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Types Of Disinfection And Factors To Consider When Buying A Disinfectant

Although the use of disinfectants may not be essential on a day-to-day basis, it is still an important step in the cleaning process. There are numerous things that one must consider before choosing a disinfectant and adopting a suitable type of disinfection process meant for your home and work space. 


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Bacteria, virus or fungal spores, there are numerous microorganisms that surround us at all times. While many of them are harmless, there are some that can result in the spread of infectious diseases. Before the pandemic, the use of disinfectants was restricted to health care settings, to bring down the risk of the spread of hospital acquired infections.

However, during the pandemic, more and more industries and facilities started the use of disinfectants and adopting different types of disinfection processes to ensure their surfaces were clean. Other than hospitals, various types of disinfection processes were adopted in schools, restaurants, hotels and offices to maintain a safe and hygienic environment.


Although the use of disinfectants may not be essential on a day-to-day basis, it is still an important step in the cleaning process. There are numerous things that one must consider before choosing a disinfectant and adopting a suitable type of disinfection process meant for your home and work space. 

What is Disinfection?

In brief, the term disinfection refers to the process of inactivating germs or killing bacteria and other pathogens. The primary objective of disinfection is to reduce the number of microbes on a given surface to such an extent that infection can be ruled out.

The main difference between sterilisation and disinfection lies in the number of germs that are left behind on a surface. When disinfection of a surface is completed, it is said that the number of pathogens on the surface are brought down to an order of magnitude of 105. This typically means that out of 10,000 germs, one may be left behind after any type of disinfection. On the other hand, sterilisation is known to achieve complete eradication of pathogens from a surface.


Factors to Consider Before the Use of a Disinfectant

A good disinfectant is one that kills bacteria on surfaces as efficiently as possible without causing any damage to the surface or injury to the person who is making use of the disinfectant. All good disinfectants must possess the following properties

●    Swift and complete germ reduction
●    Should be compatible with skin, mucous membrane, wounds, materials
●    Does not emanate very strong odours
●    Long shelf life
●    Environmentally friendly 
●    Should have low systemic toxicity (which refers to poisoning effect on the whole body)
●    As little loss of efficacy as possible due to protein or soaps

Every disinfectant will have a safety data sheet that will mention crucial details about the disinfectant. These typically include how to use it, what PPE to wear during the use of disinfectant, safety and storage information and more.

Along with the above mentioned properties, there are also some other factors to keep in mind before choosing a disinfectant and selecting a suitable type of disinfection method.

1.    Dwell Time

This is the time that it takes for a disinfectant to effectively kill pathogens. The disinfectant must remain on the surface for the specified amount of time.

2.    PPE (Personal Protective Equipment)


For certain disinfectant solutions meant for particular types of disinfection, PPE is required. You will need to read the safety data sheet to know which PPE you will need.

3.    Safety

While disinfectants are essential chemicals to kill bacteria and other pathogens, there are some that are safer than the others. To find the disinfectant solutions that are the safest, look for a low toxicity rating from EPA.

4.    Surface and Application

You need to be careful with the kind of disinfectant solutions you use on certain surfaces. While a particular disinfectant may work well on surfaces like restaurant tables, the same may not be appropriate for use on soft surfaces like couches.


5.    Ease of Use

Many of the above mentioned points also collectively contribute to a disinfectant solution’s ease of use. For example, if your disinfectant has a high dwell time and needs the use of PPE, more time will be spent on the process of disinfection. Or worse, you may skip some steps on the instruction manual as the use of disinfectant is complex and time consuming.

Types of disinfection and How a Disinfectant Works

The effect of a disinfectant depends on different chemical and physical processes to kill bacteria and other pathogens or to stop them from multiplying. The main types of disinfection include: -


●    Protein Denaturation: - In this type of disinfection the protein building blocks of pathogens are attacked, for example the protein envelope of viruses.

    Oxidation: - Microorganisms are inactivated or killed by the reaction with oxygen in this type of disinfection.

    Chemical Reaction with the Nucleic Acids: - This type of disinfection alters or destroys the genetic material of pathogens so that they cannot multiply any more.

    Enzyme Inhibition: - This type of disinfection inhibits the essential metabolic processes of pathogens.

Additionally, agents that reduce surface tension are often included in the disinfectant solution formula(for e.g., surfactants which are found in soap). This supports the process of disinfection.


Non-Chemical Methods of Disinfection

A disinfectant is usually defined as a liquid meant for chemical disinfection that utilises any of the above-mentioned types of disinfection. Additionally, there are also some non-chemical methods of disinfection that kill bacteria and other pathogens by physical means. These non-chemical methods of disinfection are: -

1.    Heating: - This method of disinfection plays an essential role in the preservation of milk. However disinfecting surfaces with heat also play an important role in sterilisation. For example: - laboratory autoclaves.

2.    Irradiation: - Another method of disinfection that is achieved by use of UV radiation, gamma radiation or ionizing radiation.


