Preparations for disinfecting hands are designed to destroy microorganisms. Alcohol-based liquids, gels and foams are the most effective. They have a broad biocidal effect and disinfect within 30 seconds. From what diseases can they protect us?

Antibacterial liquidsand otherpreparations for disinfecting handshave a disinfecting effect. This means that they destroy most of the pathogenic microbes on our hands to prevent infection. To be effective, they should contain 60-80 percent alcohol1 .

Disinfection is a process by which the vegetative forms of microorganisms are destroyed (however, it leaves behind bacterial spores and lentiviruses, causing disease after a long latency period). In addition to the vegetative forms, high-degree disinfection also destroys mycobacteria, enteroviruses and some spore forms.2

Preparations for disinfecting hands: types

Antibacterial and disinfecting preparations are in the form of a liquid, gel or foam. You can also find wet wipes soaked in alcohol, useful e.g. when traveling, when there is temporarily no access to running water and soap.

It should be remembered, however, that disinfectants do not remove visible dirt on the hands, they do not remove it mechanically like soapy water, which reduces their disinfecting effect.

Hand disinfectants: what do they need to contain to be effective?

First of all, they must contain alcohol. Alcohols used in hand sanitizers are ethyl and isopropyl alcohol. Also n-propanol is mentioned.

The proper concentration of these alcohols is 60-80 percent. Paradoxically, a higher alcohol concentration in the preparation causes a lower biocidal potential. This is due to the fact that the structures of proteins (bacteria, fungi, viruses) are more easily damaged (denatured) irreversibly in the presence of water1 .

Alcohols are characterized by a rapid bactericidal activity (even 10 seconds), they are able to inactivate mycobacteria, viruses and fungi, but do not destroy bacterial spores.

As prof. Didier Pittet, co-chairman of the 1st International Conference on the Prevention and Control of Infections (ICPIC), author of the "Geneva model of hand hygiene", only 30 seconds is needed for an alcoholic preparationdisinfect your hands and destroy harmful microorganisms.3

In addition to alcohol, antibacterial gels available in drugstores contain moisturizing substances such as aloe extract, glycerin, panthenol, thickeners (carbomer), fragrances, dyes and sometimes preservatives.

Preparations for disinfecting hands: what bacteria and viruses are they active against?

Preparations for disinfecting hands show a bactericidal effect (against gram-positive and negative bacteria), they are active against fungi. They may show full or partial virucidal activity.

The main factor determining the susceptibility of viruses to biocidal products is their structure: the presence or absence of an envelope. Virucidal efficacy is based on the activity against non-enveloped (i.e. hydrophilic) viruses. Hydrophilic viruses are much more resistant than lipophilic or enveloped viruses.

Ethyl alcohol (in a concentration of 60-80%) is active against lipophilic viruses (e.g. influenza viruses, herpesviruses, e.g. HSV) and most hydrophilic viruses (e.g. adenoviruses, parvoviruses, noroviruses, enteroviruses, rhinoviruses, rotaviruses) ), but does not destroy hepatitis A (HAV) and polio viruses.

Isopropyl alcohol is not active against enteroviruses.2

On the packaging of antibacterial gels you can, inter alia, read about destroying bacteriaE. Coli , salmonella, swine flu virus A / H1N1, rotavirus.

In areas affected by the COVID-19 coronavirus outbreak, the WHO recommends using alcohol-based disinfection gels and sprays as often as possible, after washing your hands with warm, running water and soap.

Hand disinfectants: how to disinfect your hands

On washed and dried hands, squeeze enough disinfectant to cover the skin surface of both hands. Then you need to thoroughly rub the preparation into all surfaces of both hands: the inside, back of the hand, spaces between the fingers, thumbs. Remnants of the agent, do not wipe off, just allow to dry. It only takes 30 seconds and it's ready.

Preparations for disinfecting hands: which reduces their effectiveness

The basic mistake is washing hands too rarely and disinfecting them. It can also be done in the wrong way (too short, avoid some parts of the skin). Wearing jewelry is also a problem, because underneath it we will not remove microorganisms during disinfection, as well as too long nails, painted nails (no dirt is visible under the nail with enamel). You should also not skip the hand washing step.

Preparations for disinfecting hands versus soapy water

Normal soap washes awaygrease, dirt, soil, substances of organic origin. Such soap does not work, or it has a minimal effect, on microorganisms, although it can remove the bacterial flora that is loosely attached to the skin.

Studies have shown that just 15 seconds of washing your hands with soap and water reduces the number of bacteria on the skin by removing them mechanically.

Washing your hands for 30 seconds (GIS recommended time) further reduces this number, but does not completely eliminate it. However, soap does not adequately remove pathogens from he althcare workers, as studies have shown1. Therefore, disinfection with the use of alcohol-based or alcohol-based preparations has been recognized as the basic method of decontamination of medical personnel's hands.2

Alcohols in antibacterial fluids are active against gram-positive and negative bacteria,M. tuberculosisand different types of fungi, as shown by testsin vitro , and also for most viruses .

Alcohol-based antiseptics do not remove visible dirt from the hands. Washing hands with water and soap (regular or antibacterial) removes impurities mechanically, but does not deprive the skin of all pathogenic microorganisms.

So, for your hands to be properly disinfected, first wash them with water and soap to remove mechanically visible dirt, and with them some microorganisms, and then disinfect them with an alcohol-based disinfectant.

According to an expertKarolina Karabin, MD, PhD, molecular biologist, laboratory diagnostician, Cambridge Diagnostics Polska A biologist by profession, specializing in microbiology, and a laboratory diagnostician with over 10 years of experience in laboratory work. A graduate of the College of Molecular Medicine and a member of the Polish Society of Human Genetics. Head of research grants at the Laboratory of Molecular Diagnostics at the Department of Hematology, Oncology and Internal Diseases of the Medical University of Warsaw. She defended the title of doctor of medical sciences in the field of medical biology at the 1st Faculty of Medicine of the Medical University of Warsaw. Author of many scientific and popular science works in the field of laboratory diagnostics, molecular biology and nutrition. On a daily basis, as a specialist in the field of laboratory diagnostics, he runs the content department at Cambridge Diagnostics Polska and cooperates with a team of nutritionists at the CD Dietary Clinic. He shares his practical knowledge on diagnostics and diet therapy of diseases with specialists at conferences, training sessions, and in magazines and websites. Particularly interested in the influence of modern lifestyle on processesmolecular in the body.

What to consider when choosing a disinfectant liquid?

First of all, composition. It is essential that the hand sanitizer contains alcohols (ethanol, isopropanol or a mixture of them) in an optimal concentration between 60 and 80%.

When is the disinfectant liquid effective?

After selecting the preparation, the method of its use is important. An appropriate amount of the preparation should be applied to the hand, which will be able to reach all corners of the hand. It is best to remove all jewelry from your hands before disinfecting. We should also remember that the disinfectant liquid must remain on our hands for at least 30 seconds to be effective. Ideally, before using the liquid, you should also wash your hands thoroughly with soap and water.

Does the addition of glycerin to the disinfectant reduce skin dryness?

Yes, skin moisturizers such as glycerin are added to hand sanitizers. According to the WHO report, the drying effect of alcohol can be reduced or eliminated by adding 1-3% glycerin to the hand sanitizer. Glycerin is used because it is not toxic and does not cause skin allergies.

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