Chemical indicators; simply indicates conditions of the sterilization that the package is exposed to where it is placed.
However chemical indicators are designed to work in a certain temperature-time interval, and they never work correctly outside these intervals.
For example, if the temperature is above the recommended range, the indicator will change its color earlier than expected due to areal overheating in the package.
However, microbial death, which will occur at high temperature without sufficient moisture, will be much slower. The value of the information that chemical indicators will provide depends on the class, number and position of the indicator in the sterilizer. These indicators should be placed in areas that are detected during process validation and can represent the entire sterilizer.
If a chemical indicator does not perform the necessary color change after the cycle, it should never be interpreted as the indicator does not work properly. It must be evaluated that an error may have occurred in the sterilization process and the process should be reviewed in terms of the following possible problems:
* Does the sterilizer have a malfunction that prevents it from reaching set values?
* Is there a change in packaging material?
* Is there a change in the amount of material in the package?
* Was the routine maintenance and calibration of the sterilizer performed properly and on time?
* Was the correct sterilization program used?
* Was the chemical indicator used according to the manufacturer's recommendation?
* Is there an external problem that may affect the sterilizer cycle? (For example, vapor pressure, current velocity, and non-condensed gases contained in it.)
Sterilization Disinfection Guide 2015