EN ISO 20857:2013

SLOVENSKI STANDARD
01-september-2013
6WHULOL]DFLMDL]GHONRY]D]GUDYVWYHQRQHJR6XKDWRSORWD=DKWHYH]DUD]YRM
YDOLGDFLMRLQUXWLQVNRNRQWURORVWHULOL]DFLMVNLKSRVWRSNRY]DPHGLFLQVNH
SULSRPRþNH,62
Sterilization of health care products - Dry heat - Requirements for the development,
validation and routine control of a sterilization process for medical devices (ISO
20857:2010)
Sterilisation von Produkten für die Gesundheitsfürsorge - Trockene Hitze -
Anforderungen an die Entwicklung, Validierung und Lenkung der Anwendung eines
Sterilisationsverfahrens für Medizinprodukte (ISO 20857:2010)
Stérilisation des produits de santé - Chaleur sèche - Exigences pour l'élaboration, la
validation et le contrôle de routine d'un processus de stérilisation pour dispositifs
médicaux (ISO 20857:2010)
Ta slovenski standard je istoveten z: EN ISO 20857:2013
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.

EUROPEAN STANDARD
EN ISO 20857
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2013
ICS 11.080.01
English Version
Sterilization of health care products - Dry heat - Requirements
for the development, validation and routine control of a
sterilization process for medical devices (ISO 20857:2010)
Stérilisation des produits de santé - Chaleur sèche - Sterilisation von Produkten für die Gesundheitsfürsorge -
Exigences pour l'élaboration, la validation et le contrôle de Trockene Hitze - Anforderungen an die Entwicklung,
routine d'un processus de stérilisation pour dispositifs Validierung und Lenkung der Anwendung von industriellen
médicaux (ISO 20857:2010) Sterilisationsverfahren für Medizinprodukte (ISO
20857:2010)
This European Standard was approved by CEN on 5 April 2013.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20857:2013: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 90/385/EEC on Active Implantable Medical Devices .4
Annex ZB (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 93/42/EEC on Medical Devices .5
Annex ZC (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 98/79/EC on in vitro diagnostic medical devices .6

Foreword
The text of ISO 20857:2010 has been prepared by Technical Committee ISO/TC 198 “Sterilization of health
care products” of the International Organization for Standardization (ISO) and has been taken over as EN ISO
20857:2013 by Technical Committee CEN/TC 204 “Sterilization of medical devices” the secretariat of which is
held by BSI.
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 October 2013, and conflicting national standards shall be withdrawn at
the latest by October 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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 Directives.
For relationship with EU Directives, see informative Annex ZA, B and C, which are integral parts of this
document.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 20857:2010 has been approved by CEN as EN ISO 20857:2013 without any modification.
Annex ZA
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 90/385/EEC on Active Implantable Medical
Devices
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association to provide a means of conforming to Essential Requirements of the
New Approach Directive 90/385/EEC on active implantable medical devices.
Once this standard is cited in the Official Journal of the European Union under that Directive and has been
implemented as a national standard in at least one Member State, compliance with the clauses of this
standard given in Table ZA.1 confers, within the limits of the scope of this standard, a presumption of
conformity with the corresponding Essential Requirements of that Directive and associated EFTA regulations.
Table ZA.1 — Correspondence between this European Standard and Directive 90/385/EEC
Clauses of this EN Essential Requirements (ERs) of Qualifying remarks/Notes
Directive 90/385/EEC
4,5,6,7,8,9,10,11,12 7 This relevant Essential Requirement is
only partly addressed in this European
Standard. Packaging for
maintenance of sterility during
transportation and storage are not

