The new coronavirus is threatening, but it is still preventable and controllable. Taking effective preventive measures, wearing masks, washing hands frequently, and disinfecting the environment where you live and live are all very effective methods.
Coronaviruses are a class of RNA viruses with an envelope. When the envelope is destroyed by disinfectants, the RNA is also easily degraded, thereby inactivating the virus. Due to this envelope, the coronavirus is sensitive to chemical disinfectants, and 75% alcohol, ether, chloroform, formaldehyde, chlorine-containing disinfectants, peracetic acid, and ultraviolet rays can inactivate the virus. In addition, a certain temperature can also inactivate the virus. The coronavirus can survive for 4 days at 37°C. Heating at 56°C for 90 minutes and heating at 75°C for 30 minutes can inactivate the virus.
1. Common chemical disinfectants
Commonly used chemical disinfectant products can be divided into 8 types according to their components: alcohol-based disinfectants, chlorine-containing disinfectants, peroxide-based disinfectants, biguanide-based disinfectants and quaternary ammonium salt-based disinfectants, iodine-containing disinfectants, and aldehydes. Disinfectants, phenolic disinfectants, ethylene oxide.
1) Alcohol disinfectant (alcohol)
Chemical composition: Ethanol.
Disinfection principle: 95% alcohol can quickly solidify the protein enveloped on the surface of bacteria, and form a protective film to prevent alcohol from entering the bacteria, so it cannot completely kill the bacteria. If the alcohol concentration is lower than 70%, although it can enter the body of bacteria, it cannot coagulate the protein in its body, nor can it completely kill the bacteria. Only 70%-75% alcohol can enter the bacteria smoothly, and can effectively coagulate the protein in the bacteria, so it can completely kill the bacteria. Therefore, WHO recommends 70%-75% ethanol as a hand sanitizer.
Disinfection method: soak, wipe.
Precautions: Alcohol is a flammable and volatile liquid. When the alcohol content in the air reaches 19% and the temperature is equal to or greater than 13°C, it will flash when it encounters sparks. Remember to keep away from fire when using it. Thoroughly remove the surrounding flammable and combustible materials before use, and do not touch or close to open flames when using. After use, the lid of the container must be closed, and it is strictly forbidden to leave it open. Use cloth cleaning tools such as towels, wash them with plenty of water after use, and store them in an airtight area, or let them dry in a ventilated place. When alcohol disinfection is required at home, you can purchase small bottles of alcohol (≤500ml) for use. Do not hoard alcohol in your home. The alcohol container must have a reliable seal, and it is strictly forbidden to use a container without a lid. Store away from fire and heat sources, the temperature should not exceed 30 ℃, and prevent direct sunlight.
Other information: Alcohol is not suitable for large-area disinfection and spraying, spray disinfection.
2) Chlorine-containing disinfectants (84 disinfectant, bleaching powder, chlorine-containing disinfection powder, Jianzhisu effervescent disinfection tablets, etc.)
Chemical composition: sodium hypochlorite, calcium hypochlorite, trisodium chlorinated phosphate, sodium dichloroisocyanurate, trichloroisocyanuric acid, ammonium chloride T, etc.
Disinfection principle: The molecular weight of hypochlorous acid is small, which is easy to diffuse to the surface of bacteria and penetrate the cell membrane into the bacteria, so that the bacterial protein is oxidized and the bacteria die. Chlorine-containing disinfectants kill a variety of microorganisms, including bacterial propagules, viruses, fungi, Mycobacterium tuberculosis, and the most resistant bacterial spores.
Disinfection method: soaking, spraying, spraying, wiping.
Matters needing attention: Chlorine-containing disinfectants are irritating and corrosive to a certain extent. They must be diluted before use (according to the instructions). Wear gloves when using to avoid contact with the skin. Chlorine-containing disinfectants have strong bleaching and corrosive effects, can corrode metals, and have a bleaching effect on fabrics. When it must be used for disinfection of clothing, the concentration should be low, and the soaking time should not be too long. Chlorine-containing disinfectants, if used improperly, such as mixing with acidic substances, such as vinegar or toilet cleaner, can easily generate chlorine gas and cause chlorine gas poisoning. Chlorine-containing disinfectants are easily decomposed and easily affected by light, heat and humidity, and lose their active ingredients.
Other information: It cannot be used together with disinfection and cleaning products such as toilet cleaners, as it will generate toxic chlorine gas and endanger human health. It is not recommended to use with alcohol, avoid skin, eyes, mouth and nose, wear masks, rubber gloves and waterproof apron when using. Hot water will affect the sterilization effect.
3) Peroxide disinfectants (hydrogen peroxide, chlorine dioxide effervescent tablets, peracetic acid)
Chemical composition: peracetic acid, hydrogen peroxide (hydrogen peroxide), chlorine dioxide and ozone, etc.
Disinfection principle: Peroxide-based disinfectants have strong oxidizing ability, and various microorganisms are very sensitive to them and can kill all microorganisms. Chlorine dioxide has strong adsorption and penetration ability to the cell wall, and releases atomic oxygen to oxidize sulfhydryl-containing enzymes in cells to play a bactericidal effect.
Peracetic acid is a high-efficiency peroxide disinfectant. The gas and solution of peracetic acid have strong bactericidal ability, which can kill bacterial propagules, mycobacteria, bacterial spores, fungi, algae and viruses, and can also destroy Bacterial toxin, its bactericidal effect is stronger than that of hydrogen peroxide, and its spore-killing effect is rapid.
Disinfection method: soaking, spraying, spraying, wiping.
