Sterilization indicators

Sterilization indicators are used to validate and verify sterilization processes and are divided into biological and chemical depending on the purpose.

For biological indicators, the aim is to evaluate the effectiveness of the sterilization process, i.e. the killing of microorganisms in the vegetative or spore phase.

For chemical indicators the purpose is to highlight the application of the sterilization process or to verify the achievement of the critical parameters of the sterilization process.

Biological indicators of sterilization

They consist of standardized bacterial spores inoculated onto different types of support which, in addition to allowing their appropriate use, emulate the process that leads to the reduction of the microbial load.

Bacterial spores used in biological indicators are selected by type, population and resistance to specific sterilizing agents, such as steam, ethylene oxide, hydrogen peroxide, dry heat, chlorine dioxide radiation, formaldehyde etc.

They are available in various forms, such as strips, disks, glass ampoules, self-contained systems, spore suspensions, etc.

They are regulated by ISO 11138 Sterilization of health care products - Biological indicators and by pharmacopoeias.

Chemical and process indicators

These are a wide variety of indicators based on the reactivity of inks that change color when subjected to sterilization processes.

They can be used to distinguish items subjected to sterilization from those not subjected to sterilization, for carrying out specific tests such as the Bowie-Dick test, or for evaluating the achievement of the critical parameters of the sterilization process at the positioning point.

They are available in various forms, such as strips, adhesive labels, sheets, devices, etc.

They are regulated by ISO 11140-1 Sterilization of health care products - Chemical indicators.