COVID-19: Out of Hand Sanitizer? No Problem. Here’s Why

23 March 2020

Around the age of 2, we begin to learn how to wash and dry our own hands. Isn’t it ironic that we need a crisis like this one (COVID-19), to go back to the basics? Hopefully people won’t forget this skill when the #coronavirus is not trending anymore.



Facts on Hand Washing



  • 19% of people wash their hands with soap after coming into contact with feces, according to an international study led by UK researchers in 20141. That’s 1 on 5. Spreading is inevitable with these kinds of habits.
  • An MIT (Massachusetts Institute of Technology) research article mentions: ‘’To slow epidemic, focus on handwashing’’.  This research also mentions that increasing hand washing in just 10 airports in the US would reduce the spread of the #COVID-19 (and other diseases) by 60%.2
  • The percentage of healthcare workers who comply with optimal hand hygiene practices is considered to be less than 40%.3

Handwashing education in the community can4:


  • Reduce the number of people who get sick with diarrhea by about 23-40%;
  • Reduces absenteeism due to gastrointestinal illness in schoolchildren by 29-57%;
  • Reduce diarrheal illness in people with weakened immune systems by about 58%;
  • Reduce respiratory illnesses, like colds, in the general population by about 16-21%.

Every October 15th, the CDC (Center for Disease Prevention and Control) celebrates Global Handwashing Day, highlighting the importance of handwashing with soap at home, in the community, and around the world. This celebration started way before COVID-19!



Handwashing with Soap and Water



Effectiveness of washing hands 

“Handwashing has been clearly shown to prevent a variety of diseases and is one of the most important ways to protect oneself and others from infections. To date, studies have shown that there is no added health benefit for consumers (this does not include professionals in the healthcare setting) using soaps containing antibacterial ingredients compared with using plain soap.” – CDC5


How to wash your hands with soap and water: 


  1. Take off your jewelry if you have any;
  2. Wet your hands with clean running water (warm or cold);
  3. Apply soap;
  4. Rub your hands together with the soap and scrub all surfaces of your hands (including the palms, backs, fingers, between your fingers, and under your nails.);
  5. Keep scrubbing for 20 seconds;
    1. Need a timer?
      1. You can ask Siri: “Hey Siri, count 20 seconds!” 🙂
      2. Sing Happy Birthday (not on speed mode), twice
  6. Rinse your hands under clean, running water;
  7. Dry your hands with a clean towel, paper towel, or air dry.



Image source: WHO6



Hand Sanitizers

Effectiveness of Hand Sanitizers 


  • Sanitizers do not get rid of all types of germs.
  • Hand sanitizers may not be as effective when hands are visibly dirty or greasy.
  • Hand sanitizers might not remove chemicals that are harmful to your hands, like pesticides and heavy metals.
  • A study suggests that the preferential use of alcohol-based hand sanitizer over soap and water for routine hand hygiene might be associated with increased risk of norovirus outbreaks in long term care facilities.7
  • Washing hands is more effective against Cryptosporidium, norovirus and Clostridium difficile for example.7
  • A study from the American Society of Microbiology8 mentions that ethanol-based disinfectants used against influenza A virus in infectious mucus are ineffective.
  • Effective, alcohol-based, hand sanitizers need to have a concentration of more than 60% alcohol to be effective against germs.

Small note: Alcohol may be expressed as “ethanol”, “isopropyl alcohol”, or “ethyl alcohol” on the bottles ingredient section.  

In other words, over-depending on hand sanitizers may be risky. Alcohol-based hand sanitizers remain an effective choice against many microbes, and, when used correctly. It is important to use enough volume of the sanitizer and do not wipe it off before it has dried.


How to use hand sanitizer:


  1. Make sure your hands are not very dirty and greasy. Otherwise, wash your hands with soap and water;
  2. Take off jewelry if you have any;
  3. Put enough product on hands to make sure all surfaces are covered;
  4. Rub your hands together, covering all surfaces of both hands, including between your fingers and up around your fingertips and nails. This should take around 20 seconds;
  5. Do not rinse or wipe off the hand sanitizer before it’s dry.



Hand drying

Transmission of bacteria is more likely to occur when the skin is wet or humid, as opposed to when it’s dry. Hand drying is an important part of hand hygiene.

Studies suggest that paper towels could reduce contamination of the washroom environment more than electric air dryers. Air dryers are still acceptable, but the use of paper towels is recommended in locations where hygiene is paramount, such as in hospitals or clinics.9-10





  • Hand sanitizers do work against COVID-19, but well-performed hand washing is better
  • Hand sanitizers are not effective against all microbes
  • If handwashing is not ‘’accessible’’, hand sanitizer should be used





  1. Systematic review: Hygiene and health: systematic review of handwashing practices worldwide and update of health effects
  2. To slow an epidemic, focus on handwashing: Improving the rate of handwashing at just 10 major airports could significantly slow the spread of a viral disease, researchers estimate
  3. Gautham Suresh, M.D., D.M., M.S., Cahill, John, M.D., “National Patient Safety Goals. How ‘User Friendly’ is the Hospital for Practicing Hand Hygiene?: An Ergonomic Evaluation.” The Joint Commision Journal on Quality and Patient Safety 33. 3 (March 2004) : 1.
  4. CDC: Global Handwashing Day | Handwashing
  5. Show Me the Science – When & How to Use Hand Sanitizer in Community Settings | Handwashing
  6. Clean hands protect against infection
  7. Use of alcohol-based hand sanitizers as a risk factor for norovirus outbreaks in long-term care facilities in northern New England: December 2006 to March 2007.
  8. Situations Leading to Reduced Effectiveness of Current Hand Hygiene against Infectious Mucus from Influenza Virus-Infected Patients
  9. The hygienic efficacy of different hand-drying methods: a review of the evidence.