SIST EN ISO 11140-4:2007

SLOVENSKI STANDARD
SIST EN ISO 11140-4:2007
01-september-2007
1DGRPHãþD
SIST EN 867-4:2001
Sterilizacija izdelkov za zdravstveno nego – Kemijski indikatorji – 4. del: Indikatorji
razreda 2, ki se uporabljajo namesto Bowie-Dickovega preskusa za ugotavljanje
prodiranja pare (ISO 11140-4:2007)
Sterilization of health care products - Chemical indicators - Part 4: Class 2 indicators as
an alternative to the Bowie and Dick-type test for detection of steam penetration (ISO
11140-4:2007)
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 11140-4:2007)
Stérilisation des produits de santé - Indicateurs chimiques - Partie 4: Indicateurs de
classe 2 comme alternative a l'essai de Bowie et Dick pour la détection de la pénétration
de la vapeur (ISO 11140-4:2007)
Ta slovenski standard je istoveten z: EN ISO 11140-4:2007
ICS:
11.080.01 Sterilizacija in dezinfekcija na Sterilization and disinfection
splošno in general
SIST EN ISO 11140-4:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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EUROPEAN STANDARD
EN ISO 11140-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2007
ICS 11.080.01 Supersedes EN 867-4:2000
English Version
Sterilization of health care products - Chemical indicators - Part
4: Class 2 indicators as an alternative to the Bowie and Dick-
type test for detection of steam penetration (ISO 11140-4:2007)
Stérilisation des produits de santé - Indicateurs chimiques - Sterilisation von Produkten für die Gesundheitsfürsorge -
Partie 4: Indicateurs de Classe 2 comme alternative à Chemische Indikatoren - Teil 4: Indikatoren der Klasse 2,
l'essai de Bowie et Dick pour la détection de la pénétration die alternativ zum Bowie-Dick-Test für den Nachweis der
de la vapeur (ISO 11140-4:2007) Dampfdurchdringung verwendet werden (ISO 11140-
4:2007)
This European Standard was approved by CEN on 14 March 2007.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11140-4:2007: E
worldwide for CEN national Members.

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EN ISO 11140-4:2007 (E)



Foreword

This document (EN ISO 11140-4:2007) has been prepared by Technical Committee ISO/TC
198 "Sterilization of health care products" in collaboration with Technical Committee CEN/TC
102 "Sterilizers for medical purposes", 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 September 2007, and conflicting
national standards shall be withdrawn at the latest by September 2007.

This document supersedes EN 867-4:2000.

This document has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements
of EU Directive(s).

The series EN ISO 11140 consists of the following parts under the general title Sterilization of
health care products - Chemical indicators:

 Part 1: General requirements
 Part 3: Class 2 indicator systems for use in the Bowie and Dick-type steam penetration
test
 Part 4: Class 2 indicators as an alternative to the Bowie and Dick-type test for detection of
steam penetration

Attention is drawn to the fact that the series ISO 11140 additionally consists of Part 5: Class 2
indicators for Bowie and Dick-type air removal tests. However, this Part of ISO 11140 will not
be part of the series EN ISO 11140 because CEN/TC 102 decided not to adopt ISO 11140-5
as a European Standard.

In addition, reference is made to EN 867-5 Non-biological systems for use in sterilizers -
Part 5: Specification for indicator systems and process challenge devices for use in
performance testing for small sterilizers type B and type S and to EN ISO 15882 Sterilization
of health care products - Chemical indicators - Guidance for selection, use and interpretation
of results: Both standards are currently being revised under the Vienna Agreement
(ISO/TC 198 lead).

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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United
Kingdom.


Endorsement notice

The text of ISO 11140-4:2007 has been approved by CEN as EN ISO 11140-4:2007 without
any modifications.


2

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INTERNATIONAL ISO
STANDARD 11140-4
Second edition
2007-03-15


Sterilization of health care products —
Chemical indicators —
Part 4:
Class 2 indicators as an alternative to the
Bowie and Dick-type test for detection of
steam penetration
Stérilisation des produits de santé — Indicateurs chimiques —
Partie 4: Indicateurs de Classe 2 comme alternative à l'essai de Bowie
et Dick pour la détection de la pénétration de la vapeur




Reference number
ISO 11140-4:2007(E)
©
ISO 2007

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ISO 11140-4:2007(E)
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ii © ISO 2007 – All rights reserved

