EN ISO 14161:2000

SLOVENSKI STANDARD
SIST EN ISO 14161:2001
01-november-2001
Sterilizacija izdelkov za zdravstveno nego - Biološki indikatorji - Navodilo za izbiro,
uporabo in predstavitev rezultatov (ISO 14161:2000)
Sterilization of health care products - Biological indicators - Guidance for the selection,
use and interpretation of results (ISO 14161:2000)
Sterilisation von Produkten für die Gesundheitsfürsorge -Biologische Indikatoren -
Leitfaden für die Auswahl, Verwendung und Interpretation von Ergebnissen (ISO
14161:2000)
Stérilisation des produits de santé - Indicateurs biologiques - Directives générales pour la
sélection, l'utilisation et l'interprétation des résultats (ISO 14161:2000)
Ta slovenski standard je istoveten z: EN ISO 14161:2000
ICS:
11.080.01 Sterilizacija in dezinfekcija na Sterilization and disinfection
splošno in general
SIST EN ISO 14161:2001 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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INTERNATIONAL ISO
STANDARD 14161
First edition
2000-10-01
Sterilization of health care products —
Biological indicators — Guidance for the
selection, use and interpretation of results
Stérilisation des produits de santé — Indicateurs biologiques — Directives
générales pour la sélection, l'utilisation et l'interprétation des résultats
Reference number
ISO 14161:2000(E)
©
ISO 2000

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ISO 14161:2000(E)
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ii © ISO 2000 – All rights reserved

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ISO 14161:2000(E)
Contents Page
Foreword.v
Introduction.vi
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 General.4
5 Characteristics of biological indicators .6
5.1 General.6
5.2 Test organism suspension for direct inoculation of products .6
5.3 Inoculated carriers.7
5.4 Biological indicators .7
6 Selection of supplier .8
6.1 General.8
6.2 Documentation.9
7 Biological indicators in process development.10
7.1 General.10
7.2 Reference microorganism method .11
7.3 Combined biological indicator and bioburden method.11
7.4 Bioburden method.12
8 Biological indicators in sterilization validation .13
8.1 General.13
8.2 Placement and handling of biological indicators.13
8.3 Sterilizer qualification .13
8.4 Performance qualification.13
8.5 Review and approval of validation.14
8.6 Requalifications .14
9 Biological indicators in routine monitoring .14
9.1 General.14
9.2 Placement and handling of biological indicators.14
9.3 Process challenge device (PCD).15
10 Results .15
10.1 General.15
10.2 Interpretation of results .15
11 Application of biological indicator standards .16
11.1 General assessment of biological indicator performance by the user.16
11.2 Nominal population of test organism .17
11.3 D-value determination .17
11.4 Testing equipment.19
12 Culture conditions .20
12.1 General.20
12.2 Incubation temperature.20
12.3 Incubation period.20
12.4 Choice of growth medium.21
13 Third-party requirements .21
13.1 General.21
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ISO 14161:2000(E)
13.2 Minimum requirements for replicates and total number of biological indicators.22
13.3 Test equipment .22
14 Personnel training .22
15 Storage and handling .23
16 Disposal of biological indicators .23
Annex A (informative) Microbiological inactivation kinetics and enumeration techniques.24
Annex B (informative) Process challenge devices .28
Annex C (informative) Formulae for fraction negative methods for D-value calculations .29
Annex D (informative) Examples of documentation of biological indicators collected by the user .35
Bibliography .39
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ISO 14161:2000(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 3.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 14161 was prepared by Technical Committee ISO/TC 198, Sterilization of health care
products.
Annexes A, B, C and D of this International Standard are for information only.
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ISO 14161:2000(E)
Introduction
This International Standard provides guidance regarding the selection, use and interpretation of results of biological
indicators when used to develop, validate and monitor sterilization processes. The procedures described in this
document are of a general nature and do not, of themselves, constitute a comprehensive development, validation,
or monitoring programme with regard to the sterilization of health care products. The intent of this International
Standard is not to mandate the use of biological indicators in a process, but, if they are used, to provide guidance
for their proper selection and use, to avoid misleading results.
