Difference Between in Biology

Difference Between Disinfection And Sterilization

Disinfection and Sterilization are types of sanitizing methods. Based on the purpose of purification, either disinfection or sterilization can opt. In this article, we will learn the Difference Between Disinfection and Sterilization.

In this decontamination, the main difference between sterilizing and disinfecting is that disinfection is the process of destroying or reducing harmful microorganisms from inorganic objects and surfaces, whereas sterilization is the process of killing all microorganisms.

Sterilization also eliminates the bacterium of various organisms present in liquids, on surfaces, in medication, or compounds such as biological culture media. Such an “ultimate” form of purification is required during critical surgeries, laboratory or hospital, or in an industrial environment. Compared to sterilization, disinfection can be used in everyday life.

Difference Between Disinfection And Sterilization

Difference Between Disinfection And Sterilization

Character Disinfection Sterilization
Definition In the Disinfection process, the number of harmful microbes is minimized to a negligible level. In the Sterilization process, the medium is made completely free from all microbes.
Method In this, the chemical methods are used for disinfection. In this, methods like a combination of heat, irradiation,  high pressure, chemical, and physical methods are used.
Effect It invades only vegetative cells and not the spores. It invades both vegetative cells and spores.
Microbes It only reduces the effect of microbes. It completely rids microbes from the surface
Wounds Wounds are disinfected. Wounds cannot be sterilized.
Cleanliness In Disinfection, there is adequate cleanliness. In Sterilization, there is extreme cleanliness.
Use It can be used in daily life. It is used primarily for medical and research purposes.
Techniques Phenol, alcohol, chlorine, iodine are some of the disinfecting agents. High temperatures, steam, radiation, filtration are some of the sterilization techniques.
Example Pasteurization, Disinfecting urinals, etc. Sterilization of instruments used during surgery by autoclaving.


Disinfection is the process of destroying unhygienic microorganisms. However, the process is not capable enough to stop the overgrowth of spores. Spores may be able to survive and result in contaminating the objects and surfaces.

Disinfectants are further classified into two types:

1) Broad-spectrum

Broad-spectrum disinfectant is the one that can be applied to a wide variety of pathogens. It is capable of eliminating a wide variety of pathogens.

2) Narrow spectrum

Narrow spectrum disinfectant is the one that can be applied to a tiny variety of pathogens and are easy to use, non-toxic, and comparatively affordable.

An ideal disinfectant should be capable of killing microorganisms within a stipulated time. It should possess a longer shelf life and capable of performing at any pH. It should have a broad spectrum of performance and not be toxic or allergic. It is active in the presence of organic matter.

Types of Disinfection

Air disinfectants

The droplets of disinfectants are sprinkled or vapor at a sufficient concentration in the air to reduce the number of practical infectious microorganisms. Chemicals used in this are propylene glycol and triethylene glycol.


These are very less effective on spores and fungus also. Chemicals used in this are formaldehyde and glutaraldehyde.

Oxidizing agents

This causes the microorganism to collapse. Chlorine and oxygen are strong oxidizing agents, so their compounds are used e.g. common household bleach. It is the most affordable home disinfectant used to clean toilets, swimming pools, drains, surfaces.


It is high-concentrated and is capable to successfully inactivate viruses such as HIV, hepatitis B, and hepatitis C. It usually consists of ethanol or isopropanol. Chemicals present are safe and affordable to use in a household environment. Special care should be taken around inflammable items.


The mouthwashes, Dettol are the best examples of the oldest known disinfectant. Chemicals used in this are Phenol, Chloroxylenol.


Sterilization is the process of removal, killing, eradication, elimination of all forms of life, and biological pathogens. Microorganisms like fungi, bacteria, viruses, spores, prions, located in places, like a surface, some fluid, and medicines are also eliminated by sterilization.

Sterilization is done by the use of certain solutions or sometimes by exposure to physical and chemical agents, by filtration. Physical methods consist of heat, radiation, and filtration.

Sterilization is important in the veterinary and the hospitals where it is very important to destroy highly resistant microorganisms. It is important to thoroughly sterilize the medical equipment, as they are used in invasive procedures with animals or humans. Pathogens like bacteria, viruses, and fungi are unable to survive after sterilization.

Types of Sterilization


Steam is used in machines like autoclaves heated to 121–134 °C. It is required to keep for a holding time of at least 15 minutes at 121 °C (250 °F) or 3 minutes at 134 °C (273 °F) for proper sterilization. Autoclave treatment invades all microorganisms like fungi, bacteria, viruses, and also bacterial spores.


Heating includes methods like under heating, flaming, incineration, boiling in water. These methods help to invade and kill microorganisms in objects like glass, metals. Boiling in water for 15 minutes destroys viruses and kills most of the bacteria.

Radiation sterilization

This method includes electron beams, X-rays, gamma rays, or subatomic particles for sterilizing throwaway medical equipment, such as syringes, needles, cannulas.

Sterile filtration

This method is used to sterilize the clear liquids that would be damaged by heat, irradiation, or chemical sterilization.

Chemical sterilization

In this, the chemicals like Ethylene oxide, ozone, Bleach, Phthalaldehyde, Hydrogen Peroxide, Dry sterilization process, Glutaraldehyde, and Formaldehyde, Peracetic acid, and Silver are used in varying degrees.

Products like biological materials, fiber optics, electronics, and plastics that can get damaged due to heat undergo chemical sterilization. Chemicals like Ethylene oxide gas and Ozone gas oxidize most organic matter.

Chemicals like bleach and Glutaraldehyde and formaldehyde solutions are highly concentrated in sterilization. Hence, these are used as a disinfectant. Dry sterilization is used to sterilize plastic bottle’s medical and pharmaceutical applications.

Methods of Sterilization and Disinfection

Disinfection is usually accomplished by using disinfecting chemicals. Some chemicals may be very effective and capable of destroying a wide variety of microorganisms, while others may be less capable. Disinfectants may be easy to use, less or nontoxic, or affordable.

Sterilization consists of three methods; physical, chemical, and Physiochemical. The physical method consists of heat, radiation, and filtration. Chemical methods include the use of liquid and gaseous chemicals. The combination of physical and chemical methods is known as the Physiochemical method.

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