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ISO 11140-4:2007(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 General requirements. 3
5 Indicator system format . 4
6 Performance requirements . 4
7 Packaging and labelling. 6
8 Quality assurance. 7
Annex A (normative) Determination of indicator strength during and after steam sterilization . 8
Annex B (normative) Standard test cycles. 10
Annex C (normative) Estimation of visual difference between colour of the substrate and of the
changed or unchanged indicator system by determination of relative reflectance density . 15
Annex D (normative) Determination of uniform colour change on exposure to saturated steam . 19
Annex E (normative) Determination of equivalence of the alternative indicator to the Bowie and
Dick test . 20
Annex F (normative) Determination of reproducibility of fail conditions created in a standard test
pack by air injection, air leak and retained air systems . 22
Annex G (normative) Determination of indicator colour change on exposure to dry heat . 26
Annex H (normative) Determination of shelf life of product. 27
Annex I (normative) Accelerated ageing of test samples . 28
Annex J (normative) Steam exposure apparatus and steam for test purposes. 29
Annex K (normative) Standard test pack. 32
Annex L (normative) Air injection system . 33
Bibliography . 35

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ISO 11140-4:2007(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 11140-4 was prepared by Technical Committee ISO/TC 198, Sterilization of health care products.
This second edition cancels and replaces the first edition (ISO 11140-4:2001) which has been technically
revised.
ISO 11140 consists of the following parts, under the general title Sterilization of health care products —
Chemical indicators:
⎯ Part 1: General requirements
⎯ Part 3: Class 2 indicator systems for use in the Bowie and Dick-type steam penetration test
⎯ Part 4: Class 2 indicators as an alternative to the Bowie and Dick-type test for detection of steam
penetration
⎯ Part 5: Class 2 indicators for Bowie and Dick-type air removal tests
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ISO 11140-4:2007(E)
Introduction
The Bowie and Dick test is a performance test for steam sterilizers for wrapped goods and 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 17665-1. 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 rapid
and even penetration of steam into the test pack. 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 may also be affected by other factors which inhibit
steam penetration. The test does not necessarily demonstrate either achievement of the required temperature
or maintenance of that temperature for the required time to achieve sterilization.
A test pack for the Bowie and Dick test consists of two components:
a) a small standardized test load;
b) a chemical indicator system 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 indicator systems 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 part of ISO 11140.
This part of ISO 11140 specifies the performance of the indicator system in combination with the test load with
which it is intended to be used. The test load may be presented with the indicator system already incorporated
and intended for single use, or it may be intended for multiple use with a new indicator system to be inserted
prior to each use.
The indicator for which the performance is specified in this part of ISO 11140 is intended to indicate when
steam penetration has been inadequate. The performance of the indicator specified in this part of ISO 11140
should be equivalent, but not necessarily identical, to the performance obtained in the Bowie and Dick-type
test as described in ISO 11140-3. Equivalence should be regarded as providing a similar response to steam
penetration with any differences being predictable and such that the necessary level of assurance of
satisfactory steam penetration is provided. An indicator 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.
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INTERNATIONAL STANDARD ISO 11140-4:2007(E)