covered
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling
within the scope of this Standard.
Annex ZB
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 93/42/EEC on Medical Devices
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association to provide a means of conforming to Essential Requirements of the
New Approach Directive 93/42/EEC on medical devices.
Once this standard is cited in the Official Journal of the European Union under that Directive and has been
implemented as a national standard in at least one Member State, compliance with the clauses of this
standard given in Table ZB.1 confers, within the limits of the scope of this standard, a presumption of
conformity with the corresponding Essential Requirements of that Directive and associated EFTA regulations.
Table ZB.1 — Correspondence between this European Standard and Directive 93/42/EEC
Clauses of this EN Essential Requirements (ERs) of Qualifying remarks/Notes
Directive 93/42/EEC
4,5,6,7,8,9,10,11,12 8.3 This relevant Essential Requirement is
only partly addressed in this European
Standard. Packaging for
maintenance of sterility during
transportation and storage are not
covered
4,5,6,7,8,9,10,11,12 8.4
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling
within the scope of this Standard.
Annex ZC
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 98/79/EC on in vitro diagnostic medical
devices
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association to provide a means of conforming to Essential Requirements of the
New Approach Directive 98/79/EC on in vitro diagnostic medical devices.
Once this standard is cited in the Official Journal of the European Union under that Directive and has been
implemented as a national standard in at least one Member State, compliance with the clauses of this
standard given in Table ZC.1 confers, within the limits of the scope of this standard, a presumption of
conformity with the corresponding Essential Requirements of that Directive and associated EFTA regulations.
Table ZC.1 — Correspondence between this European Standard and Directive 98/79/EC
Clauses of this EN Essential Requirements (ERs) of Qualifying remarks/Notes
Directive 98/79/EC
4,5,6,7,8,9,10,11,12 B.2.3 This relevant Essential Requirement is
only partly addressed in this European
Standard. Packaging for
maintenance of sterility during
transportation and storage are not

covered
4,5,6,7,8,9,10,11,12 B.2.4
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling
within the scope of this Standard.

INTERNATIONAL ISO
STANDARD 20857
First edition
2010-08-15
Sterilization of health care products —
Dry heat — Requirements for the
development, validation and routine
control of a sterilization process for
medical devices
Stérilisation des produits de santé — Chaleur sèche — Exigences pour
l'élaboration, la validation et le contrôle de routine d'un processus de
stérilisation pour dispositifs médicaux

Reference number
ISO 20857:2010(E)
©
ISO 2010
ISO 20857:2010(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2010
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2010 – All rights reserved

ISO 20857:2010(E)
Contents Page
Foreword .v
Introduction.vi
1 Scope.1
1.1 Inclusions.1
1.2 Exclusions.1
2 Normative references.2
3 Terms and definitions .2
4 Quality management system elements.10
4.1 Documentation .10
4.2 Management responsibility .10
4.3 Product realization .10
4.4 Measurement, analysis and improvement — Control of nonconforming product.10
5 Sterilizing agent characterization.11
5.1 Sterilizing agent.11
5.2 Microbicidal effectiveness.11
5.3 Material effects.11
5.4 Environmental considerations.11
6 Process and equipment characterization .11
6.1 Process characterization.11
6.2 Equipment characterization.11
7 Product definition.13
7.1 General.13
7.2 Product safety and performance .13
7.3 Packaging considerations.14
7.4 Microbiological quality.14
7.5 Product family.14
7.6 Biological safety.14
8 Process definition.15
9 Validation.16
9.1 General.16
9.2 Installation qualification .16
9.3 Operational qualification .16
9.4 Performance qualification.16
9.5 Additional sterilization systems .18
9.6 Review and approval of validation .18
10 Routine monitoring and control.19
10.1 Routine control .19
10.2 Routine monitoring .19
10.3 Process monitoring locations.20
11 Product release from sterilization/depyrogenation .21
12 Maintaining process effectiveness.21
12.1 General.21
12.2 Recalibration.21
12.3 Maintenance of equipment .21
12.4 Requalification.21
12.5 Assessment of change .22
ISO 20857:2010(E)
Annex A (informative) Guidance on the application of this International Standard .23
Annex B (informative) Process definition based on inactivation of the microbial population in its
natural state (bioburden-based approach) .46
Annex C (informative) Process definition based on the inactivation of reference microorganisms
and knowledge of bioburden (combined bioburden/biological indicator approach) .48
Annex D (informative) Conservative process definition based on inactivation of reference
microorganisms (overkill method).51
Annex E (informative) Process development .54
Bibliography .57