Biological indicators are not intended for use in any process other than that specified by the manufacturer on the
product labelling. The use of an inappropriate biological indicator can give misleading results. In this International
Standard, the user will find guidance on selection of the correct biological indicator for their particular sterilization
process and critical parameters as well as guidance on its appropriate use.
The user should select a biological indicator that is appropriate for the particular process to be employed. There are
wide variations in sterilization processes and biological indicator manufacturers are not able to foresee all possible
uses of their product. Manufacturers, therefore, label biological indicators according to their intended use. It is the
responsibility of the users of biological indicators to select, use, recover and interpret the results as appropriate for
the particular sterilization process used.
Biological indicators should always be used in combination with physical and/or chemical measurements in
demonstrating the efficacy of a sterilizing process. When a physical and/or chemical variable of a sterilization
process is outside its specified limits, cycle parameters should be evaluated. It should be noted that
measurements, which need to be evaluated, may be made during the cycle in the context of the overall cycle.
Systems and/or procedures should be established to evaluate any deviations from the cycle process limits, and
reasons for accepting any deviation should be fully documented.
The performance of a biological indicator can be adversely affected by the conditions of storage and transport prior
to its use, the use of the biological indicator, the sterilizer operating parameters, or the techniques employed after
exposure to the process. For these reasons, the recommendations of the biological indicator manufacturer for
storage and use should be followed. After exposure, biological indicators should be aseptically transferred and
subjected to the validated recovery conditions as specified by the biological indicator manufacturer.
It should be noted that biological indicators are not intended to indicate that the products, nor any other load being
sterilized, are sterile. Biological indicators are utilized to test the effectiveness of a given sterilization process and
employed equipment by assessing microbial lethality according to the concept of sterility assurance level. Suitably
trained personnel should conduct these studies.
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INTERNATIONAL STANDARD ISO 14161:2000(E)
Sterilization of health care products — Biological indicators —
Guidance for the selection, use and interpretation of results
1 Scope
This International Standard provides guidance for the selection, use and interpretation of results from application of
biological indicators when used in the development, validation and routine monitoring of sterilization processes.
This International Standard applies to biological indicators for which International Standards exist.
NOTE 1 See for example the ISO 11138 series.
NOTE 2 The general information provided in this International Standard may have useful application for processes and
biological indicators not currently addressed by existing International Standards, e.g. new and developing sterilization
processes.
This International Standard does not consider those processes that rely solely on physical removal of
microorganisms, e.g. filtration.
This International Standard is not intended to apply to combination processes, using for example washer
disinfectors or flushing and steaming of pipelines.
This International Standard is not intended to apply to liquid sterilization processes.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to apply. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 11134:1994, Sterilization of health care products — Requirements for validation and routine control —
Industrial moist heat sterilization.
ISO 11135:1994, Medical devices — Validation and routine control of ethylene oxide sterilization.
ISO 11138-1:1994, Sterilization of health care products — Biological indicators — Part 1: General.
ISO 11138-2:1994, Sterilization of health care products — Biological indicators — Part 2: Biological indicators for
ethylene oxide sterilization.
ISO 11138-3:1995, Sterilization of health care products — Biological indicators — Part 3: Biological indicators for
moist heat sterilization.
ISO 11737-1:1995, Sterilization of medical devices — Microbiological methods — Part 1: Estimation of population
of microorganisms on product.
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ISO 14161:2000(E)
ISO 13683:1997, Sterilization of health care products — Requirements for validation and routine control of moist
heat sterilization in health care facilities.
ISO 14937, Sterilization of health care products — General criteria for characterization of a sterilizing agent and
development, validation and routine control of a sterilization process.
