Do you know the different types of disinfection?

“Cleanliness is next to Godliness” is a saying we have heard multiple times. It is undoubtedly true as unclean places are a hub for pathogens to multiply. Recently, the emphasis on clean & hygienic surroundings has got more interesting. Looking at one of the few positives of the COVID-19 pandemic, people have become keener to learn about cleaning, disinfection, and sanitization. In this article, you can expect to learn more about disinfection and its different types & methods. 

What is disinfection? Why is it important?

When the surroundings are contaminated, then pathogens multiply. There is a high risk of disease transmission due to it. What if there is a way to keep the surroundings hygienic & uncontaminated? Disinfection is one such method of killing, destroying, or deactivating pathogens. It helps in curbing their growth & multiplication. 

Note: The difference between disinfection & sterilization is that in sterilization, all the microbes, irrespective of being harmful or harmless, are eliminated. Due to this reason, for hygienic & uncontaminated surroundings, disinfection is preferred. 

It has been proven by many researchers that disinfection is one of the most effective methods of elimination of pathogens. Even during the COVID-19, disinfection proved to be a boon. For effective results, however, it is vital to know the correct method of disinfection that must be employed to eliminate pesky micro-organisms. 

Types of disinfection

When broadly classified, there are only two types of disinfection based on the disinfection methods employed. These two methods of disinfection are physical & chemical. Foremost, we will discuss Chemical disinfection.

Chemical disinfection

In this disinfection method, chemical agents (also known as chemical disinfectants) are used to disinfect the surroundings. One of the most common & well-known disinfectants is bleach. Other chemical disinfectants include chlorine, ozone, hydrogen peroxide, iodine, phenol, ethanol, rubbing alcohol, acids, alkalis, formaldehyde, quaternary ammonium salts, etc. Let’s discuss a few chemical disinfectants. 

Note: In many cases, based on the requirements, one can use more than one disinfectant for disinfection purposes. One can check out our blog on disinfectants to know more.

Classification of chemical disinfectants

They are classified based on the source. When the disinfectants are extracted from natural sources, they are called natural disinfectants. These disinfectants are considered to be environment-friendly. They usually don’t have any side effects. Artificially manufactured disinfectants are special chemicals manufactured in labs & factories for disinfection. Usually, these disinfectants may have better effectiveness & efficiency in eliminating pathogens. Interested ones can check out our blog on natural disinfectants.

Ethyl alcohol & rubbing alcohol

Only these two alcohols have disinfection properties. They have good disinfectant properties against bacterial pathogens but fail to eliminate viruses & endospores, hence they are used along with other disinfectants. The ideal concentration for the best effectiveness of the alcohol disinfectants is 70% (and the rest 30% includes water & other additives). 

Formaldehyde

Formaldehyde is considered to be a disinfectant as well as a sterilant. As it is considered to be carcinogenic, it is to be handled carefully. It is not used for domestic disinfection. Formaldehyde disinfects by inactivating the pathogens by alkylating the proteins.

Peracetic Acid and Hydrogen Peroxide

The combination of these two disinfectants is 0.23% peracetic acid & 7.35% hydrogen peroxide. It has been scientifically proved that this combination is capable of eliminating a wide range of pathogens (except the endospores). Moreover, it takes around 20 minutes to eliminate pathogens. They are widely used for the disinfection of medical equipment.

Phenol & phenolic compounds

Phenol has been historically used for disinfection. With strong scientific pieces of evidence, phenol has been replaced by phenolic compounds, which are much safer & effective disinfectants.

Quaternary Ammonium Compounds

In the current scenario, QACs are widely used as disinfectants. They are considered a strong disinfectant with the ability to eliminate a wide variety of pathogens. QACs eliminate pathogens in several ways including denaturation of cell proteins, inactivation of vital enzymes, affecting the function of the cell membrane, etc. QACs are EPA-registered disinfectants used for the disinfection of floors, walls, tools, and equipment. They are used for domestic as well as commercial disinfection.

Chlorination 

The disinfection involving chlorine or chlorine compounds is called chlorination. This disinfection method is widely used for large-scale disinfection of water.

Chlorine Gas

A gas that was once used as a weapon in the World War has disinfectant properties. The greenish-yellow gas is toxic & lethal even at a lesser concentration. Hence, it is not used for household disinfection, instead is used for disinfection of water. It is considered to be one of the best water disinfectants as it can remove almost every pathogen present in it. The cost for disinfection of water with chlorine is relatively inexpensive, with an elimination of a  wide range of pathogens. 

Bleach (Active ingredient - Sodium hypochlorite) 

It is one of the most used disinfectants. Bleach has sodium hypochlorite (NaOCl) as its active ingredient. It doesn’t have any disadvantages like chlorine (such as toxicity, difficulty in handling, etc). Hence it is widely used even for domestic disinfection. Bleach solution contains chlorine (called available), which gives it the disinfectant property. This available chlorine varies in concentration depending upon the manufacturing & storage conditions. Generally, the concentration can be anywhere between 5% to 15%.

Calcium hypochlorite

This disinfectant is used for water disinfection. It is a solid disinfectant used as a replacement for chlorine or bleach owing to its safe handling. It has around 60% to 70% available chlorine. 

Ozone

An unstable allotrope of oxygen that consists of three oxygen molecules has disinfectant properties. It is a strong oxidizing agent, which decomposes rapidly. As it is highly unstable, ozone is not used for domestic disinfection. Though it has the advantage that it requires very less time to eliminate the pathogens.

Physical disinfection

The most commonly used physical disinfectant is UVC rays. UVC rays act as an ideal disinfectant with effectiveness in air, water, and solid surfaces. For more information, check out disinfection by UVC rays. Apart from UVC rays, electron beam rays, gamma rays, and even intense sunlight & heat are used for disinfection purposes. 

FAQ: Is there any other type of classification of disinfection?

Disinfection can also be classified based on the mode of application of the disinfectant. This includes spraying, wipes, mopping, electrostatic spraying, sprinkling, fogging, fumigation, etc. For domestic household purposes, spraying & mopping are widely used. But, we recommend the use of small fogger machines for quick effective results. You can also consider checking out some other top FAQs on disinfectants. 

Note: When considering domestic disinfection, disinfectants & mode of application are chosen based on the ease of handling & safety. 

Conclusion

Disinfection is a go-to method for the elimination of pathogens, both for household & large-scale applications. Disinfection is classified based on disinfectant sources & mode of application. The article has covered both the classifications and various types of disinfection.