iv © ISO 2010 – All rights reserved

ISO 20857:2010(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 20857 was prepared by Technical Committee ISO/TC 198, Sterilization of health care products.
ISO 20857:2010(E)
Introduction
A sterile medical device is one that is free of viable microorganisms. International Standards that specify
requirements for development, validation and routine control of sterilization processes, require, when it is
necessary to supply a sterile medical device, that adventitious microbiological contamination of a medical
device prior to sterilization be minimized. Even so, medical devices produced under standard manufacturing
conditions in accordance with the requirements for quality management systems (see, for example,
ISO 13485) may, prior to sterilization, have microorganisms on them, albeit in low numbers. Such products
are non-sterile. The purpose of sterilization is to inactivate the microbiological contaminants and thereby
transform the non-sterile products into sterile ones.
The kinetics of inactivation of a pure culture of microorganisms by physical and/or chemical agents used to
sterilize medical devices can generally best be described by an exponential relationship between the numbers
of microorganisms surviving and the extent of treatment with the sterilizing agent; inevitably this means that
there is always a finite probability that a microorganism may survive regardless of the extent of treatment
applied. For a given treatment, the probability of survival is determined by the number and resistance of
microorganisms and by the environment in which the organisms exist during treatment. It follows that the
sterility of any one product in a population subjected to sterilization processing cannot be guaranteed and the
sterility of a processed population is defined in terms of the probability of there being a viable microorganism
present on a product.
This International Standard describes requirements that, if met, will provide a dry heat sterilization process
capable of sterilizing medical devices through appropriate microbicidal activity. This International Standard
also describes requirements that, if met, will provide a dry heat depyrogenation process through an
appropriate denaturation activity. Furthermore, such compliance permits prediction, with reasonable
confidence, that there is a low probability of there being a viable microorganism present on the product after
processing. Specification of this probability is a matter for regulatory authorities and may vary from country to
country (see for example EN 556-1 and ANSI/AAMI ST67). Additionally, there will be a low probability of
pyrogenic material of bacterial origin being present on the product after the application of a depyrogenation
process.
Generic requirements of the quality management systems for design/development, production, installation and
servicing are given in ISO 9001 and particular requirements for quality management systems for medical
device production in ISO 13485. The standards for quality management systems recognise that, for certain
processes used in manufacturing or reprocessing, the effectiveness of the process cannot be fully verified by
subsequent inspection and testing of the product. Sterilization and depyrogenation are examples of such
processes. For this reason, sterilization and depyrogenation processes are validated for use, the performance
of the processes is monitored routinely, and the equipment is maintained.
Exposure to a properly validated, accurately controlled sterilization process is not the only factor associated
with the provision of reliable assurance that the product is sterile and, in this regard, suitable for its intended
use. Attention is therefore given to a number of factors including:
a) the microbiological status of incoming raw materials and/or components;
b) the validation and routine control of any cleaning and disinfection procedures used on the product;
c) the control of the environment in which the product is manufactured, assembled and packaged;
d) the control of equipment and processes;
e) the control of personnel and their hygiene;
f) the manner and materials in which the product is packaged;
g) the conditions under which product is stored.
vi © ISO 2010 – All rights reserved

ISO 20857:2010(E)
These factors also need consideration for the provision of reliable assurance of depyrogenation.
The type of contamination on the product to be sterilized varies and this variation influences the effectiveness
of a sterilization and depyrogenation process. Product that has been used in a health care setting and is being
presented for resterilization in accordance with the manufacturer's instructions (see ISO 17664) should be
regarded as a special case. There is potential for such product to possess a wide range of contaminating
microorganisms and residual inorganic and/or organic contamination in spite of the application of a cleaning
process. Hence, particular attention has to be given to the validation and control of the cleaning and
disinfection processes used during reprocessing.
The requirements are the normative parts of this International Standard with which compliance is claimed. The
guidance given in the informative annexes is not normative and is not provided as a check list for auditors.
The guidance provides explanations as well as methods that are accepted as being suitable means for
complying with the requirements. Approaches other than those given in the guidance may be used if they are
effective in achieving compliance with the requirements of this International Standard.
The development, validation and routine control of a sterilization process and/or a depyrogenation process
comprise a number of discrete but interrelated activities, for example calibration, maintenance, product
definition, process definition, installation qualification, operational qualification and performance qualification.
While the activities required by this International Standard have been grouped together and are presented in a
particular order, this International Standard does not require that the activities be performed in the order that
they are presented. The activities required are not necessarily sequential, as the programmes of development
and validation might be iterative. It is possible that performing these different activities will involve a number of
separate individuals and/or organizations, each of whom undertake one or more of these activities. This
International Standard does not specify the particular individuals or organizations to carry out the activities.
INTERNATIONAL STANDARD ISO 20857:2010(E)

