The Role of Chemical Indicators in Load Release

Chemical indicators (or CIs) are a necessary part of any healthcare facility’s sterility assurance program. Since the introduction of the Bowie and Dick Test in 1969, the use of chemical indicators has expanded to cover a wide range of sterilization and high-level disinfection monitoring applications.

Learn more about CIs in the article, What is a Chemical Indicator?

When used correctly, chemical indicators can quickly identify errors and help prevent the use of improperly processed instruments in medical procedures. CIs are also necessary for any sterilization process to meet many standards and guidelines for reprocessing. 

What role do Chemical Indicators have when deciding if a load can be released? 

No single product can determine if a load is sterile or safe for release, so policies and procedures need to be built upon a robust quality assurance program with multiple components working together.

Healthcare facilities utilize different tools when determining if a load is safe to release and chemical indicators are just one of those tools.

In addition to interpreting the chemical indicators, Sterile Processing Technicians must review the sterilizer tape to ensure cycle parameters have been met as well as incubate and interpret results from any biological indicators.

There are three primary types of CIs used help determine if a load can be released:

Bowie-Dick Tests

Bowie-Dick tests indicate if a prevacuum steam sterilizer is functioning properly and should be performed daily per ANSI/AAMI ST79 standards.¹ If a Bowie-Dick failure occurs, use our Troubleshooting Guide to help understand why a failure may have occurred.

External Chemical Indicators

External CIs indicate if the packs were exposed to the sterilization process. For example, the VERIFY VH202 Indicator Tape will undergo a color change from pink to peach, yellow or lighter showing that the pack has been processed through a sterilization cycle.

Internal Chemical Indicators

Internal CIs indicate if the internal indicator was exposed to the critical variables of the sterilization process. Internal CIs are required to be placed in every package, tray and rigid container.¹

Typically a Type 5 or Type 6 chemical indicator, internal CIs are the most critical component of the quality control process because they monitor critical parameters of the sterilization process and ensure the instruments inside of the pack were properly exposed.

A “passing” response of a CI does not prove however that the item is sterile. It only indicates that, in the case of steam sterilization, steam was able to penetrate the packaging and reach the indicator for the specified amount of time at the specified temperature. If the interpretation of a CI suggests inadequate processing, the contents should not be used and facility procedures for sterilization failures should be followed.

Chemical Indicators are part of your overall sterility assurance program

It’s important to remember that chemical indicators are one of several sterility assurance tools, including biological indicators, used to assure that the processed instruments and medical devices are safe for patient use – but they are not the only indicator to review when deciding if a load is safe to release.

No one sterility assurance tool is better than another and each has its own purpose. When combined, they form a complete system to help protect against the use of a non-sterile device.

References

1 ANSI/AAMI ST79 Comprehensive guide to steam sterilization and sterility assurance in health care facilities