CRCST Progress Practice Test 2025 – Complete Exam Prep Resource

A common indicator of sterilization failure is the unchanged presence of biological indicators. Biological indicators contain viable spores of highly resistant microorganisms, and their presence indicates that the sterilization process did not kill these spores. If these indicators show no change after the sterilization cycle, it suggests that the conditions necessary for effective sterilization were not achieved, signaling a failure in the process.

While a change in color of a chemical indicator (the first choice) can suggest that certain conditions for sterilization were met, it does not definitively indicate that the process was successful at eliminating all microorganisms. On the other hand, superheated steam production is not directly associated with sterilization failure; rather, it is an operational condition that needs to be properly managed during the process. Expiration of sterile packs refers to the loss of sterility over time, which is not a direct indicator of the effectiveness of a sterilization cycle itself. Thus, the unchanged presence of biological indicators provides a more reliable measure of sterilization failure.