3.    Mechanical Methods: - Pathogens can also be eliminated by mechanical destruction like cell disruption in this method of disinfection.

Classification of Disinfectants According to Efficacy

It is critical to remember that not every disinfectant is effective against all microorganisms. Depending on the ingredients used, each disinfectant has an effect only on some microorganisms and there will be some that are not affected by it at all. Depending on their spectrum of activity, disinfectants are further classified into 4 types:

1.    Bactericidal

Disinfectants that kill bacteria and act against bacteria are called bactericidal. They involve chemical disinfection with chemicals like alcohols, phenols and chlorine.


2.    Virucidal

If your aim is to protect yourself from viral diseases then it is essential to use a disinfectant labelled as Virucidal. But not all viruses are the same. Hence, some active ingredients would affect only some enveloped viruses. Based on their activity they can be categorised into 3 kinds: -

●    Limited Virucidal: - This disinfectant solution’s use is seen against enveloped viruses like herpes, measles and coronaviruses.
●    Limited Virucidal PLUS: - Effective against enveloped viruses and adeno-, Noro- and rotaviruses.
●    Virucidal: - This is useful against enveloped and non- enveloped viruses, such as hepatitis B or human papilloma viruses.


3.    Fungicide

Fungicide disinfectant solutions are useful against fungal cultures and not fungal spores.

4.    Sporicidal

Disinfectants with active ingredients that make fungal or bacterial spores lose their ability to germinate are known as sporicides. Only selected disinfectants are classified as sporicidal and they include reactive oxidants like peracetic acid, chlorine, sodium hypochlorite, chlorine, hydrogen peroxide that are used in chemical disinfection.

Thankfully there are many disinfectants that work against a broad spectrum of pathogens at the same time. For example, chemical disinfection with alcohol will help take care of bacteria, enveloped viruses and fungi.

Classification of Disinfectants According to Use


Disinfectants are also classified according to their use. This is because different disinfectants are used depending on whether they are meant to disinfect hands, floor or for chemical disinfection in hospitals. According to use, the different methods of disinfection are: -

1.    Hand Disinfection

Hand disinfectants are meant to sanitize hands or for hand cleaning when water and soap are unavailable. They need to be well tolerated and are often enriched with caring or relubricating substances. Active ingredient is often alcohol in hand disinfectants

2.    Skin Disinfection

During operations, infections or other invasive procedures the skin surface needs to be disinfected to prevent germs from being carried into the body. Just like with hand disinfectants, alcohol based solutions are a type of disinfectant used in hospitals for spraying or applied with swabs on the skin.


3.    Surface Disinfection

All contaminated surfaces including floors, operating theatres, home sanitization, deep kitchen cleaning , couches or toilets can be cleaned with surface disinfectants. In this type of disinfection, wipe disinfection is preferred to spray disinfection. This is because there are chances that small droplets of disinfectant can get into the lungs while spraying.

Also check the compatibility of the disinfectant with the material to be cleaned. For example, alcohol-based disinfectants can stain floors.

4.    Instrument Disinfection

These disinfectants are utilised in the reprocessing of surgical and medical instruments. This type of disinfection is either done with heat or by using a combination of heat and chemicals.


5.    Laundry Disinfection

In this type of disinfection, chemical laundry disinfectants are used in various industries like the medical sector, hotels, railways etc. to ensure that textiles are hygienically cleaned even at low temperatures. Chlorines, peracids, aldehydes are the active ingredients found in laundry disinfectants.

6.    Water Disinfection

Some of the approved chemical disinfectants for water include sodium and calcium hypochlorite, chlorine dioxide, chlorine and ozone. Some other methods of disinfection are boiling of water or UV irradiation.

Chemical Methods of Disinfection

The ingredients in the disinfectant meant for chemical method of disinfection depend on what the purpose it serves. Based on the type of disinfection, various disinfecting agents are combined as well as supplemented with other ingredients to protect the skin from drying out and making the product effective and safe.


Some of the common active ingredients used for chemical methods of disinfection are:-

1.    Alcohol: - Alcohol is a common active ingredient in disinfectants as it kills bacteria and inactivates viruses at high rates. However, it is ineffective against bacterial spores. Alcohols may require a greater dwell time than other disinfectants. It is a popular disinfectant used in hospitals.

2.    Chlorine and Chlorine compounds: - They are useful in fighting a wide range of microorganisms including bacteria and viruses. It is inexpensive and acts quickly hence is used to disinfect water for decades. Household bleach is a category of chlorine. However, chlorine compounds can be toxic in large doses. Proper ventilation and appropriate PPE are required while using them.


3.    Formaldehyde: Even at low levels this chemical disinfectant leaves behind a strong odour and produces irritating fumes. It’s extremely effective but is not used often due to its smell and health risks.