Sterilization of health care products — Dry heat —
Requirements for the development, validation and routine
control of a sterilization process for medical devices
1 Scope
1.1 Inclusions
1.1.1 This International Standard specifies requirements for the development, validation and routine control
of a dry heat sterilization process for medical devices.
NOTE Although the scope of this International Standard is limited to medical devices, it specifies requirements and
provides guidance that might be applicable to other health care products.
1.1.2 Although this International Standard primarily addresses dry heat sterilization, it also specifies
requirements and provides guidance in relation to depyrogenation processes using dry heat.
NOTE Dry heat is often used for the depyrogenation of equipment, components and health care products and its
effectiveness has been demonstrated. The process parameters for sterilization and/or depyrogenation are time and
temperature. Because the conditions for depyrogenation are typically more severe than those required for sterilization, a
process that has been validated for product depyrogenation will result in product sterility without additional validation.
1.2 Exclusions
1.2.1 This International Standard does not specify requirements for the development, validation and routine
control of a process for inactivating the causative agents of spongiform encephalopathies such as scrapie,
bovine spongiform encephalopathy and Creutzfeldt-Jakob disease.
NOTE See also ISO 22442-1, ISO 22442-2 and ISO 22442-3.
1.2.2 This International Standard does not apply to processes that use infrared or microwaves as the
heating technique.
1.2.3 This International Standard does not detail a specified requirement for designating a medical device
as "sterile."
NOTE Attention is drawn to national or regional requirements for designating medical devices as “sterile.” See, for
example, EN 556-1 or ANSI/AAMI ST67.
1.2.4 This International Standard does not specify a quality management system for the control of all stages
of production of medical devices.
NOTE It is not a requirement of this International Standard to have a complete quality management system during
manufacture, but the elements of a quality management system that are the minimum necessary to control the sterilization
process are normatively referenced at appropriate places in the text (see, in particular, Clause 4). Attention is drawn to the
standards for quality management systems (see ISO 13485) that control all stages of production of medical devices,
including the sterilization process. Regional and national regulations for the provision of medical devices might require
implementation of a complete quality management system and the assessment of that system by a third party.
1.2.5 This International Standard does not specify requirements for occupational safety associated with the
design and operation of dry heat sterilization and/or depyrogenation facilities.
ISO 20857:2010(E)
NOTE Requirements for operational safety are specified in IEC 61010-2-040. Additionally, safety regulations exist in
some countries.
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 10012, Measurement management systems — Requirements for measurement processes and
measuring equipment
ISO 10993-1, Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk
management process
ISO 10993-17, Biological evaluation of medical devices — Part 17: Establishment of allowable limits for
leachable substances
ISO 11138-1:2006, Sterilization of health care products — Biological indicators — Part 1: General requirements
ISO 11138-4:2006, Sterilization of health care products — Biological indicators — Part 4: Biological indicators for
dry heat sterilization processes
ISO 11140-1, Sterilization of health care products — Chemical indicators — Part 1: General requirements
ISO 11607-1, Packaging for terminally sterilized medical devices — Part 1: Requirements for materials, sterile
barrier systems and packaging systems
ISO 11607-2, Packaging for terminally sterilized medical devices — Part 2: Validation requirements for
forming, sealing and assembly processes
ISO 11737-1, Sterilization of medical devices — Microbiological methods — Part 1: Determination of a population
of microorganisms on products
ISO 11737-2, Sterilization of medical devices — Microbiological methods — Part 2: Tests of sterility performed in
the definition, validation and maintenance of a sterilization process
ISO 13485, Medical devices — Quality management systems — Requirements for regulatory purposes
IEC 61010-1, Safety requirements for electrical equipment for measurement, control, and laboratory use —
Part 1: General requirements
IEC 61010-2-040, Safety requirements for electrical equipment for measurement, control and laboratory
use — Part 2-040: Particular requirements for sterilizers and washer-disinfectors used to treat medical
materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
batch
defined quantity of product, intended or purported to be uniform in character and quality, which has been
produced during a defined cycle of manufacture
[ISO/TS 11139:2006, definition 2.1]
2 © ISO 2010 – All rights reserved

