Decontamination

In the broad sense of emergency management and military operations, decontamination is the process of removing all hazardous material such that it does not present a threat. Such materials include hazardous biological organisms (including biological weapons, toxic chemicals (including chemical weapons, fire hazards, scattered explosives, radioactive materials (including radiological weapons), etc. Decontamination is concerned with the immediate "render-safe" situation, a term of art from explosive ordnance disposal; it is not necessarily concerned with the removal or long-term storage of materials that remain hazardous.

Biological

In biology, decontamination is the removal of microbial life forms. An item is said to be sterilized when all microbial life forms have been removed.

The purpose of sterilization is to destroy every microbial life form on inanimate items, such as surgical instruments. It is done using means that are deadly to all known microbes, such as chemicals, radiation and heat. Sterilization is not done on humans because the agents that are deadly to microbes are also deadly to humans. Some microbes that live on humans are useful and protect against other harmful microbes.

Heat

Heat may be used either to reduce a microbial populations to safe levels, as in pasteurization, or to kill all forms, as in sterilization.

Pasteurization

The purpose of pasteurization is to destroy common heat sensitive pathogens without reduction in nutrient value or change in flavor. Food is being heated to 60-70 degrees celsius for 30min to 15sec. The higher the temperature, the less time it takes to kill the pathogens.

Sterilization

Current standards for complete sterilization require moist heat above the temperature of boiling water, which is provided by steam in an autoclave. The general medical standard is 121 degrees Celsius for 20 minutes or more (previously 15).

Effective sterilization for food products can take place at less stringent levels. For preserving acid foods, canning or bottling them in sterile containers, which are then immersed in boiling water for a time appropriate to the amount and type of food.

For more alkaline foods, pressure canning in a home-grade autoclave is adequate. Since the food should be scrupulously clean, the microbial load is less than would be present in medical waste.

Chemical

Chemical - Bactericides are a group of chemicals that kills all bacterias, except for those in endospore stage. This group of chemicals focus on bacteria, so they may or may not be harmful to other kinds of microbes.

Fungicides are a group of chemicals made to destroy fungal spores, hyphae, and yeast.

Virucides are a group of chemicals made to inactivate viruses, especially on living tissue, where their metabolism takes place.

Sporicides are a group of chemicals made to destroy bacterial endospores. Bacteria in their endospore stage are the hardened Spartans of the microbial world. The chemicals that kill endospores will surely kill all other microbes. That's why sporicides can also be regarded as sterilants.

Radiation

Gamma radiation is used as a sterilant by breaking chromosomes. An advantage of gamma radiation is that it can be applied in a factory as a part of an automated production line. The ratio of number of items sterilized above cost of purchasing and handling of the radioactive sterilant is larger than the ratio of other sterilants. However, radioactive material isn't cheap and is very hazardous to handle. Are not to be used on small quantities and on large