CEN/TC 102/WG 7 - Biological and chemical indicators

This document specifies the performance requirements and test methods for hollow devices and porous devices as well as the chemical indicators and biological indicators that are utilized within these devices for testing a specific steam penetration performance of type B cycles and some type S cycles of small steam sterilizers according to EN 13060.
NOTE      The hollow and porous devices described in this document are not intended for use as surrogate devices for hollow and porous medical devices used in health care facilities.
a)    Chemical indicators used with a porous device specified in this document are designed to demonstrate the adequacy of steam penetration into a porous device in small steam sterilizers (see EN 13060).
This document specifies the requirements for:
—    a reference porous device (RPD) as a reference device by which alternative porous indicator systems (APISs) can be shown to be equivalent in performance according to this document, i.e. a textile test pack in which steam penetration is judged by thermometric means;
—    an alternative porous chemical indicator system equivalent in performance to the RPD, i.e. an APIS, usually commercially manufactured, of any design.
b)    Chemical indicators used with a hollow load device specified in this document are designed to demonstrate the adequacy of steam penetration into a narrow lumen (previously known as hollow load A) in small steam sterilizers (see EN 13060).
This document specifies the requirements for:
—    a reference hollow device (RHD) used as a reference device in this document, i.e. a lumened device with attached capsule in which steam penetration is judged by inactivation or survival of a specified biological indicator;
—    an alternative hollow device:
—    employing the same specific test load as defined for the RHD and a chemical indicator designed specifically for use in the reference hollow test load, i.e. a lumened device with an attached capsule in which steam penetration is judged by visual examination of a chemical indicator;
—    equivalent in performance to the RHD, i.e. an alternative hollow device, usually commercially manufactured, of any design.

1.1  This document specifies the requirements for a test method to be utilized to establish or confirm a reduced incubation time (RIT) that is shorter than the 7-day reference incubation time specified in 7.3.2 of ISO 11138-1:2017 for biological indicators used to monitor moist heat sterilization processes or ethylene oxide (EO) sterilization processes.
NOTE: For biological indicators used for EO sterilization, the stated RIT is applicable to 100 % EO processes or processes that use EO blends, regardless of the product load.
1.2  This document is applicable to manufacturers of biological indicators (BIs) and to end users of BIs who intend to, if required by their quality system, establish, validate or confirm a RIT.
1.3  This document does not apply to biological indicators used to monitor dry heat, low temperature steam formaldehyde (LTSF) or vaporized hydrogen peroxide (VH2O2) sterilization processes.
NOTE      The method described in this document to establish a RIT for biological indicators used to monitor moist heat or EO sterilization processes has been used extensively for many years. However, there is limited experience in use of this method to establish a RIT for biological indicators used to monitor dry heat, low temperature steam formaldehyde or vaporized hydrogen peroxide sterilization processes. This document, therefore, does not include these sterilization processes.

This document 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.
It does not consider those processes that rely solely on physical removal of microorganisms, e.g. filtration.
It is not applicable to combination processes using, for example, washer-disinfectors or flushing and steaming of pipelines.
It does not specify requirements for the selection and use of biological indicators intended to monitor vaporised hydrogen peroxide processes for isolator and room biodecontamination processes at atmospheric pressure.
It is not applicable to liquid immersion sterilization processes.

ISO 11140-1:2014 specifies general requirements and test methods for indicators that show exposure to sterilization processes by means of physical and/or chemical change of substances, and which are used to monitor the attainment of one or more of the process parameter(s) specified for a sterilization process. They are not dependent for their action on the presence or absence of a living organism.

ISO 11140-3:2007 specifies the requirements for chemical indicators to be used in the steam penetration test for steam sterilizers for wrapped goods, e.g. instruments and porous materials. The indicator for this purpose is a Class 2 indicator as described in ISO 11140-1.
Indicators complying with ISO 11140-3:2007 are intended for use in combination with the standard test pack as described in EN 285. ISO 11140-3:2007 does not consider the performance of the standard test pack, but does specify the performance of the indicators.

ISO 11140-4:2007 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).
An indicator complying with ISO 11140-4:2007 incorporates a specified material which is used as a test load. This test load may, or may not, be re-usable. ISO 11140-4:2007 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 ISO 11140-4:2007 is intended to identify poor steam penetration but does not necessarily indicate the cause of this poor steam penetration.
This part of ISO 11140-4:2007 does not include test methods to establish the suitability of these indicators for use in sterilizers in which the air removal stage does not include evacuation below atmospheric pressure.

This European Standard specifies the performance requirements and test methods for non-biological indicator systems, including the process challenge devices within which they are intended to function, to be used for testing the steam penetration performance of small steam sterilizers, Type B or Type S where ap-propriate. The test systems specified are intended for use only in small steam sterilizers Type B conforming to prEN 13060-2 and having a usable chamber space greater than 10 l and for small steam sterilizers Type S conforming to prEN 13060-4 also having a usable chamber space greater than 5 l.
Non-biological indicator systems and the associate process challenge devices are specified for various types of load. The possible loads are considered in two classes: Porous loads, which can be wrapped or unwrapped, or hollow instrument loads, which also can be wrapped or unwrapped.
The relevant section of this European Standard on porous loads specifies the requirements for:
- a standard process challenge device to be used in the small load test for porous loads in small steam sterilizers;
- an indicator system for use in the porous load process challenge device. An indicator for this purpose is a Class B indicator as described in EN 867-1.
- an indicator employing an alternative process challenge device equivalent to the porous load process challenge device.
The relevant section of this European Standard on hollow instruments specifies the requirements for:
- hollow load process challenge devices to be used to simulate hollow instrument loads as defined in prEN 13060-4;
- an indicator system, for use in one of the hollow load process challenge device, for assessing steam penetration in a wrapped load of hollow instruments. An indicator for this purpose is a Class B indicator as described in EN 867-1.
The process challenge devices described in this standard are intended for use only in sterilizers of sufficient size to accommodate the proces

ISO 14161:2009 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.
ISO 14161:2009 applies to biological indicators for which International Standards exist.

