There are many types of disinfectants. Have you chosen the right one?

With the progress of science and technology, human society has achieved unprecedented great development. Despite this, our life, health and safety still face various threats from nature, one of which is highly infectious diseases. From plague to cholera, Ebola hemorrhagic fever, to atypical pneumonia and even new coronavirus pneumonia, we continue to feel that we are so vulnerable to bacteria and viruses. How can we make ourselves stronger and build a barrier against bacteria and viruses? In addition to exploring the pathogenic mechanisms of bacteria and viruses, taking preventive and therapeutic measures such as vaccination and drug development, we should also pay attention to personal hygiene and develop good hygiene habits including frequent hand washing, more ventilation, wearing masks, paying attention to coughing etiquette, and maintaining a safe social distance. Of course, paying attention to disinfection and sterilization is also an indispensable part of preventing infection.

In principle, there are two main types of disinfection and sterilization methods: physical disinfection and chemical disinfection. Physical disinfection methods mainly include steaming, ultraviolet radiation, microwave treatment, etc. This method kills bacteria and viruses through physical effects such as heat and electromagnetic waves. Chemical disinfection methods mainly use chemical disinfectants to contact bacteria and viruses through spraying, wiping, soaking, etc., destroying their protein structure and genetic material, thereby killing bacteria and viruses. The disinfectants mentioned in this article are chemicals with such effects.

What kinds of household disinfectants are commonly used in our daily lives? What are their respective characteristics? How to choose the most suitable disinfectant? What matters need to be paid attention to when using it? Let me tell you one by one.

Chlorine-containing disinfectants

The 84 disinfectant we use to clean the bathroom on a daily basis is the same as the bleaching powder added to tap water, both of which are chlorine-containing disinfectants. The active ingredient of 84 disinfectant is sodium hypochlorite, and the active ingredient of bleaching powder is calcium hypochlorite, both of which are hypochlorites. These hypochlorites can produce hypochlorous acid in water. Hypochlorous acid is a weak acid with very unstable chemical properties. It can only exist in solution and has strong oxidizing properties. It can easily penetrate cell walls, damage cell membranes, release substances such as proteins and DNA, and affect a variety of enzyme systems, thereby killing bacteria. Therefore, the oxidizing effect of hypochlorous acid can be used for sterilization and disinfection. Obviously, the core component of chlorine-containing disinfectants is hypochlorous acid.

In addition, we usually see the term "effective chlorine" in the packaging instructions of chlorine-containing disinfectant products. It is an important indicator used to measure the content of active ingredients in chlorine-containing disinfectants. It is measured by measuring the amount of chlorine gas generated after the product undergoes a chemical reaction with dilute hydrochloric acid.

Chlorine-containing disinfectants have a certain pungent smell, are corrosive to metals, and have a bleaching effect on textiles. The concentration of chlorine-containing disinfectants used in daily life should not be too high, and the contact time with items should not be too long. Attention should be paid to washing away the residue with clean water in time. In addition, the chemical properties of chlorine-containing disinfectants are not very stable. In order to ensure their effectiveness, it is best to prepare them for use immediately and not store them for a long time.

Another thing to note is that you should never mix chlorine-containing disinfectants with acidic cleaners such as toilet cleaners, toilet cleaning blocks, and bathroom cleaners. This is because the hydrochloric acid in the acidic toilet cleaner (usually marked as an inorganic acid in the ingredient list) will react chemically with the chlorine-containing disinfectant to produce toxic gas with a pungent odor - chlorine gas.

Iodine-containing disinfectants

Elemental iodine is the main active ingredient in iodine-containing disinfectants. It has strong permeability and can oxidize and kill a variety of bacteria and viruses. It is mostly used for human skin disinfection.

There are two main types of iodine-containing disinfectants available on the market: tincture of iodine and iodophor. Tincture of iodine is obtained by dissolving iodine in alcohol, so it is also called iodine wine. Tincture of iodine has a strong bactericidal and disinfecting ability, and is also highly irritating to the skin. Therefore, tincture of iodine cannot be used for disinfection of mucous membranes and thinner skin. Iodine tincture has no irritating odor and is less irritating to the skin than tincture of iodine. This is because iodine tincture is an aqueous solution of a complex composed of iodine and a surfactant. On the one hand, iodine can be slowly released and can still play a good disinfection and sterilization role; on the other hand, using water as a solvent also reduces the irritation to the skin. Therefore, iodine tincture has more advantages in wound disinfection and sterilization.

Elemental iodine is volatile and sensitive to environmental factors such as light and heat. Therefore, iodine-containing disinfectants should be kept in a sealed, light-proof, cool place. If iodine tincture or iodine tincture is stored in the family medicine box for a long time, the packaging box may change color and even contaminate other medicines. In addition, iodine-containing disinfectants are brown and dark in color, so be careful not to contaminate items during use. Another point to note is that iodine-containing disinfectants are corrosive to metals and cannot be used to disinfect metal objects.

Peroxide disinfectant

Peroxides have strong oxidizing properties and can sterilize and disinfect through their own oxidation, and have a good killing effect on various microorganisms. Peroxide disinfectants include hydrogen peroxide, peracetic acid and ozone.

The advantages of peroxide disinfectants are that they are green, mild, and generally do not leave toxic residues. In hospitals and other medical institutions, peroxide disinfectants are usually used to disinfect wounds, etc. Peroxide disinfectants can also be used for household disinfection, such as disinfecting clothing and surfaces.

Commercially available hydrogen peroxide disinfectant, commonly known as hydrogen peroxide disinfectant, belongs to this category of disinfectants. The mass percentage of hydrogen peroxide it contains is 3%.

