When it comes to medical alcohol, everyone is familiar with it, which is a disinfectant medicine commonly available in small family medicine boxes and medical institutions. During the covid-19 pandemic, hand hygiene is an important part of disease prevention. Among the various types of disinfectants, the power of alcohol should not be underestimated. However, many people have a cognitive misunderstanding about alcohol, that is, "the higher the alcohol concentration, the better the disinfection effect." In fact, the concentration of disinfection alcohol should be between 70% and 75%, and the alcohol concentration is too high, which is not conducive to the penetration of alcohol into the interior of the pathogen and cannot achieve the disinfection effect.
Figureworm creative
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The invincible disinfectant power of alcohol
The biggest advantage is that the killing range is wide enough
Hand hygiene practices include handwashing with soap and water, hand sanitizer (alcohol-based hand sanitizer, etc.), foam or gel hand sanitizer, etc. Alcohol is increasingly favored by everyone because of its ease of use, non-staining, acceptable odor, fast start-up and wide range of antibacterial activity.
The most prominent advantage of disinfection with alcohol is that it is effective against a variety of pathogens. According to the Centers for Disease Control and Prevention (CDC), alcohol is effective against most Gram-positive and Gram-negative bacteria, including multidrug-resistant pathogens, HIV, influenza viruses, cowpox, hepatitis B and C viruses, among others. Experiments have shown that alcohol is very effective in preventing seasonal influenza, H1N1 and other viral and bacterial-based diseases.
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The alcohol concentration is too high
It will affect its permeability
Protein denaturation is the main way alcohol fights microbes. Alcohol will change the spatial structure of pathogenic proteins, irreversibly denature, coagulate, resulting in the loss of activity of structural proteins and functional proteins, thereby seriously damaging pathogenic microorganisms.
At the same time, alcohol can also destroy the cell wall of bacteria. Alcohol has a strong osmotic effect, and at a concentration of 60%-80%, this osmotic effect is the best, can enter the pathogen, destroy the integrity of the pathogen, resulting in pathogen lysis. However, when the concentration reaches 90%, the disinfectant effect of alcohol will be reduced. This is because too high a concentration of alcohol will make the protein on the outer surface of the pathogenic microorganism coagulate quickly, forming a protective shell on the surface of the pathogenic microorganism, preventing alcohol from further entering the inside of the microorganism, and cannot effectively exert the disinfection ability of alcohol.
In addition, alcohol can interfere with the enzyme system of microorganisms. Enzymes are indispensable catalysts for the normal physiological activities and metabolism of various organisms. Studies have shown that ethanol can interfere with pathogen metabolism through direct effects on the pathogen enzyme system.
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Different concentrations of alcohol
Determines the occasion when it comes into play
Alcohol commonly used in hospitals includes two concentrations of 75% and 95%, and alcohol used for usual disinfection is 75% concentration, which is often used for disinfection of skin and medical devices. It is worth noting that alcohol has a certain irritation and cannot be used for the disinfection of mucous membranes and large wounds.
95% alcohol is commonly used as fuel, found in various alcohol lamps, alcohol stoves, and can also be used in the fixation and dehydration steps of pathological tissue sections. In addition, 40%-50% alcohol can be used to prevent pressure sores. Patients who are bedridden for a long time due to long-term compression of local tissues, local tissues continue to bechemic, hypoxic, malnutrition, prone to pressure sores, once formed, it is difficult to heal. The use of alcohol when turning over and scrubbing can promote local blood circulation and help prevent the occurrence of pressure sores. Alcohol also has the effect of evaporating heat dissipation and promoting vasodilation, so 20%-50% alcohol is often used for physical antipyretics.
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Proper use of alcohol
Play its part better
It should be emphasized that liquor cannot replace medical alcohol. The alcohol concentration of the vast majority of liquor is about 20%-65%, while the recommended concentration of medical alcohol for disinfection is 70%-75%. Liquor can not achieve the effect of medical alcohol to kill microorganisms, but in the absence of alcohol, liquor can be used as an emergency treatment for disinfection.
During the epidemic, some people will spray alcohol in the room to achieve disinfection, but this is not necessary. The Centers for Disease Control and Prevention (CDC) has made it clear in the Environmental Guidelines and the 2008 Disinfection and Sterilization Guidelines that alcohol is not recommended for environmental disinfection. This is because the disinfection area is too large, the alcohol evaporation rate is fast, and the contact time with the surface of the object is short, and the good disinfection effect cannot be achieved.
Recently, in some areas, the NEW CROWN epidemic has fluctuated again, and we must be diligent, wash our hands frequently and minimize going out, while striving to strengthen our own immunity and not gather in dense crowds. Wearing a mask when going out is the top priority to prevent the new coronavirus, and if conditions permit, it is recommended to use alcohol reasonably for disinfection to protect yourself and your family.
Author | Wenzhen Gao, School of Stomatology, Shandong University
Yibo Wu, Department of Pharmaceutical Affairs Management and Clinical Pharmacy, School of Pharmacy, Peking University
Audit | Tang Qin, researcher of the Department of Science and Technology Popularization of the Chinese Medical Association
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TODD, EWEN C. D, MICHAELS, BARRY S, HOLAH, JOHN,等. Outbreaks Where Food Workers Have Been Implicated in the Spread of Foodborne Disease. Part 10. Alcohol-Based Antiseptics for Hand Disinfection and a Comparison of Their Effectiveness with Soaps[J]. J Food Prot, 73(11):2128-2140.
Boyce J M . Alcohols as Surface Disinfectants in Healthcare Settings[J]. Infection Control and Hospital Epidemiology, 2018, 39(3):1-6.Efficacy of ethanol against viruses in hand disinfection
Larson, Elaine L, Cimiotti, Jeannie, Haas, Janet,等. Effect of Antiseptic Handwashing vs Alcohol Sanitizer on Health Care–Associated Infections in Neonatal Intensive Care Units[J]. Arch Pediatr Adolesc Med, 159(4):377.
Maiwald M , Chan E S Y . The Forgotten Role of Alcohol: A Systematic Review and Meta-Analysis of the Clinical Efficacy and Perceived Role of Chlorhexidine in Skin Antisepsis[J]. PLOS ONE, 2012, 7.
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The correct use of alcohol should be remembered