Disinfect Vs Sterilize: Differences Based on Definition, Method, Types, Cleanliness, Processing Time, Application

Disinfection and sterilization are two separate methods for killing or eliminating microorganisms from any object or surface. There are some noted differences between the two; and we will point out some of the differences between disinfect and sterilize in this current article.

Disinfect Vs Sterilize. Differences Based on their Definition

Disinfect. To disinfect, means to eliminate or remove the harmful microbes (excluding their spores) from the objects or surfaces, and inactivate the viruses.
Sterilize. To sterilize means, killing or destroying all microorganisms, maybe harmful or may not, along with their spores, which are present on objects or surfaces.

Disinfect Vs Sterilize. Differences Based on the Methods

Disinfect. Disinfect is something that is generally carried out with the help of some chemicals known as the disinfectants. Some disinfectants might be more effective than others and have a wide spectrum. These disinfectants might be quite easy to use, inexpensive and can be non-toxic.

Sterilize. Sterilize is another method to eliminate the microbes and it can be done by any three methods, i.e. physical method, chemical method or by physiochemical method. Heat, filtration and radiation are included in the physical method of sterilization; chemical methods of sterilization include the use of liquid and gaseous chemicals; while the physiochemical method of sterilization is actually a combination of physical as well as chemical method of the sterilization.

Disinfect Vs Sterilize. Differences Based on the Types

Below are some of the different types of disinfectants and ways of sterilization we are going to know about.

Types of Disinfectants.

  • Air Disinfectants. Air Disinfectants are dispersed either as vapor or as an aerosol at a sufficient concentration in air so as to reduce the number of viable infectious microbes. Propylene glycol and triethylene glycol are the chemicals used as Air Disinfectants.
  • Alcohols. High concentrations of alcohol can be used to inactivate the viruses, such as Hepatitis B, HIV, Hepatitis C in an effective manner. Chemicals present are usually ethanol or else isopropanol. These alcohol types are safe, as well as inexpensive to use in the house; however, care must be taken properly when using alcohol around inflammable items.
  • Oxidizing Agents. These agents result in the collapsing of the microorganisms. Some strong oxidizers are chlorine and oxygen; and thus their compounds are generally used for common household bleach. This is in fact the most cost-effective way of disinfectant that is used for cleaning drains, toilets, swimming pool and surfaces.
  • Aldehydes. Aldehydes are specifically effective on disinfecting fungus and also on spores. Chemicals include formaldehyde and glutaraldehyde.
  • Phenolics. One of the oldest known type of disinfectants are phenolics. Example. Dettol and mouthwashes.
  • Quaternary Ammonium Compounds or Quats. These types of disinfectants are quite effective, but low level disinfectants. Chemicals-benzalkonium chloride.
  • High-Intensity Shortwave UV Light. This is also used for disinfecting smooth and opaque materials.
  • Common Sodium Bicarbonate. Common sodium bicarbonate or NaHCO3 is also used as a common disinfectant because of its disinfectant properties.

Types of Sterilization.

  • Steam Sterilization. Steam sterilization is a type of sterilization that is done with the help of machines called the Autoclaves. These autoclaves make use of steam that is heated to 121 degrees to 134 degrees C. In order to attain sterility, it is required to have a holding time of 15 minutes at 121 degree C or at least 3 minutes at a temperature of 134 degree C. With the autoclave treatment, the bacteria, fungi, viruses, bacteria and also bacterial spores get inactivated. It must be mentioned that pressure cooking food items is also a type of steam sterilization, though it is not that very thorough of a sterilization.
  • Heating. Boiling in water, tyndallization, dry heat, under heating flaming, are all the methods of heating that inactivates and also kill microbes present in objects, such as glass and metals. Boiling in water at least for 15 minutes sterilizes or inactivates different viruses and also kills most of the vegetative bacteria. However, it must be noted that this boiling has no effect on the bacterial spores.
  • Tyndallization is actually the boiling for about 20 minutes and then after cooling, again boiling and once again cooling for 3 times. This method of heating is comparatively more effective in sterilizing bacterial spores than mere boiling.
  • Dry heat method of heating can be used on powders and other things that can bear extreme high heat.
  • Sterilization Using Chemicals. Sterilization by help of chemicals is known to be quite effective in sterilizing several products, plastic bottles and pharmaceutical applications. Chemicals such as Ozone, Ethylene oxide, Glutaraldehyde and Formaldehyde, Bleach, Hydrogen Peroxide, Phthalaldehyde, Peracetic acid and silver are used in varying degrees for sterilization. Dry sterilization process along with chemicals is also useful, especially in sterilizing pharmaceutical and medical applications and plastic bottles.
  • Radiation Sterilization. Electron beams, gamma rays, x-rays, or subatomic particles are used to sterilize disposable medical equipments, like needles syringes, IV sets, cannuals and biological safety cabinets, between their uses.
  • Sterile Filtration. Typically clear liquids that would get damaged by heat, chemical or radiation sterilization can be sterilized by a kind of mechanical filtration. Sterile filtration is another type of sterilization. Filtration is done via pores that are much smaller in size than the organism and this type of sterilization must be done very slowly.

Disinfect Vs Sterilize. Differences Based On Their Application

Disinfection. There are differences between disinfect and sterilize, based on their application. Disinfection is mostly used for decontaminating surface and air.
Sterilization. However, sterilization is basically used for surgical instruments, food and medicines.

Disinfect Vs Sterilize. Differences Based On Status Of Cleanliness

You get adequate amount of cleanliness when you disinfect an object or any surface. However, you get absolute or rather, extreme cleanliness when you sterilize any object or any surface.

Disinfect Vs Sterilize. Differences Based On Their Processing Time

Disinfection. In case of disinfection, the processing time basically depends on the process that has been adopted. For example, the objects used in the heat sensitive, semi-critical medical patient care can be pasteurized for about 50 minutes.

Sterilization. In case of sterilization too, the processing time primarily depends on the process and the temperature used to sterilize. For instance, all the heat tolerant critical equipments are sterilized using steam for around 40 minutes and by using dry heat for about 1-6 hours; both depends on the temperatures used.


So, from the above articles, we are now clear about some of the noted differences between disinfect and sterilize. It is always essential for you to choose the best possible method to eradicate or eliminate the unwanted microorganisms from the surface or objects, food or medicines and to keep them clean before using them.

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:February 12, 2019

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