4.    Glutaraldehyde : This chemical is a disinfectant used in hospitals and dental clinics to disinfect heat sensitive equipment. However, it’s been found to be too deadly and expensive to use even when the disinfectant is diluted.

5.    Hydrogen Peroxide: Hydrogen peroxide-based products are known to be safe and environmentally friendly options. It breaks apart pathogens without leaving behind any odour.

6.    Iodophors: Iodophors are not used very often they have a strong odour. However, they can penetrate and disrupt the cell walls of pathogens easily. They also can stain surfaces. Iodophors are a common disinfectant used in hospitals as an antiseptic.


7.    OPA (Ortho-phthalaldehyde): OPA is a high-level disinfectant that is similar to glutaraldehyde. Fortunately, it does not irritate the skin, eyes or have a strong odour. Research has shown that OPA based disinfectants last longer on surfaces.

8.    Peracetic Acid: Peracetic acid is unstable when diluted but does not leave behind any residue. They are used primarily to disinfect medical equipment in hospitals.

9.    Peracetic Acid and Hydrogen Peroxide: The combination of peracetic acid and hydrogen peroxide has been found to be extremely effective against almost all microorganisms except bacterial spores that too within just 20 minutes.

10.    Phenolics: Phenol based products are popular disinfectants used in hospitals for decades now. However, they have not been found effective in inactivating viruses. Many phenolics are used on surfaces like bedside tables, bedrails etc.
11.  Quaternary Ammonium Compounds: Quaternary Ammonium Compounds are used as active ingredients in disinfectants as they act quickly against microorganisms and are less expensive. They are also referred to as Quats. Products with Quaternary Ammonium Compounds are used on a variety of surfaces including furniture, floors and even medical equipment.


Instructions on Application Technique of Different Types of Disinfectants

To effectively prevent the spread of diseases along with selecting a suitable disinfectant one must also know how to correctly apply the disinfectant. Below are the various steps to keep in mind while disinfecting hands and other surfaces.

Hand Disinfection

It is crucial to follow the manufacturer’s instructions in this type of disinfection . They include

●    The recommended amount per disinfection.
●    The prescribed exposure times
●    The right concentration of the disinfectant solution.

The general recommended time for exposure for a hand disinfectant is about 30 seconds. If one does not follow this accurately the disinfectant may not work thoroughly. The microorganisms will remain on the hand and increase the risk of infection.


The correct rub in techniques must be followed for hand disinfection a it will ensure that the disinfectant reaches all the surfaces of the hand. Hands should always be dry before disinfection as wet hands will dilute the disinfectant and render it ineffective.

Surface Disinfection

In this type of disinfection, observe the exposure time and recommended concentration according to the manufacturer’s instructions. For wipe disinfection the surface should be sufficiently wet and not just moist.

It is best to wear gloves while handling surface disinfectants as they are tolerated well by the skin.

Ensure you wear disposable gloves and do not immerse used clothes in the disinfectant solution repeatedly for hygiene purposes.


You can trust Dettol disinfectant sanitizer spray if you are looking for a great disinfectant spray in India. It is easy to carry and works on both hard and soft surfaces and provides germ protection and kills 99.9% of bacteria and viruses.


1.    When do I need to use a disinfectant?

In everyday life using a disinfectant may not be necessary. However, if anyone is suffering from infectious diseases in the household like covid, diarrhoea or while dealing with immunocompromised individuals, disinfection is beneficial.

2.    When is cleaning with soap and water enough?

As long as your home is free of any infectious diseases and there ae no specially susceptible people living with you, using soap and water to clean hands is enough. Hand washing is very effective in preventing the spread of infectious diseases. It is imperative to scrub hands for at least 20 to 30 seconds and clean all sides.


3.     How long does a disinfectant have to work?

Most disinfectants would require at least 30 seconds of exposure time to be effective. Butt he exposure time can vary depending on the type of disinfectant and active ingredient. It is best to follow the instructions on the label.

4.    Which Substances have a disinfecting effect?

Disinfecting substances include chemicals like alcohols, chlorine, hydrogen peroxide, iodophors, aldehydes etc. Bases on the intended use some chemicals are more suitable than the others.

5.    Are expired disinfectants effective?

Expired disinfectants are not reliable hence they should be disposed off once they reach cross their expiry date.


6.     Are disinfectants harmful to children? Can children apply disinfectants?

Children should stay away from disinfectants. They should not apply them and this includes even disinfectant wipes. All disinfectant label’s carry the warning “ Keep out of reach of children “as they can be potentially harm the health of a child.

7.    How do I choose the right disinfectant?

In most cases a given disinfectant is intended for a specific purpose and needs to be used in a specific way. Hence, users should read the label of the product properly to ensure they are selecting the right disinfectant and applying it efficiently.


8.    In India, which disinfectant spray is the best?

Dettol disinfectant sanitizer spray is a trusted and highly rated product in India. It kills 99.9% of bacteria and viruses and provides germ protection and is great for everyday use.