Matters needing attention: Oxygen is released when the temperature is high, and a strong explosion occurs when heated to 110 °C. When the concentration of peracetic acid is greater than 45%, there is a danger of explosion caused by handling, vibration, heat or the presence of metal ions or contact with reducing agents. . Peracetic acid is strongly irritating to the skin, eyes and upper respiratory tract, has a burning effect on skin and mucous membranes, and has a strong corrosive effect on cotton wool fabrics and metals. Peracetic acid is unstable in storage and cannot be used for ground disinfection. Peracetic acid has obvious damage to the floor of materials such as marble and terrazzo, and its aqueous solution should not be used to wipe the floor. The high concentration of chlorine dioxide liquid is highly corrosive and irritating. Be careful not to splash into the eyes and skin when using it. If accidentally splashed, rinse immediately with water. However, due to the strong oxidizing power of chlorine dioxide, it should be avoided in high concentrations (>500ppm).
Other information: Air disinfection has limited effect in the control of respiratory infectious diseases. It is meaningful in terminal disinfection after confirmed or suspected cases are transferred away. It is recommended that professional health personnel use peracetic acid or hydrogen peroxide in an unmanned state. Disposal or mobile UV disinfection.
4) Biguanide and quaternary ammonium salt disinfectants (chlorhexidine (chlorhexidine), picowashidine)
Chemical composition: polyhexamethyl biguanide, poly-2-ethoxyethyl guanidine chloride, poly-6 methylene diamine guanidine chloride, chlorhexidine acetate, chlorhexidine hydrochloride, chlorhexidine gluconate.
Disinfection principle: Biguanide and quaternary ammonium salt disinfectants are both cationic surfactants. These compounds can change the permeability of bacterial cell membranes, make bacterial cytoplasmic substances extravasate, hinder their metabolism and play a killing role. Biguanides have a strong bactericidal effect on bacterial propagules, but cannot kill bacterial spores, mycobacteria and viruses. For skin and mucous membrane disinfection, can also be used for surface disinfection.
Disinfection methods: soaking, wiping, hand disinfection, skin disinfection.
Matters needing attention: Biguanide and quaternary ammonium salt disinfectants belong to non-toxic grades, which do not damage the environment and items. But it is a kind of inefficient disinfectant.
Other information: Biguanide and quaternary ammonium salt disinfectants are often compounded with other disinfectants to improve their bactericidal effect and sterilization speed. They are dissolved in ethanol to enhance the bactericidal effect. They are used for non-critical items and hand skin in hospitals. disinfect. But it does not kill bacterial spores.
5) Iodine-containing disinfectants (iodine tincture, iodophor)
Disinfection principle: The unstable complex of iodine and surfactant can release free iodine when it comes into contact with cells and bacteria. Free iodine can quickly penetrate the cell wall, relying on the precipitation and halogenation of elemental iodine, and The combination of hydroxyl, amino, and hydrocarbon groups on protein amino acids leads to protein denaturation, precipitation, and halogenation, thereby losing biological activity.
Disinfection methods: soaking, wiping, hand disinfection, skin disinfection.
Matters needing attention: Iodine tincture is simple in process and easy to make. It was the main disinfectant in the early days, but due to its irritation and corrosiveness, it has been gradually replaced by iodophor with good stability and less irritation.
Other information: Iodine-containing disinfectants can kill bacterial propagules, fungi and some viruses, and are mostly used for disinfection of skin and mucous membranes. Hospitals are often used for disinfection of hand skin, but like alcohol-containing disinfectants, it cannot kill. Germs or bacterial spores.
6) Aldehyde disinfectants (formalin)
Chemical composition: formaldehyde, glutaraldehyde, phthalaldehyde, etc.
Disinfection principle: This type of disinfectant is an active alkylating agent, which can kill various pathogens, and can act on the amino, carboxyl, hydroxyl and sulfhydryl groups in pathogen proteins, thereby destroying protein molecules and causing their death.
Disinfection method: fumigation.
Note: Because of its carcinogenic effect on the human body, it is easy to cause the death of skin epithelial cells and lead to paralysis and death. It cannot be used for disinfection of air and tableware.
Additional information: Pharmaceutical companies often use formaldehyde fumigation for environmental disinfection in clean areas.
7) Phenolic disinfectants (lysol, cresol soap solution)
Chemical composition: phenol, methyl phenol, hexachlorophenol, p-chlorometa-xylenol, trichlorodiphenyl ether, etc.
Disinfection principle: At high concentrations, phenols can lyse and penetrate the cell wall, causing bacterial proteins to aggregate and precipitate, quickly killing cells; at low concentrations, the enzyme system of bacteria can be inactivated, resulting in cell death.
Disinfection methods: soaking, wiping, hand disinfection, skin disinfection.
Matters needing attention: It cannot be used for disinfection of air, tableware, etc. It is generally only used for disinfection or sterilization of medical equipment in hospitals, and the sterilized or sterilized items must be rinsed with sterilized water after the residual disinfectant is cleaned. use.
Other information: Phenolic disinfectants are acid compounds, which are weakly acidic. They generally have a special aromatic odor and are easily oxidized in the environment. Therefore, care should be taken to avoid contact with alkaline substances during use.
8) Ethylene oxide
Chemical composition: Ethylene oxide.
Disinfection principle: It is a high-efficiency disinfectant, does not corrode metal, has no residual odor, and can kill bacteria (and its endospores), mold and fungi. It has strong penetrating power, and is often used for disinfection or sterilization after packaging of leather, plastic, medical equipment, and medical supplies, and it does not damage most items.
Disinfection principle: fumigation.
Precautions: Ethylene oxide is toxic, carcinogenic, irritating and sensitizing, and is a flammable and explosive chemical, so it is not commonly used in daily disinfection. In case of accidental contact with human body, it should be dealt with immediately.
Additional Information: Not suitable for household disinfection.
Post time: Jan-22-2022