The News Room

The Association for the Advancement of Medical Instrumentation (AAMI) has released an updated edition to a standard that provides guidance on using chemical indicators, which are used to ensure that instruments are sterilized appropriately.

Updated for the first time in 5 years, ANSI/AAMI/ISO 15882, Sterilization of health care products — Chemical indicators — Guidance for selection, use and interpretation of results, has been modified to include new requirements for Class 5 indicators.            

These requirements bring the standard in line with ANSI/AAMI/ISO 11140-1, Sterilization of health care products — Chemical indicators — Part 1: General requirements. Other changes relate to the test equipment used for indicators and the addition of vaporized hydrogen peroxide indicators.

Chemical indicators are used to detect any problems within the sterilization process and for various sterilization methods such as ethylene oxide (EO), steam, or irradiation. “Chemical indicators can be calibrated to be specific for their intended applications, and give immediate results,” says Richard Bancroft, development and technical service director for U.K.-based Albert Browne Ltd., a subsidiary of STERIS, and convener of ISO Technical Committee 198/Working Group 6, which developed the standard. “Their small size can allow placement where some biological indicators and physical probes could not be placed, or would compromise the load packaging.”

Chemical indicators are divided into classes to suit different monitoring needs. “At their most simple, Class 1 indicates visually whether a load has been processed or not,” Bancroft says. “Some chemical indicators (Class 5 and 6) monitor all critical parameters of sterilization.”

The basic performance of any chemical indicator can be measured by its visible change, graduated response or “endpoint” response, which is the point of change that occurs after the indicator has been exposed.

Choosing the Right Class

Chemical indicators are divided into classes to suit different monitoring needs. Below are some questions healthcare professionals should ask to determine which class of indicator they need:

• What characterizes effective sterilization?
• What are the performance characteristics of the indicator?