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1
accreditation
procedure by which an authoritative body gives formal recognition that a body or person is competent to carry out
specific tasks
NOTE 1 See reference [3].
NOTE 2 Accreditation does not itself qualify the laboratory to approve any particular product. However, accreditation may be
relevant to approval and certification authorities when they decide whether or not to accept data produced by a given laboratory
in connection with their own activities.
3.2
aseptic technique
conditions and procedures used to exclude the introduction of microbial contamination
3.3
bioburden
population of viable microorganisms on or in a product and/or package
3.4
biological indicator
BI
inoculated carrier contained within its primary pack ready for use and providing a defined resistance to the
specified sterilization process
NOTE See ISO 11138-1.
3.5
D-value
D value
10
time or radiation dose required to achieve inactivation of 90 % of a population of the test microorganism under
stated exposure conditions
NOTE See ISO 11138-1.
3.6
inoculated carrier
carrier on which a defined number of test organisms have been deposited
NOTE 1 See ISO 11138-1.
NOTE 2 The carrier is the supporting material on which test organisms are deposited.
NOTE 3 The test organism is a microorganism used for the manufacture of inoculated carriers.
3.7
inoculation
transferral of a defined microbial entity into or on an item
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ISO 14161:2000(E)
3.8
log reduction
LR
reduction in number of viable microorganisms, expressed in log units, after fractional exposure to a sterilization
10
cycle
3.9
process challenge device
PCD
item which is deemed to present one of the greatest challenges to the effective performance of the sterilizing
agent(s) in the collection of items to be sterilized
NOTE 1 The item is so constituted that a biological indicator can be placed in the position that is most difficult for the
sterilizing agent to reach.
NOTE 2 The design of the process challenge device depends on the type of goods to be sterilized and the sterilization
procedure.
NOTE 3 The biological indicator should not interfere with the function of the process challenge device.
NOTE 4 In some process challenge devices an inoculated carrier may be used in place of a biological indicator.
3.10
process challenge location
PCL
site that simulates “worst case” conditions as they are given for sterilizing agent(s) in the goods to be sterilized
NOTE 1 The site is so constituted that a biological indicator can be placed in the position that represents a rigorous
challenge for the sterilizing agent to reach.
NOTE 2 The site depends on the type of goods to be sterilized and the sterilization process parameters.
NOTE 3 The biological indicator should not interfere with the function of the goods.
NOTE 4 In some sites an inoculated carrier may be used in place of a biological indicator.
3.11
process parameter
specified value for a process variable
NOTE Specifications for a sterilization process include the process parameters and their tolerances.
3.12
resistometer
equipment designed to create defined combinations of the physical and/or chemical variables of a sterilization
process within defined limits
NOTE 1 See ISO 11138-1.
NOTE 2 Also referred to as Biological Indicator Evaluator Resistometer (BIER).
3.13
sterilization cycle development
procedure for determination of the appropriate processing parameters and conditions which are consistent with
attaining the desired specifications and label claims for a given product or group of products
3.14
sterilization cycle validation
documented procedure for obtaining, recording and interpreting the results required to establish that a process
would consistently yield product complying with predetermined specifications
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ISO 14161:2000(E)
3.15
sterile
free from viable microorganisms
3.16
sterilization
validated process used to render a product free from viable microorganisms
NOTE In a sterilization process, the nature of microbial inactivation is described by an exponential function. Therefore, the
presence of viable microorganisms on any individual item can be expressed in terms of probability. While this probability may be
reduced to a very low number, it can never be reduced to zero.
3.17
supplier
organization that provides a product to the customer
NOTE 1 In a contractual situation, the manufacturer may be called the “contractor”.
NOTE 2 The supplier may be, for example, the manufacturer, distributor, vendor, importer, assembler or service
organization. The supplier can be either external or internal to the organization. The supplier is a person or business concern
that manufactures goods or owns a factory and represents the “first party” (see reference [4]).
