Sterilization temperature and pressure for sterilization with steam
Water vapor is suitable for sterilization as dry heat. Autoclave heating is also known as steam sterilization and is the standard procedure in most laboratories and hospitals (CSSDs)[1]. It is also used in the preservation of food in cans and glass packaging. The sterilized or filling material is sterilized as follows:
- 20 minutes at 121 °C at 1.1 bar – or
- 5 minutes at 134 °C at 2.1 bar – or
- For the destruction of prions 18 minutes at 134 °C at 2.1 bar
The air inside the autoclave is completely replaced by water vapor. This is the process of venting. Only after venting does the heating phase begin with saturated water vapor. After the load has reached the sterilization temperature, the countdown of the holding time begins. The actual duration of a sterilization process depends on various technical designs of the autoclaves, such as size, heating power, vacuum pumps and other technical factors. The autoclaves fall under the Pressure Equipment Directive and the Medical Devices Act respectively. Medical Device Operator Regulation and therefore require constant technical monitoring and safety control.
| Heat resistance | |||
|---|---|---|---|
| Resistance level | Organism/pathogens | Temperature (°C) | Time (min) |
| I | Pathogenic streptococci, listeria, polioviruses | 61,5 | 30 |
| II | most vegetative bacteria, yeasts, molds, all viruses except hepatitis-B | 80 | 30 |
| III | Hepatitis B viruses, most fungal spores | 100 | 5-30 |
| IV | Bacillus anthracis spores | 105 | 5 |
| V | Bacillus stearothermophilus spores | 121 | 15 |
| VI | Prions | 134 | 20 |