Skip Navigation Links.

Sterilization and Decontamination, Methods

Sterilization is the process of eliminating or destroying all forms of microorganisms, including bacteria, viruses, fungi, and spores, from a surface, substance, or environment. The goal of sterilization is to achieve a level of microbial inactivation that ensures the absence of viable microorganisms and prevents the transmission of infectious agents.

The choice of sterilization method depends on factors such as the type of material or object to be sterilized, its intended use, and the level of microbial reduction required.

Common methods of sterilization include:

  1. Heat Sterilization: This method uses heat to kill or inactivate microorganisms. It can be achieved through moist heat (autoclaving) or dry heat sterilization. Autoclaving involves subjecting the items to high-pressure steam at a specific temperature and time to achieve sterilization. Dry heat sterilization uses hot air or flames to achieve the desired effect.
  2. Chemical Sterilization: Certain chemicals, such as ethylene oxide (EO), hydrogen peroxide, and formaldehyde, can be used to sterilize heat-sensitive materials. Chemical sterilization requires specialized equipment and proper handling to ensure effective sterilization and safe use of the sterilizing agent.
  3. Radiation Sterilization: Ionizing radiation, such as gamma radiation or electron beams, can be used to sterilize materials. It damages the genetic material of microorganisms, rendering them unable to reproduce. Radiation sterilization is commonly used for disposable medical products, pharmaceuticals, and some food products.
  4. Filtration: Sterilizing filters with pore sizes smaller than the microorganisms can be used to physically remove or trap them. Filtration is commonly used for heat-sensitive liquids, gases, or air.

It is important to note that sterilization is different from decontamination, which generally refers to the reduction of microbial contamination rather than complete elimination.

Sterilization vs. Decontamination

Sterilization and decontamination are two related processes, but they have distinct differences in terms of their objectives and the level of microbial reduction achieved.

The goal of sterilization is to achieve a state of absolute sterility, where there are no viable microorganisms present that could potentially cause infection or contamination. Sterilization methods aim to achieve a high level of microbial inactivation, typically a reduction of at least 10^-6 (a 6-log reduction) in microbial population.

Decontamination, on the other hand, refers to the reduction or removal of contaminants, including microorganisms, from a surface or object to a level that is considered safe or acceptable for a specific purpose (usually 10^-3 (a 3-log reduction). Decontamination may not necessarily achieve complete elimination of all microorganisms, but it aims to significantly reduce their presence and potential risks. The level of decontamination required depends on the specific application and the desired level of risk reduction.