ISO 20857:2010(E)
3.2
bioburden
population of viable microorganisms on or in product and/or sterile barrier system
[ISO/TS 11139:2006, definition 2.2]
3.3
biological indicator
BI
test system containing viable microorganisms providing a defined resistance to a specified sterilization
process
[ISO/TS 11139:2006, definition 2.3]
3.4
calibration
set of operations that establish, under specified conditions, the relationship between values of a quantity
indicated by a measuring instrument or measuring system, or values represented by a material measure or a
reference material, and the corresponding values realized by standards
[ISO/TS 11139:2006, definition 2.4]
3.5
change control
assessment and determination of the appropriateness of a proposed alteration to product or procedure
[ISO/TS 11139:2006, definition 2.5]
3.6
chemical indicator
non-biological indicator
test system that reveals change in one or more pre-defined process variables based on a chemical or physical
change resulting from exposure to a process
[ISO/TS 11139:2006, definition 2.6]
3.7
correction
action to eliminate a detected nonconformity
NOTE A correction can be made in conjunction with a corrective action (3.8).
[ISO 9000:2005, definition 3.6.6]
3.8
corrective action
action to eliminate the cause of a detected nonconformity or other undesirable situation
NOTE 1 There can be more than one cause for a nonconformity.
NOTE 2 Corrective action is taken to prevent recurrence whereas preventive action (3.27) is taken to prevent
occurrence.
NOTE 3 There is a distinction between correction (3.7) and corrective action.
[ISO 9000:2005, definition 3.6.5]
ISO 20857:2010(E)
3.9
D value
D value
time or radiation dose required to achieve inactivation of 90 % of a population of the test microorganism under
stated conditions
NOTE 1 For the purposes of this International Standard, D value refers to the exposure time necessary to achieve the
90 % reduction of the population of test microorganisms.
NOTE 2 Adapted from ISO/TS 11139:2006.
3.10
depyrogenation
validated process designed to remove or inactivate pyrogenic material, by a specified quantity, which is
monitored by inactivation of endotoxin
NOTE For the purposes of the depyrogenation process, “inactivation” refers to loss of ability of biological material to
cause a pyrogenic reaction.
3.11
depyrogenation process
series of actions or operations needed to achieve the specified requirements for removal or inactivation of
pyrogens
3.12
establish
determine by theoretical evaluation and confirm by experimentation
[ISO/TS 11139:2006, definition 2.17]
3.13
exposure time
period for which the process parameters are maintained within their specified tolerances
[ISO/TS 11139:2006, definition 2.18]
3.14
F value
microbiological lethality of a sterilization process expressed in terms of the equivalent time, in minutes, at a
temperature of 160 °C with reference to microorganisms with a z value of 20 °C.
NOTE 1 For dry heat, the F value for specific values of sterilization temperature, T, and z is referred to as F . Usually,
H
F is the equivalent time in minutes at 160 °C delivered to product at temperature, T, assuming a z value of 20 °C. F can
H H
be determined by biological (F ) or physical (F ) methods.
Bio phys
NOTE 2 The F for a process at temperature T, where T is other than 160 °C, may be determined by multiplying the

H
lethal rate by the time at temperature T:
F = ∆t × L
H
where
F is the equivalent time in minutes at 160 °C, that has been delivered to the product by the process over time t;
H
∆t is the time in minutes at temperature T;
L is the lethal rate at temperature T.
4 © ISO 2010 – All rights reserved

