This document discusses different types of controls used to verify the effectiveness of sterilization processes. There are three main types of controls: physical, chemical, and biological. Physical controls monitor temperature, humidity, and pressure parameters. Chemical controls use indicators to detect anomalies, but do not guarantee sterility. Biological controls, using spores of resistant microorganisms, are needed to confirm a sterility assurance level of 10-6, meaning less than 1 contaminated item per million sterilized. Common biological indicators include spore-containing strips or ampoules that are processed and incubated to check for microbial growth.