ISO 11140-1:2005 specifies general requirements and test methods for indicators that show exposure to sterilization processes by means of physical and/or chemical change of substances, and which are used to monitor the attainment of one or more of the variables required for a sterilization process. They are not dependent for their action on the presence or absence of a living organism.
The requirements and test methods of ISO 11140-1:2005 apply to all indicators specified in subsequent parts of ISO 11140, unless the requirement is modified or added to by a subsequent part, in which case the requirement of that particular part will apply.

This document provides guidance for the selection, use and interpretation of results from application of biological indicators in the development, validation and routine monitoring of sterilization processes. This document applies to biological indicators for which International Standards exist (see ISO 11138 series).

This document provides guidance for the selection, use and interpretation of results of non-biological indicator systems to monitor sterilization processes employing steam, ethylene oxide, irradation, steam-formaldehyde or dry heat. This standard applies to non-biological indicator systems for which  International standards exist (see ISO 11140 series).

This European Standard specifies the performance requirements for a Class B indicator to be used as an alternative
to the Bowie and Dick test for steam sterilizers for wrapped goods (instruments etc. and porous loads). An indicator complying with this European Standard incorporates a specified material which is used as a test load. This test load may, or may not, be re-usable. This European standard does not specify requirements for the test load but specifies the performance of the indicator system in combination with the test load with which it is intended to be used. The indicator specified in this European standard is intended to identify poor steam penetration but does not indicate necessarily the cause of this poor steam penetration. The Bowie and Dick Test is performed to demonstrate conformance of a steam sterilizer for wrapped goods to EN 285 and may be used as a routine test of performance of such a sterilizer (see EN 554). The method of carrying out the test is described in EN 285. This European standard does not include test methods to establish the suitability of these indicators for use in sterilizers in which the air removal stage does not include evacuation below atmospheric pressure.

TC - Wrong translation of a clause

This European standard specifies the requirements for an indicator to be used in the Bowie and Dick test for Steam sterilizers for wrapped goods, eg. instruments and porous materials. An indicator for this purpose is a Class B indicator as described in Part 1 of this standard.

This part of EN 866 specifies requirements for self-contained biological indicator systems intended for use in the routine monitoring of the performance of sterilizers employing ethylene oxide gas as the sterilant. These are intended for use in sterilizers employing pure ethylene oxide or admixtures of the gas with diluent gases, over a sterilizing temperature range of 20 °C to 65 °C.

This part of EN 866 specifies requirements for inoculated carriers and biological indicators intended for use in assessing the performance of dry heat sterilizers operating at temperatures in the range 140° C to 250° C. Note: The indicators specified in this standard are not suitable for assessing depyrogenation processes.

This part of EN 866 specifies requirements for self-contained biological indicator systems intended for use in monitoring the performance of moist heat sterilizers operating at temperatures in excess of 100°C. Note 1: EN 285 specifies the performance and test requirements for large steam sterilizers for porous loads and wrapped goods.

This part of EN 866 specifies requirements for inoculated carriers and biological indicators intended for use in assessing the performance of sterilizers employing low temperature steam and formaldehyde as the sterilant over a sterilizing temperature range of 55° C to 80° C.

TC - Wrong translation of a clause

This part of EN 866 specifies requirements for inoculated carriers and biological indicators intended for use in assessing the performance of sterilizers employing ethylene oxide gas as the sterilant. These are intended for use in sterilizers employing pure ethylene oxide gas or admixtures of the gas with diluent gases, over a sterilizing temperature range of 20°C to 65°C.

This part of EN 866 specifies requirements for inoculated carriers and biological indicators intended for use in assessing the performance of moist heat sterilizers operating at temperatures in excess of 100° C. Note: EN 285 specifies the performance and test requirements for large steam sterilizers for wrapped goods and porous loads.

This part of EN 866 specifies general requirements for the manufacture of biological systems to be used in testing sterilizers. The requirements of this part of EN 866 apply to all biological systems specified in subsequent Parts of EN 866, unless the requirement is modified or added to by a subsequent Part, in which case the requirement of the particular Part will apply.

This part of EN 867 specifies requirements for steam, ethylene oxide, irradiation, dry heat and steam/formaldehyde sterilisation process indicators intended for use with individual packs of product to demonstrate that the pack has been exposed to the process. They may be designed to react to one or more of the critical process variables but may be designed to achieve their end-point reaction after exposure to sub-optimal levels of the process variable. Process indicators have a defined end-point reaction.

This part of EN 867 specifies general requirements for indicators which are not dependent for their action on the presence or absence of living organismes, and which are used to monitor the presence or attainment of one or more of the variables required for a satisfactory sterilisation process. This standard does not specify requirements for the use of biological systems.

This part of EN 866 specifies requirements for inoculated carriers and biological indicators intended for use in assessing the performance of irradiation sterilizers. These are intended for use in sterilizers employing an electron beam or gamma irradiation. They are not intended for use with absorbed doses greater than 45 kGy.