3.18
third party
person or body that is recognized as being independent of the parties involved, as concerns the issue in question
NOTE 1 See reference [1].
NOTE 2 Parties involved are usually supplier (“first party”) and purchaser (“second party”) interests.
3.19
user
person or body employing biological indicators for a given purpose
NOTE 1 See reference [4].
NOTE 2 The user is the customer who is the recipient of a product provided by the supplier (see reference [4]). In a
contractual situation, the user is called “purchaser”. The user may be the customer, beneficiary or purchaser. The user can be
either external or internal to the organization and represents the “second party”.
3.20
z-value
the change in exposure temperature which corresponds to a 10-fold change in
D-value
NOTE See ISO 11138-3.
4 General
This guidance International Standard provides information on biological indicators that may apply generally for any
sterilization process, including new sterilization processes not yet covered by International Standards.
The use of biological indicators is normally documented in procedures and/or instructions.
NOTE Employing quality systems complying with ISO 13485 or ISO 13488 satisfies this provision (see references [11] and
[12]).
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ISO 14161:2000(E)
Biological indicators that are defined in ISO 11138-1, ISO 11138-2 and ISO 11138-3 give requirements for the
manufacture of biological indicator systems where the biological component is a microorganism, such as a bacterial
endospore or other microbiological form. The ISO 11138 series gives requirements for biological indicators for use
in sterilization processes. These International Standards require that suitably trained personnel carry out the
procedures and methods described.
A suitable biological indicator consists of carrier material and packaging, and has a microbiological component that
is known to be suitable for handling without special containment facilities. The growth conditions should be well
documented and the use of the indicator should be as simple and well described to the user as possible to avoid
misinterpretation.
No formal approval system exists internationally for biological indicators that are marketed and used for stated
purposes or under stated conditions. Some national regulatory authorities, however, have particular requirements
for biological indicators and for the choice and use of biological indicators for the validation and control of products
marketed as sterile or sterilized.
A biological indicator represents a microbiological challenge to a sterilization process, and is used to verify that a
sterilization process has the ability to inactivate microorganisms that have a known resistance to a referenced
sterilization process. Test organisms employed in biological indicators typically have resistance to sterilization
which exceeds that of common bioburden microorganisms, although some organisms may exhibit a resistance to
sterilization in excess of that of the test organisms. The appropriate biological indicator has a combination of
population and resistance that exceeds that of the bioburden. If there is reason to believe that the goods to be
processed may be contaminated with particularly resistant organisms, extended sterilization processing, based on
the bioburden, may be required.
The user should ensure that the biological indicator has been validated for use with the particular range of
sterilization conditions that are used. This may require additional information than that given in the labelling. When
biological indicators are used outside reference conditions, the user may require information on the reaction to be
expected from the indicator, e.g. the effect of sub-optimal moisture conditions on the biological indicators used in
an ethylene oxide process. Users who employ biological indicators for non-standard sterilization techniques should
thoroughly characterize the resistance of the biological indicators to the particular sterilization process as compared
to a wide range of microorganisms, including any hazardous microorganisms or infectious agents that may
constitute a part of the bioburden of the product. The relationship of the response of the biological indicator to
process parameters should be clearly demonstrated.
It is incumbent upon those responsible for the sterilization of product to ensure that the type of biological indicator
employed to validate and/or routinely monitor a given sterilization process is appropriate for that use.
The manufacturer’s recommendations for the use and storage of the biological indicators should always be
followed. Failure to do so may compromise the integrity of the biological indicator. If the user removes the
inoculated carrier from the biological indicator’s primary packaging, changes in the resistance characteristics may
occur. Guidance should be sought from the manufacturer on the extent of this change or the user may evaluate
changes in the resistance characteristics. The user should document that the performance characteristics of the
inoculated carrier are appropriate for their use.
Biological indicators should not be used beyond the expiration date stated by the manufacturer.
Those who employ biological indicators for validation and/or routine monitoring of sterilization should
...