biological indicator

What are chemical indicators
and why are they used?

Chemical indicators (CIs), as defined by the Association for the Advancement
of Medical Instrumentation (AAMI) and International Organization for
Standardization (ISO), are devices used to monitor the presence or attainment
of one or more of the parameters required for a satisfactory sterilization process
or used in a specific test of sterilization equipment. For example, when placed
inside packs, chemical indicators are used to confirm that sterilant achieved
good penetration in the items being sterilized.
When chemical indicators are used as part of a comprehensive quality control
program, they can capture failures, such as malfunctioning equipment and
technician errors, that could result in a non-sterile device. The use of chemical
indicators in sterilization provides confidence in the effective reprocessing of
medical devices.