Abstract
A big point in standardization work of chemical indicators is the point that turned classification into six kinds according to performance (include a form). And a condition to change in a color after processing (endpoint) according to class including any kind of stated value (±).
1) Class 1: Process indicators It is a process indicator for so-called distinction, assortment. As a form, an indicator printed in sterilization back, indicator tape, indicator label are in this category. 2) Class 2: Indicators for use in specific tests Class 2 Bowie & Dick type indicators are intended to demonstrate the rapid and even penetration of steam and by implication the adequacy of air removal. (ISO 11140-3, 11140-4, 11140-5) 3) Class 3: Single parameter indicators A single parameter indicator shall be designed for one of the critical parameters (for example, high pressure steam sterilization, temperature of saturated steam). 4) Class 4: Multi-parameter indicators A multi-parameter indicator shall be designed for two (for example, EO sterilization, temperature and Gas conc.) or more of the critical parameters. 5) Class 5: Integrating indicators A 1 rank becomes of higher quality than Multi-parameter indicators with a thing reacting to all critical parameters (an indicator doing reaction in consideration of D value). 6) Class 6: Emulating indicators This is a thing reacting to all critical parameters, but it is it the highest-level indicator because standard width is smaller than integrating indicators. Please show Class 3 to 6 as follows, but it is reference in ISO 11140-1 about a detailed standard value.
