The effectiveness of hand sanitizer against corona virus

Tests confirmed that two formulas of hand sanitizer recommended by the World Health Organization (WHO) inactivate the virus that causes the coronavirus disease 19 (COVID-19). The tests also provide reassurance that store-bought disinfectants combat the virus.

In the absence of a vaccine or effective antiviral drugs, hand hygiene is a mainstay of efforts to prevent the spread of Coronavirus Syndrome 2 (SARS-CoV-2), the virus that causes COVID-19.

Infected people may exhibit few, if any, symptoms but still be able to pass the virus on to others. The virus is spread through droplets in the air or on commonly used surfaces, such as doorknobs. Therefore, washing hands well with soap and water for at least 20 seconds is a very effective way to defend against harmful bacteria and viruses, including Corona virus.

However, hand washing is not always practical, especially for health care workers. This is due to the lack of access to water for hand washing and the lack of time to wash hands well.

Meanwhile, this group of people may be exposed to infections from a variety of sources throughout the day.

Alcohol-based hand sanitizers provide a quick and simple alternative. However, there was a lack of strong evidence that they are effective against the Coronavirus.

The guidelines have so far stemmed from research showing that disinfectants inactivate other coronaviruses.

Two formulas of hand sanitizer

The World Health Organization recommends two formulations of alcohol-based disinfectants to prevent the spread of pathogens in general. Scientists in Germany and Switzerland are also constantly testing the effectiveness of disinfectants against the Corona virus.

The first disinfectant consists of:

  1. 80% ethanol
  2. Glycerol 1.45%
  3. 0.125% hydrogen peroxide

The second disinfectant consists of:

  1. Isopropanol (also known as 2-propanol or isopropyl alcohol) 75%
  2. Glycerol 1.45%
  3. 0.125% hydrogen peroxide

The researchers revealed that the Corona virus particles remained for 30 seconds when using each of the two formulations. When they tested the virus’ subsequent ability to infect cells in laboratory cultures, they found that both formulas inactivated the virus.

This experiment was led by Professor Stephanie Pfander of the Department of Molecular and Medical Virology at the Ruhr Universität Bochum in Germany.

“We showed that both formulas recommended by the World Health Organization inactivate the virus adequately after 30 seconds,” says Professor Pfander.

Low inventory

The results of this study are particularly relevant because supplies of disinfectants were low worldwide during the coronavirus pandemic.

One of the advantages of this new study is that it gives community pharmacies and hospitals the green light to quickly and easily manufacture their own hand sanitizer using WHO formulations, confident that it will be effective.

The Centers for Disease Control and Prevention (CDC), in its advice to the public about hand hygiene, suggests that disinfecting hands with hand sanitizer should take about 20 seconds.

Active ingredients

The scientists also tested ethanol and isopropanol – the active ingredients for each formulation recommended by the World Health Organization – in isolation and at different concentrations. And their results indicate that either ethanol or isopropanol at a concentration of at least 30% is sufficient to inactivate the Corona virus.

For comparison, the CDC recommends that hand sanitizers contain at least 60% alcohol. The hand sanitizers sold in drugstores and supermarkets usually contain an alcohol concentration of about 60%.

However, locally made hand sanitizers without the necessary skills, equipment, and medical ingredients, may not contain alcohol concentrations high enough to inactivate the Coronavirus.

For example, pure rubbing alcohol or povidone has an alcohol concentration of about 70%. However, frequent use of rubbing alcohol on the hands can lead to dry skin, causing inflammation and irritation.