and indicators
intended for use with single-use user-assembled packs shall not transfer chemical indicator reagent to the
material of the test load during processing to an extent which impairs the utility of the product.
Conformance shall be demonstrated by visual examination after testing in accordance with the requirements
of 7.1 and Annex C.
7.6 The indicator system shall conform with the requirements of this document for the duration of the
shelf life specified [see ISO 11140-1:2014, 5.8 j)].
If any change in the indicator occurs during ageing, it shall be different from the change on exposure to
saturated steam (as described in 7.1) and shall either inactivate the indicator so that no further change can
take place or not affect the performance of the indicator with respect to the requirements of 7.1 and 7.2.
Conformance shall be tested in accordance with Annex G.
8 Packaging and labelling
8.1 Each indicator, or indicator system, shall be marked with:
a) the sterilization temperature(s) at which the product is designed to be used (see ISO 11140-1:2014, 5.7);
b) a unique code from which the manufacturing history can be traced [see ISO 11140-1:2014, 5.8 k)];
c) the expiry date under the specified storage conditions [see ISO 11140-1:2014, 5.8 j)];
d) the symbol ISO 11140-4
e) at least the information summarized in Figure 1.

ISO/DIS 11140-4:2025(en)
Adjacent to each heading there shall be a clear space not less than 5 mm × 20 mm for the user to enter the
required information at the time of use or, if the size of the indicator does not permit this, each indicator or
indicator system shall be supplied with a means of retaining the indicator or indicator system as a permanent
record which shall be printed with the information given in Figure 1. The means of retention shall permit
writing in permanent ink to be made in association with the indicator or indicator system.
NOTE This is an example of a suitable format. Other formats and/or text can be used.
Figure 1 — Provision for recording information to be provided on or with each indicator or
indicator system
8.2 When the indicator system is supplied assembled, i.e. with the indicator within the test load, the
test load shall be marked with the sterilization temperature(s) at which the product is suitable for use, the
manufacturer's name, batch number and date of manufacture (see ISO 11140-1:2014, 5.7 and 5.8). In addition,
either a means of uniquely identifying the individual indicator system or an area on the outside of the test
load on to which the operator can write the number of the machine tested and date shall be provided.
When similar products are available which are intended only for specific sterilization cycles, the product
shall include identification sufficient to enable the user to determine, from the instructions for use, any
restrictions on the use of the product. The identification shall be on the indicator or indicator system and, if
not visible to the user before use, shall also be on the outside of the test load.
8.3 The transport package shall be such that the product can be removed easily. The package shall protect
the product to the extent necessary to ensure that the indicator system retains its performance throughout
the stated shelf life when stored in accordance with the instructions for use and product labelling.
Documentary evidence shall be retained demonstrating conformance.
8.4 The outside of each indicator system shall be marked with the sterilization temperature(s) at which
the product is suitable for use.
8.5 The information supplied (see ISO 11140-1:2014, 5.8) shall include sufficient instructions on the use of
the indicator system to enable correct interpretation of the test results.
8.6 When requested by the purchaser, a certificate of conformity to the requirements of this document for
each batch of product supplied shall be available.

ISO/DIS 11140-4:2025(en)
8.7 The information supplied may take the form of internationally recognised symbols. See, for example,
ISO 15223-1.
8.8 The product shall be identified with a unique identification or UDI carrier (see ISO 11140-1:2014, 5.8).

ISO/DIS 11140-4:2025(en)
Annex A
(normative)
Standard test cycles
A.1 Cycle 1: Air removal by sub-atmospheric pulsing
The standard test cycle for sub-atmospheric air removal shall consist of the following steps:
a) evacuation of the chamber to 5,0 kPa;
b) steam admission to 97,0 kPa;
c) repetition of steps a) and b) a further three times;
d) if air injection is being used, it shall take place and be completed during steam admission to the exposure
time at a pressure of between 75 kPa and 105 kPa (indicated by arrow 2 on Figure A.1);
e) steam admission to set operating pressure (see specific requirements for steam admission stage in A.4);
f) exposure time;
g) evacuation to 5,0 kPa;
h) air admission.
The actual pressures achieved at the set points shall be determined by the tolerance permitted for the steam
exposure apparatus (see Annex H).

ISO/DIS 11140-4:2025(en)
Key
1 set operating pressure (kPa)
2 air injection
Figure A.1 — Standard test cycle — Sub-atmospheric air removal
A.2 Cycle 2: Air removal by trans-atmospheric pulsing
The standard test cycle for air removal by trans-atmospheric pulsing shall consist of the following steps:
a) evacuation of the chamber to 5,0 kPa;
b) steam admission to 150 kPa;
c) evacuation of the chamber to 50 kPa;
d) repetition of steps b) and c) a further three times;
e) steam admission to set operating pressure minus 10,0 kPa;
f) evacuation of chamber to 110 kPa to 120 kPa;
g) repetition of steps e) and f) one further time;
h) steam admission to set operating pressure (see specific requirements for steam admission stage in A.4);
i) exposure time;
j) evacuation to 5,0 kPa;
k) air admission.
The actual pressures achieved at the set points shall be determined by the tolerance permitted for the steam
exposure apparatus (see Annex H).

