Microbes can cause ample diseases in humans and animals can also affect their health by spoiling the food. Therefore, it is beneficial to kill or inhibit their growth to minimize their harmful effects. A process that makes a medical device, instrument, or environment free from harmful microorganism (either by killing or inhibiting its growth)is referred to as decontamination. Decontamination can be achieved by processes like disinfection, sterilization or antisepsis. The process of killing or inhibiting the growth of microorganisms is called Disinfection and Sterilization. However, the way the two processes are conducted is quite different.

What is Sterilization?

A physical process that is followed to completely destroy all the forms of microorganisms present on any surface is called Sterilization. This process is followed mainly to preserve the substance for a longer time without decay. It is usually done by physical agents such as heat, radiation, filtration, etc.

What is Disinfection?

A process used to eliminate or inhibit the growth of bacteria and other pathogens causing infectious diseases in both humans and animals is called Disinfection. The chemicals used for this process are mainly chlorine, iodine, alcohol etc.

Methods Used in Disinfection and Sterilization

Some of the methods used in disinfection and sterilization are -

Antisepsis - It is a process in which microorganisms are destroyed in living tissue which limits the effects of infection.
Antiseptic - It is a chemical agent that is applied to living tissue to kill microbes.
Autoclave - It is a high pressure device used to allow the application of moist heat above the normal-atmosphere boiling point of water.
Biocide - They are the chemicals or substances that help to kill biological organisms.
Disinfectant - It is a germicide that kills virtually all recognized pathogenic microorganisms .
Decontamination - It is a method by which organisms are killed with no quantitative implication, generally by using the procedures for making items safe before disposal.

Factors affecting efficacy of Disinfection and Sterilization

The activities that are performed by the germicides against the microorganisms depends on a number of factors. Awareness of these factors will help us to beware of the germs. The factors affecting the efficacy of disinfection and sterilization are -

Number and location of microorganisms
Innate resistance of microorganisms
Concentration and potency of disinfectants
Physical and chemical factors
Organic and inorganic matters
Duration of exposure

Similarities Between Disinfection and Sterilization

Some common factors between Disinfection and sterilization are -

Both are used to decontaminate objects.
Both processes kill harmful microbes.
They destroy bacteria, protozoa, viruses and bacteria.

Differences between Disinfection and Sterilization

S.No.	Disinfection	Sterilization
1.	In this process, the number of harmful microbes is reduced to a minimal level.	In this process, the surface is made completely free.
2.	In this, only vegetative cells are killed and not the spores.	It kills both vegetative cells and spores.
3.	Chemical methods are used in disinfection	Physical methods are used in sterilization
4.	It only reduces the effect of microbes	It completely eradicates microbes
5.	Only required cleaning is done here.	Complete cleaning is done here.
6.	Phenol, alcohol, chlorine, iodine are some of the disinfecting agents.	Dry heat, filtration etc are some of the sterilization methods.

Conclusion

The main takeaway here is that the aim of disinfection and sterilization are different. The main purpose of a disinfectant is to kill or inactivate the harmful microorganisms. Sterilization, on the other hand, aims at killing all the microbes.

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