During the current COVID-19 outbreak, people are being encouraged to wash their hands and sanitise frequently to limit the transmission of the virus. This is one of the most important means of managing our risk for any infection, which has been highlighted by the current situation. Recent evidence indicates that COVID-19 virus (SARSCoV-2) can survive on surfaces ranging from 2 hours to 9 days, depending on a number of factors. This means that you are at risk of being infected simply by touching a contaminated surface and then touching your face and contaminating the mucous membranes of your eyes, nose or mouth.

What is good hand hygiene?
Hand hygiene consists of either washing your hands with soap and water, or using an alcohol based hand rub, depending on the situation. Both are very effective in removing and killing microorganisms on your hands, including the SARS-CoV-2 virus, which causes the COVID-19 disease.

If you are washing your hands, normal soap is all that is required – there is no need for an antibacterial soap. The most important factors are washing all surfaces of the hands using soap and friction, caused by rubbing hands together for at least 20 seconds and then rinsing. Washing your hands is recommended if they are visibly soiled (with visible dirt or organic matter) or are aware that you have come into contact with body fluids – such as if you have covered your mouth or nose with your hand if you have coughed or sneezed.  Handwashing is also recommended after disposing of a tissue, on entering the home having come from public places.

The benefit of a good sanitiser is that it is “mobile” and available when soap and water may be difficult (e.g. to clean your hands in the car after shopping before removing your mask).

What are the properties of a good hand sanitiser and how should it be applied?
It is important to use an alcohol-based hand sanitiser that contains at least 60 - 70% alcohol that is still within its expiry date.  When using alcohol based hand rub, it is important to apply  a ‘palm full’ or a sufficient  amount to wet the entire surface of the hands  and to then rub all surfaces of the fingers and hands until your hands  are dry - approximately 20-30 seconds. As with hand washing it is important to rub all surfaces of the hands, in this case until all the handrub has absorbed. A good quality handrub will also contain emollients which prevent drying of the skin on the hands when rubbed in effectively.    

Should I make my own sanitiser if stocks are low?
No, it is not advisable to make your own handrub. With stocks running low in some retail stores many online instructions are available to produce your own sanitiser. However, many of these DIY instructions do not meet the lower limit of 60% alcohol, making them ineffective. Other recipes require use of alcohol with contents with up to 99% alcohol, which is usually very flammable and volatile, and evaporates fast, making it dangerous to work with. The recommendation is to rather choose a store purchased sanitiser with adequate alcohol concentration.

How does soap or sanitiser work to destroy the virus?
Washing your hands with soap and water removes any foreign material from your hands, including bacteria and viruses. The soap also kills the SARS-CoV-2 virus by destroying the surrounding capsule, also called an “envelope”.

Alcohol based hand rub is effective in killing the virus as it also destroys the surrounding protective capsule, however, if you have mucous or other body fluids on your hands, the alcohol won’t be able to penetrate it, and won’t be effective in removing the mucous or body fluids – which is why washing your hands in this situation is recommended.

(Source: WHO)