ISO/DIS 11140-4:2025(en)
Key
1 set operating pressure
2 set operating pressure minus 10 kPa
Figure A.2 — Standard test cycle — Trans-atmospheric air removal
A.3 Cycle 3: Air removal by super-atmospheric pulsing
The standard test cycle for air removal by super-atmospheric pulsing shall consist of the following steps:
a) evacuation of the chamber to 5,0 kPa;
b) steam admission to 95 kPa;
c) evacuation of the chamber to 5,0 kPa;
d) repetition of steps b) and c);
e) steam admission to set operating pressure minus 20,0 kPa;
f) evacuation of the chamber to 105 kPa to 120 kPa;
g) repetition of steps e) and f) a further two times;
h) if air injection is being used, it shall take place during steam admission to the exposure time at a pressure
of between 120 kPa and 130 kPa (indicated in Figure A.3);
i) steam admission to set operating pressure (see specific requirements for steam admission stage in A.4);
j) exposure time;
k) evacuation to 5,0 kPa;
l) air admission.
ISO/DIS 11140-4:2025(en)
Key
1 set operating pressure (kPa)
2 set operating pressure minus 20 kPa
3 air injection
Figure A.3 — Standard test cycle — Super-atmospheric air removal
A.4 Acceptance limits during steam admission
A.4.1 The rate of pressure rise during steam admission, to set operating pressure over the range 100 kPa
or lowest pressure at the bottom of the last super-atmospheric pulse to the set operating pressure of the
exposure time, shall be between 100 kPa/min and 250 kPa/min as indicated in Figure A.4.
A.4.2 Select the operating temperature of the exposure time such that it corresponds to the temperature
as stated for the indicator. Set the operating pressure such that it corresponds to a saturated steam
temperature of (selected operating temperature +0,2 °C).
A.4.3 The integral [integrated come-up exposure (ICE)] between the chamber reference temperature
when the chamber reaches 100 kPa, or at the bottom of the last super-atmospheric pulse, whichever is the
greater, and the set temperature during the steam admission period, bounded by the chamber reference
12T
 
R
temperature on the graph, shall not exceed T ⋅
R  
 
where T is the set temperature minus 100 °C.
R
12⋅34
EXAMPLE At a set temperature of 134 °C, the integral shall not exceed 34⋅( )=2312s.K . At a set
12⋅21
 
temperature of 121 °C, the integral shall not exceed 21⋅ =882s.K
 
 
NOTE 1 These limits are intended to ensure that steam admission does not contribute to excessive exposure of the
indicator to atypical conditions. ICE shall be calculated using Formula (A.1):

ISO/DIS 11140-4:2025(en)
t
ICET=−()Tt⋅d (A.1)
∑ 10
t
where
T is the chamber reference temperature at time t, in Celsius;
T is 100 °C or the lowest temperature of the last positive pulse, in Celsius;
dt is 1 s;
t is the time at which chamber reference temperature attains T , in seconds;
0 o
t is the time after t at which the chamber reference temperature, T , attains set operating
1 0 c
temperature, T , e.g. 134 °C, in seconds.
R
NOTE 2 Each of the test cycles described within this Annex consists of three principal stages: air removal, exposure
time (equivalent to the sterilization stage) and evacuation stage. The temperatures attained during the air removal
stage and the duration of the air removal stage can have a significant effect on indicator performance. The cycles
described are not intended to imitate any of the many cycles which are commercially available. They are intended to
provide an overall range of effects within which most commercially available cycles will occur.
Key
()PP−
R 0
1 maximum rate of pressure rise during steam admission
t
1min
2 rate of pressure rise
PP−
()
R 0
3 minimum rate of pressure rise during steam admission
t
1max
4 integrated come-up exposure (ICE): area bounded by T and the curve traced by T over the time t to t
0 c 0 1
t is the come-up time at the minimum allowed rate of pressure rise of 100 kPa/min
1max
t is the come-up time at the maximum allowed rate of pressure rise of 250 kPa/min
1min
p is the pressure of saturated steam, corresponding to the set operating temperature, in kilopascals
R
p is the pressure of saturated steam, corresponding to the temperature T , in kilopascals
o o
T is 100 °C or the lowest temperature of the last positive pulse, in Celsius
o
T is the chamber reference temperature, in Celsius
c
Figure A.4 — Steam admission
ISO/DIS 11140-4:2025(en)
Annex B
(normative)
Estimation of visual difference between colour of the substrate and
of the changed or unchanged indicator system by determination of
relative reflectance density
B.1 Principle
The relative reflectance density of the changed indicator and the substrate shall be determined in accordance
with the method given in B.3.
NOTE This method is based on ISO 5-1, ISO 5-3 and ISO 5-4.
Relative reflectance density, D , is calculated as follows
Rf
DR=−log (C.1)
Rf 10 f
Φ
c
R = (C.2)
f
Φ
ce
where
Φ is the reflected flux from the indicator;
c
Φ� is the reflected flux from the substrate.
ce
To completely define a type of density spectrally, it is necessary to specify the light source, optics and
spectral response of the measuring system.
NOTE This requirement is intended to apply to indicators that are interpreted by an edge to centre comparison of
the indicator.
B.2 Apparatus
B.2.1 Steam exposure apparatus, as specified in Annex H.
B.2.2 Illuminant D with a relative spectral power distribution, as specified in ISO 11664-2:2022,
Clause 5.
NOTE This is regarded as equivalent to average daylight having a correlated colour temperature of approximately
6 500 K.
B.2.3 Photoelectric reflectance photometer, giving within 0,3 % an indicated
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