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