Type of autoclave and its definition

 

Autoclave Definition

An autoclave is a machine that provides a physical method of sterilization by killing bacteria, viruses, and even spores present in the material put inside of the vessel using steam under pressure. Autoclave sterilizes the materials by heating them up to a particular temperature for a specific period of time. The autoclave is also called a steam sterilizer that is commonly used in healthcare facilities and industries for various purposes. The autoclave is considered a more effective method of sterilization as it is based on moist heat sterilization.
The autoclaving process takes advantage of the phenomenon that the boiling point of water (or steam) increases when it is under high pressure. It is performed in a machine known as the Autoclave where high pressure is applied with a recommended temperature of 250°F (121°C) for 15-20 minutes to sterilize the equipment.

Autoclave classes

1. Class N autoclave

Class N autoclave is the lowest class device. According to European standard EN 13060, since 2004 it can be used only as an auxiliary unit. Sterilizer of this class does not have a vacuum pump (which is present in higher class autoclaves), so only instruments with a solid structure can be sterilized within such device. It is also not possible to sterilize hollow or porous cartridges or sterilize items in packages. Class N sterilizers also do not have an effective drying option, unlike more advanced autoclaves.

2. Class S autoclave

Class S autoclave is an intermediate class between N and B. Within such device we can sterilize more complex instruments, B type batches, except for instruments of capillary construction (A type batches). Class S allows the sterilization of single-packed, multilayer packed and more massive instruments, which cannot be sterilized in class N autoclaves. Autoclaves of this class have a vacuum pump, which makes it possible to completely remove the air from the chamber before starting the sterilization process. However, only a single-stage pre-vacuum is used here; it is less effective than the vacuum used in class B autoclaves.

3. Class B autoclave

Class B autoclaves are the most advanced steam sterilizers. These are certified MEDICAL DEVICES USED IN BEAUTY PARLOURS, tattoo studios, private dental parlours, even in hospitals and large clinics. They also meet all the sanitary-epidemiological requirements. They can sterilize all types of batches, even the most complex ones. Class B autoclave, thanks to fractionated pre-vacuum, completely removes air from the chamber. It is the most effective modern technique of  sterilization of all types of tools.

Positive pressure displacement type (B-type)

• In this type of autoclave, the steam is generated in a separate steam generator which is then passed into the autoclave.
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• This autoclave is faster as the steam can be generated within seconds.

Negative pressure displacement type (S-type)

• This is another type of autoclave that contains both the steam generator as well as a vacuum generator.
• Here, the vacuum generator pulls out all the air from inside the autoclave while the steam generator creates steam.
• The steam is then passed into the autoclave.
• This is the most recommended type of autoclave as it is very accurate and achieves a high sterility assurance level.
• This is also the most expensive type of autoclave.

• Gravity displacement type autoclave

  • This is the common type of autoclave used in laboratories.
  • In this type of autoclave, the steam is created inside the chamber via the heating unit, which then moves around the chamber for sterilization.
  • This type of autoclave is comparatively cheaper than other types.

  Positive pressure displacement type (B-type)

  • In this type of autoclave, the steam is generated in a separate steam generator which is then passed into the autoclave.
  • This autoclave is faster as the steam can be generated within seconds.
  • This type of autoclave is an improvement over the gravity displacement type.