Careful people will find that when using hydrogen peroxide disinfectant to clean wounds and wipe the surface of objects, tiny bubbles will be produced, indicating that oxygen is released. In this process, oxidative free radicals can destroy the structure of bacteria and viruses, achieving the purpose of killing bacteria and viruses.

Although hydrogen peroxide disinfectant is colorless, odorless and easy to use, its properties are very unstable and it needs to be stored in a dark, cool and dry place away from fire and high-temperature objects. If people accidentally come into contact with hydrogen peroxide disinfectant during use, their skin may oxidize and turn white, and their skin may fall off, but this is not a big deal. In addition, hydrogen peroxide is corrosive to metals and cannot be used to disinfect metal objects.

It should be noted that although the toxicity of peroxide is very low, it may cause harm if used improperly. Peroxide disinfectants are strictly prohibited from being taken orally, and should be kept out of reach of children. Try not to mix them with other types of disinfectants.

When using peroxide disinfectants, personal protection should be taken. For example, when using peracetic acid disinfectants, rubber gloves must be worn when diluting and using them. Handle them with care during operation and avoid shaking the container violently to prevent the solution from splashing into the eyes, skin and clothing. The container for preparing disinfectant should preferably be plastic. When preparing peracetic acid, avoid mixing it with alkali or organic matter to avoid violent decomposition or even explosion.

If disinfectant comes into contact with your skin or eyes due to careless use, rinse it with clean water immediately. If the condition is serious, seek medical attention immediately.

Quaternary ammonium disinfectants

Quaternary ammonium salts are a type of cationic surfactants that are easily soluble in water and have the functions of sterilization, fabric softening, antistatic, flocculation, etc. The most representative quaternary ammonium salt disinfectant is Sanisol, which is an aqueous solution of dodecyl dimethyl benzyl ammonium bromide (benzalkonium bromide). It has a broad-spectrum bactericidal effect, is non-irritating to the human body, non-corrosive to metals, has decontamination ability, does not contaminate clothing, and is often used to disinfect human skin and immersion disinfection of medical devices.

It should be noted that quaternary ammonium salt disinfectants cannot be used at the same time as soap detergents. This is because the anionic surfactants in the soap will neutralize the cationic surfactants contained in Sanisol, causing it to become ineffective.

Biguanide disinfectants

Commonly used biguanide disinfectants include chlorhexidine gluconate aqueous solution, commonly known as chlorhexidine. Chlorhexidine is a colorless or light yellow solution, odorless, stable in nature, and durable in storage. It is mainly used for human mucosal flushing and disinfection and oral gargle sterilization, especially in the auxiliary treatment of oral ulcers and periodontal disease, with good results.

Chlorhexidine is similar to chlorhexidine, which is a cationic disinfectant. It cannot be used at the same time as detergents containing anionic surfactants (such as soap), nor can it be used with iodine or peroxide.

Since biguanide disinfectants are only effective against bacteria and some viruses, they are often used for disinfection of non-critical items in hospitals, hand skin, and daily household use. Chlorhexidine ointment used for mild, small-area burns and traumatic infections, as well as metronidazole chlorhexidine lotion commonly used in gynecology, are both such disinfectants.

Alcohol disinfectant

Alcohol is an aqueous solution of ethanol and belongs to the alcohol disinfectant. The ethanol content in medical alcohol is usually 75% (volume percentage).

Alcohol can quickly absorb the moisture of bacteria and virus proteins, causing them to denature and coagulate, thereby sterilizing and inactivating them. It has a significant bactericidal effect, fast action, stable properties, easy volatility, and no residue. It is a commonly used disinfectant in daily life and is widely used for disinfection and sterilization of human skin, surfaces of objects, and medical devices.

Alcohol disinfectants are flammable. When using and storing them, be careful to keep them away from open flames. Do not store them in large quantities at home to avoid fire safety hazards.

At present, the most commonly used disinfectant in our daily life may be alcohol disinfectant. In non-home occasions, such as taking buses, subways, or long-distance travel by train or plane, spray-type alcohol disinfectants are not suitable for safety reasons. Therefore, portable and safe alcohol disinfection products came into being. This type of disinfection products mainly includes hand sanitizers, disinfectant wipes and alcohol cotton pads. The ethanol content of alcohol-free hand sanitizers has been reduced, but it does not affect the sterilization effect. Alcohol-free hand sanitizers generally contain glycerin, propylene glycol, water and other ingredients to form a non-flammable viscous gel. When using, after rubbing your hands according to the specifications, you don’t need to wash them with water to achieve dryness and sterility, and your skin will not feel dry. Disinfectant wipes and cotton pads are soaked in alcohol on non-woven fabrics, which can be used directly to wipe the surface of objects, and of course they can also be used to wipe your hands. For our mobile phones that we never leave, it is both economical and convenient to wipe them with small pieces of alcohol cotton pads. Obviously, these new alcohol disinfection products are easy to carry and use, and are very suitable for use on the go.

Potassium permanganate disinfectant

Potassium permanganate is a black-purple crystalline particle, a strong oxidant, and a purple-red solution when dissolved in water. Potassium permanganate disinfectants available on the market are both solution-based and granular, commonly known as PP water or PP powder, and are usually used for sitz bath sterilization of gynecological and men's inflammation and hemorrhoids.

Since potassium permanganate disinfectant has a strong oxidizing effect on the skin, it should not come into direct contact with the skin, especially the mucous membrane. If it is accidentally splashed on the skin, the skin in contact will turn black and should be washed immediately with plenty of water. The blackened skin will fall off after a few days and there will be no major problems.

Potassium permanganate disinfectant is easily decomposed by light and needs to be stored away from light. It is best to prepare it before use.

In general, there are many types of household disinfectants, each with its own characteristics, advantages and disadvantages. Only by reasonable selection and scientific use can the best effect be achieved.