ISO 20857:2010(E)
3.15
fault
one or more of the process parameters lying outside of its/their specified tolerance(s)
[ISO/TS 11139:2006, definition 2.19]
3.16
fraction positive
quotient derived from the number of positive tests of sterility observed and the total number of tests of sterility
performed (number of positive tests of sterility plus number of negative tests of sterility)
3.17
health care product(s)
medical device(s), including in vitro diagnostic medical device(s), or medicinal product(s), including
biopharmaceutical(s)
[ISO/TS 11139:2006, definition 2.20]
3.18
inactivation
loss of ability of microorganisms to grow and/or multiply
[ISO/TS 11139:2006, definition 2.21]
NOTE For purposes of depyrogenation processes, “inactivation” refers to loss of ability of biologic material to cause a
pyrogenic reaction.
3.19
inoculated carrier
supporting material on or in which a defined number of test microorganisms have been deposited
3.20
installation qualification
IQ
process of obtaining and documenting evidence that equipment has been provided and installed in
accordance with its specification
[ISO/TS 11139:2006, definition 2.22]
3.21
lethal rate
L
expression of inactivation per unit time at temperature, T, expressed in terms of a reference temperature, T
ref
NOTE 1 L is expressed as minutes at the reference temperature, T , per minute at T.
ref
()TT−
ref
NOTE 2 Lethal rate at any temperature can be calculated using the equation L = 10
z
where
T is the delivered temperature;
T is the reference temperature;
ref
z is the change in temperature in degrees Celsius required to change a D value by a factor of 10.
ISO 20857:2010(E)
3.22
medical device
instrument, apparatus, implement, machine, appliance, implant, in vitro reagent or calibrator, software,
material or other related article intended by the manufacturer to be used, alone or in combination, for human
beings for one or more of the specific purpose(s) of
— diagnosis, prevention, monitoring, treatment or alleviation of disease,
— diagnosis, monitoring, treatment, alleviation of or compensation for an injury,
— investigation, replacement, modification or support of the anatomy or of a physiological process,
— supporting or sustaining life,
— control of conception,
— disinfection of medical devices,
— providing information for medical purposes by means of in vitro examination of specimens derived from
the human body
and which does not achieve its primary intended action in or on the human body by pharmacological,
immunological or metabolic means, but which may be assisted in its function by such means
[ISO 13485:2003, definition 3.7]
NOTE This definition has been developed by the Global Harmonization Task Force (GHTF 2002).
3.23
microorganism
entity of microscopic size, encompassing bacteria, fungi, protozoa and viruses
[ISO/TS 11139:2006, definition 2.26]
NOTE A specific standard might not require demonstration of the effectiveness of the sterilization process in
inactivating all types of microorganisms, identified in this definition, for development, validation and/or routine control of the
sterilization process.
3.24
operational qualification
OQ
process of obtaining and documenting evidence that installed equipment operates within predetermined limits
when used in accordance with its operational procedures
[ISO/TS 11139:2006, definition 2.27]
3.25
parametric release
declaration that product is sterile, based on records demonstrating that the process parameters were
delivered within specified tolerances
[ISO/TS 11139:2006, definition 2.29]
3.26
performance qualification
PQ
process of obtaining and documenting evidence that the equipment, as installed and operated in accordance
with operational procedures, consistently performs in accordance with predetermined criteria and thereby
yields product meeting its specification
[ISO/TS 11139:2006, definition 2.30]
6 © ISO 2010 – All rights reserved

ISO 20857:2010(E)
3.27
preventive action
action to eliminate the cause of a potential nonconformity or other undesirable potential situation
NOTE 1 There can be more than one cause for a potential nonconformity.
NOTE 2 Preventive action is taken to prevent occurrence whereas corrective action (3.8) is taken to prevent
recurrence.
[ISO 9000:2005, definition 3.6.4]
3.28
process challenge device
PCD
item designed to constitute a defined resistance to a sterilization process and used to assess performance of
the process
[ISO/TS 11139:2006, definition 2.33]
3.29
process parameter
specified value for a process variable
NOTE The specification for a sterilization process includes the process parameters and their tolerances.
[ISO/TS 11139:2006, definition 2.34]
3.30
process variable
condition within a sterilization process, changes in which alter microbicidal effectiveness
EXAMPLES Time, temperature, pressure, concentration, humidity, wavelength.
[ISO/TS 11139:2006, definition 2.35]
3.31
product
result of a process
[ISO 9000:2005, definition 3.4.2]
NOTE For the purposes of sterilization standards, product is tangible and can be raw material(s), intermediate(s),
sub-assembly(ies) and health care product(s)
3.32
product family
group or subgroup of product characterized by similar attributes such as mass, material, construction, shapes,
lumens and/or packaging and that presen
...