Chemical Indicators (CI) for sterilization control Guide with Terms, Standards and Type identification Information updated: March 2017. References to the standards mentioned DIN EN ISO 11140-1: General requirements for chemical indicators (e.g. for colour change, toxicity, durability) and their type identification (Type 1, 2, 3, 4, 5, 6). DIN EN ISO 11140-3: Requirements for steam penetration test: Bowie-Dick test sheets. DIN EN ISO 11140-4: Requirements for indicators for the steam penetration test as an alternative to the B-D test (7 kg of laundry package): Bowie-Dick Single-use Test Package, Bowie-Dick Helix Test. DIN EN ISO 11140-5: Requirements for indicators for the steam penetration test as an alternative to the B-D test (4 kg of laundry package): valid only for USA. EN ISO 867-5: Requirements for a hollow body PCD (Process Challenge Device = test body). The testing methods are used to test the Batch Monitoring Systems (BMS). DIN EN ISO 15882: Guide for the selection, use and interpretation of results. DIN EN ISO 18472 (formerly DIN EN ISO 11140-2): Specifications for the test equipment that is required for developing and producing indicators in conformance with DIN EN ISO 11140. - 1 -
DIN EN ISO 11140-1: Type Identification Appropriate use Type Category Shows the effect of a procedure to distinguish between non-treated and treated items and/or shows serious errors in a sterilization procedure. 1 Requirements of Effect indicator or Process indicator as per type 1 Indicators for use in specific applications, such as in the Bowie-Dick Type test. Indicators that are arranged inside the individual objects of a load and are used to analyse the attainment of the critical process variables at the site of placement This indicator responds only to one critical process variable. This indicator responds to more than one critical process variable. This indicator responds to all the critical process variables. 2 3 4 5 Special Indicator (e.g. Bowie-Dick) Requirements conforming to ISO 11140-3, ISO 11140-4 and ISO 11140-5 Internal indicator Indicator for a single parameter Requirements as per type 3 Internal indicator Indicator for multiple parameters Requirements as per type 4 Internal indicator Integrated Indicator Requirements as per type 5 This indicator responds to all the critical process variables. 6 Internal indicator Emulating Indicator Requirements as per type 6-2 -
Which indicator type checks which phase of sterilization Use and performance requirements Indicators for air removal and steam penetration (= Type 2) Bowie-Dick Test / BMS Batch Monitoring System (Batch control) Air removal and Steam penetration are checked Requirements and markings (incl. time and temperature requirements) specified in the appropriate standards DIN EN ISO 11140-3 / DIN EN ISO 11140-4 /DIN EN ISO 11140-5 / EN ISO 867-5 must be complied with. - 3 -
Distinction between sterilised and non- sterilised products (= Process Indicator Type 1) For applications with individual objects (e.g. Packages, Containers), process indicators must be designed to indicate that the corresponding unit is directly exposed to the sterilization procedure and to distinguish between treated and untreated objects. With a treatment time of 0.3 minutes (+/- 5 sec) at 134 C (+3/-0 C), the indicator must not show any change. With a treatment time of 2 minutes (+/- 5 sec) at 134 C (+3/-0 C), the indicator must show a distinct change. Indicators for in-package use (= Type 4, 5, 6) Type 4, 5 and 6 indicator strips check the sterilization processes for sufficient steam effect on the inside of the packaging or at other selected points. Various sterile barrier systems within a batch can be independently verified. - 4 -
The accuracy of the PASS/FAIL display increases from type 4 to type 5 to type 6: Type 4: An indicator for multiple critical process variables (= multi-parameter indicator) must be designed so that it responds to two or more of the critical process variables (temperature, humidity) and is intended to display treatment in a sterilization procedure with specified values (SV = stated values) of the selected critical process variables (e.g. 134 C - 5.3 min). With 25% less time or if the temperature is 2 C lower or more, then the indicator must show an error Type 5: An integrated indicator (= Integrator) must be designed so that it responds to all the critical process variables (time, temperature, humidity). The stated values generated are such that the performance requirements match or exceed those stipulated in the ISO 11138 series of standards for biological indicators. With 15% less time or if the temperature is 1 C lower or more, then the indicator must show an error Type 6: An emulating indicator (= Emulator) must be designed so that it responds to all the critical process variables (time, temperature, humidity). The stated values are specified using the process variables of the sterilization procedure or are stipulated by the monitoring authorities (e.g. 134 C - 7 min.). With 6 % less time or if the temperature is 1 C lower or more, then the indicator must show an error - 5 -
DIN EN ISO 18472: Test equipment specifications for developing indicators in conformance with DIN EN ISO 11140 The following devices and components are necessary for developing and manufacturing standardcompliant products. VP stericlin fulfils all these requirements with its own devices. The development and production of standard-compliant indicators is not possible without this test equipment. Resistometer (B.I.E.R. Vessel) - 6 -
Test Sterilizer - 7 -
Feed water quality and Steam quality - 8 -