The sterilization working principle of the steam sterilization retort

   Steam sterilizers, or autoclaves, work by using saturated steam under pressure to eliminate all microorganisms. The core principle relies on moist heat to destroy microbes by coagulating and denaturing their essential proteins and enzymes .

   To achieve this, air is first removed from the chamber to allow steam to penetrate the load effectively . The chamber is then heated to high temperatures, typically between 121°C (250°F) and 135°C (275°F), by increasing pressure, often to about 15 pounds per square inch (psi) or higher . These conditions are maintained for a specific time (e.g., 4 to 30 minutes) to ensure complete sterilization . Finally, the steam is exhausted, and the load is dried to prevent recontamination . This method is highly effective, reliable, and widely used for processing heat- and moisture-stable items .