Soap dispenser and hand sanitizers is hot now
Since the outbreak of COVID-19, sales of hand sanitizers and soap dispenser have soared. It’s become such a sought-after product that pharmacies and supermarkets have started limiting the number that people can buy at one time. Though hand sanitizers can help reduce our risk of catching certain infections, not all hand sanitisers are equally effective against coronavirus.
As with other viral respiratory attacks – like the common cold and flu – the novel coronavirus is mainly spread when virus-laden droplets from a person’s mouth or nose are transferred to other people. However, a recent study has suggested that it can also spread through feces.
Aside from inhaling droplets, you can also get respiratory viruses including SARS-CoV-2 by touching anything contaminated with the virus and then touching your face, in particular your mouth or nose. We touch our faces a lot without even realising it. A study found that people contact their faces about 23 times an hour.
Washing with warm water and soap remains the gold standard for hand hygiene and preventing the spread of infectious diseases. Washing with tepid to warm water (not cold water) and soap removes oils from our hands that can harbor microbes.
Advantages of alcohol
But hand sanitizers can also protect against disease-causing microbes, especially in situations when soap and water aren’t available. They’re also proven to be effective in reducing the number and type of microbes.
There are two main types of hand sanitisers: alcohol-based and alcohol-free. Alcohol-based hand sanitisers contain varying amounts and types of alcohol, often between 60% and 95% and usually isopropyl alcoholic beverages, ethanol (ethyl alcohol) or n-propanol. Alcohol is known to be able to kill most germs.
Not only are alcohol-based hands sanitisers found to work at killing many types of bacteria, including MRSA and E coli, they’re also effective against many viruses, including the influenza A virus, rhinovirus, hepatitis A virus, HIV, and Middle East respiratory syndrome coronavirus (MERS-CoV).
Alcohol-free hand sanitizers contain something called quaternary ammonium compounds (usually benzalkonium chloride) instead of alcohol. These can reduce microbes but are less effective than alcohol.
Destroying viruses
Alcohol attacks and destroys the envelope protein that surrounds some infections, including coronaviruses. This protein is vital for a virus’s survival and multiplication. But a hand sanitiser needs to be at least 60% alcohol in order to kill most viruses.
Hand sanitisers with less than 60% alcohol were also found to be less effective at killing bacteria and fungi and may only reduce the growth of germs rather than killing them outright.
And even hand sanitizers containing 60% alcoholic beverages can’t remove all types of germs.
Soap (Spray) and Gel is better if hands are visibly dirty
Studies have found that handwashing is more effective than hands sanitizers at removing norovirus, Cryptosporidium (a parasite that can cause diarrhoea), and Clostridium difficile (bacteria which trigger bowel problems and diarrhea).
If hands are visibly dirty, hand washing with soap and water is more effective than using alcohol-based hands sanitisers. Research has found that the detergent effect of soap and the friction of washing work together to reduce the number of microbes on our hands, as well as the dirt and organic materials.
Sneezing or coughing into your hands also requires more than just a pump of hand sanitiser to disinfect them. This is because if your hands are contaminated with mucous, the hand sanitiser might not work as well because mucous acts to protect microbes.
As a result, the best and most consistent way of preventing the spread of the coronavirus – and reducing your risk of contracting it – remains washing the hands with soap and water as a first choice, and avoiding touching your face as much as possible.
But alcohol-based hands sanitisers (with at least 60% alcohol) are a practical alternative when soap and water aren’t available. If you are using hand sanitiser then, just like when cleaning with soap and drinking water, you need to make sure you cover your hands (including between your knuckles, wrists, palms, back of your hand and your fingernails) fully, rubbing it in for at least 20 seconds so it’s truly effective.
