Sterilization in simple terms, refers to any process that effectively kills or eliminates transmissible agents (such as bacteria, viruses, spore forms etc.) from a surface, equipment or biological culture medium. Sterilization can be achieved through application of heat, chemicals, irradiation, or filtration. Of these, heat (steam) sterilization is proven to be the most effective.

No living thing can survive direct exposure to saturated steam at 250 F (120 C) longer than 15 minutes. Hence death / destruction of microbial life is necessary to achieve sterilization. Steam, for a specified time at required temperature, must penetrate every fiber and reach every surface of items to be sterilized. When steam enters the sterilizer chamber under pressure, it condenses upon contact with cold items. This condensation liberates heat, simultaneously heating and wetting all items in the load, thereby providing the two requisites: moisture and heat.

There is exact demand of temperature /pressure control, process accuracy and documentation to adhere sterilization truly. Now based on the application demand, Steam Sterilizers are categorized mainly into four categories :

1. GRAVITY DISPLACEMENT STEAM STERILIZERS

Empty glass ware , utensils , vessels instruments & lab scale articles are best sterilized in these sterilizers. The technique uses the method of gravity air removal to ensure uniform steam distribution & penetration.

2. VACUUM STEAM STERILIZER

Porous material like garments, fabrics, machine & changed parts, bulk powders etc. are best sterilized in these Sterilizers. The technique uses mechanical air removal thru Vacuum pump & ensures 100% air removal which results in better temperature uniformity in the chamber. There is better steam penetration in porous products & vacuum drying at the end ensures drying of the material which was sterilized.

3. RAPID COOLING STERILIZER

Terminal sterilization of ampoules, glass bottles & sterilization of heat labile products are best achieved in these sterilzers. Here compressed air is used to create over pressure which accelerate steam evacuation from chamber & also provides counter pressure to ensure container / bottle integrity. Atomized water spray cools the load within chamber.

4. VACUUM TEST STERILIZER

Glass ampoules with fine line crack occurred during manufacturing , filling gets busted when exposed to vacuum du to high differential over wall.