Sterilization of health care products — Chemical indicators —
Part 4:
Class 2 indicators as an alternative to the Bowie and Dick-type
test for detection of steam penetration
1 Scope
This part of ISO 11140 specifies the performance for a Class 2 indicator 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 complying with this part of ISO 11140 incorporates a specified material which is used as a test
load. This test load may, or may not, be re-usable. This part of ISO 11140 does not specify requirements for
the test load, but specifies the performance of the indicator in combination with the test load with which it is
intended to be used. The indicator specified in this part of ISO 11140 is intended to identify poor steam
penetration but does not necessarily indicate the cause of this poor steam penetration.
This part of ISO 11140 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 referenced documents are indispensable for the application 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 5-1, Photography — Density measurements — Part 1: Terms, symbols and notations
ISO 5-3, Photography — Density measurements — Part 3: Spectral conditions
ISO 5-4:1995, Photography — Density measurements — Part 4: Geometric conditions for reflection density
ISO 187:1990, Paper, board and pulps — Standard atmosphere for conditioning and testing and procedure for
monitoring the atmosphere and conditioning of samples
ISO 2248, Packaging — Complete, filled transport packages — Vertical impact test by dropping
ISO 10012-1, Quality assurance requirements for measuring equipment — Part 1: Metrological confirmation
system for measuring equipment
ISO 11140-1:2005, Sterilization of health care products — Chemical indicators — Part 1: General
requirements
ISO/CIE 10526:1999, CIE standard illuminants for colorimetry
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ISO 11140-4:2007(E)
IEC 60584-2:1982, Thermocouples. Part 2: Tolerances
IEC 60584-2/am1:1989, Amendment 1 — Thermocouples. Part 2: Tolerances
IEC 60751:1983, Industrial platinum resistance thermometer sensors
IEC 60751/am1:1986, Amendment 1 — Industrial platinum resistance thermometer sensors
EN 285:2006, Sterilization — Steam sterilizers — Large sterilizers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11140-1 and the following apply.
3.1
air pocket
concentration of residual, induced or injected air or non-condensable gases in the standard test pack
3.2
chamber reference temperature
temperature measured at a defined reference point within the steam exposure apparatus
NOTE The defined reference point is usually located in the chamber drain or active chamber discharge.
3.3
exposure time
period for which the chamber reference temperature lies within the sterilization temperature band
3.4
pre-assembled pack
indicator in which the indicator system is incorporated into the test load during the manufacturing process and
which is supplied ready for use
3.5
reference fault period
period of 30 s commencing when the chamber reference temperature attains the set operating temperature
3.6
sterilization temperature
minimum temperature of the sterilization temperature band
NOTE 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.
3.7
sterilization temperature band
range of temperatures from the sterilization temperature to the maximum allowable temperature which may
prevail throughout the load during the holding time
NOTE These temperatures are usually stated in whole degrees centigrade.
3.8
temperature depression
thermodynamic temperature difference in kelvin given by (chamber reference temperature, in degrees
centigrade) minus (temperature in the standard test pack, in degrees centigrade)
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ISO 11140-4:2007(E)
3.9
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, within the limits
of accuracy of the temperature-measuring equipment
3.10
user-assembled pack
indicator in which the user combines the indicator system with the test load prior to use
4 General requirements
4.1 The requirements of ISO 11140-1 apply.
4.2 Test samples shall be conditioned in accordance with ISO 187 prior to testing for performance.
4.3 Compliance with the requirements of this part of ISO 11140 shall be determined by establishing
conformity with the performance requirements of Clause 6.
4.4 The indicator shall have sufficient strength to withstand steam sterilization and subsequent handling.
Compliance shall be tested in accordance with Annex A.
4.5 Test cycles for demonstrating compliance with the requirements of this part of ISO 11140 shall employ
sub-atmospheric, trans-atmospheric and super-atmospheric air removal stages (see Table 1 and B.1, B.2 and
B.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 compliance testing.
4.6 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 part of ISO 11140. The
temperature-measuring equipment used in all test methods for demonstrating compliance with this part of
ISO 11140 shall meet the following requirements.
a) Temperature sensors shall be either platinum resistance and comply with Class A of IEC 60751:1983 and
IEC 60751 Amendment 1:1986 or a thermocouple and comply with one of the tables of tolerance class 1
of IEC 60584-2:1982 and IEC 60584-2 Amendment 1:1989.
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 τ u 0,5 s.
90
d) The temperature measured by all temperature sensors when immersed in a temperature source at a
temperature known to within ± 0,1 K, and within the sterilization temperature band, shall not differ by
more than 0,5 K.
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, the resolution shall be not less than 0,5 K 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.
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.
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.
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ISO 11140-4:2007(E)
5 Indicator system format
5.1 When the indicator system 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.
The pattern of indicator reagent distribution should permit clear interpretation of the colour change.
b) The substrate shall have a colour which is uniform to visual observation.
c) The indicator system 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 or unchanged indicator as specified by the
manufacturer.
Compliance shall be tested in accordance with Annex C.
5.2 When the indicator system 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.
5.3 When the indicator system is intended for use with a user-assembled pack, the indicator system 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.
5.4 When the indicator system 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.
6 Performance requirements
6.1 The indicator, when tested in combination with the test load specified by the manufacturer, shall show a
uniform colour change complying with 5.1 c) after exposure to saturated steam at 134 °C for 3,5 min, or at
121 °C for 15 min or at any other time/temperature combination specified by the manufacturer when the
+1,5
⎛⎞
temperature tolerance shall be °C and the time tolerance shall be ± 5 s.
⎜⎟
0
⎝⎠
Compliance 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 B as shown in Table 1.
Indicators intended for use only with specific air removal cycles shall be tested with those specific cycles only
(see 5.7 of ISO 11140-1:2005).
Indicators 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, may not give the same depth or intensity of colour change at both
temperatures. This should be regarded as in compliance if:
a) all other performance characteristics required by this part of ISO 11140 are met;
b) the nature of the colour change is unambiguously defined in the instructions for use (see 5.8 of
ISO 11140-1:2005).
6.2 The indicator shall show no colour change, incomplete colour change, or uneven colour change 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
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ISO 11140-4:2007(E)
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 manufacturer (see 6.1) when the temperature
⎛⎞+1,5
tolerance shall be °C and the time tolerance shall be ± 5 s.
⎜⎟
0
⎝⎠
Compliance shall be tested in accordance with Annex E.
Compliance with the fault condition reproducibility shall be demonstrated in accordance with Annex F.
Table 1 — Schedule of test cycles to be used
Standard test cycle of Annex B
B.1 B.2 B.3
Test condition
Sub-atmospheric Trans-atmospheric Super-atmospheric
pulsing pulsing pulsing
“Pass” cycle (see 6.1) √ √ √
“Fail” cycle – modified air removal stage (see 6.2) √ √ x
“Fail” cycle – induced leak (see 6.2) √ x x
“Fail” cycle – air injection (see 6.2) √ x √
√ = test required;
x = test not required.
6.3 The indicator system shall show no discernible colour change after exposure to
...