By Dr Denis Boulais, National Risk Manager, Broadlex Services
With the recent emergence of the coronavirus, an article on the fundamental cleaning element of handwashing is quite relevant. Handwashing programs in workplace settings have resulted in reduced sick days, according to some studies, with some communities experiencing cold and flu reductions of up to 21%, and gastrointestinal illnesses reducing by as much as 58%.
It is important that cleaners in facilities understand the difference between cleaning, sanitising and disinfecting, and how poor hygiene can compromise these processes.
Cleaning removes germs, dirt and other impurities from surfaces by using detergent (such as soap) and water to physically remove germs. It doesn’t necessarily kill the germs but rather lowers their numbers on the surface.
The terms ‘disinfectant’ and ‘sanitiser’ are regularly used interchangeably. Disinfection kills germs via the use of chemicals on surfaces. Disinfection doesn’t necessarily remove germs, but killing them certainly reduces their numbers. Sanitising, in comparison, significantly lowers germs on surfaces to a safe level with a fast kill.
In practicality, the food industry may benefit primarily from sanitisers. For example, when cleaning dishes, it is important to get an effective kill of germs fast so that dishes can be re-used as soon as required. The medical industry, however, may prefer disinfectants because they aim to kill specific germs specified on their label. Both the food and hospital industries are prime examples of where correct handwashing and good hygiene can reduce the spread of germs.
Poor hand hygiene can compromise the level of hygiene a facility is aiming to achieve. For example, when handling rubbish, a cleaner may come into contact with items such as tissues – noting that the flu virus can infect a person for up to eight hours after being deposited on a surface. It is always important that cleaners are trained to never put their hands where they cannot see them when handling rubbish, and to wash their hands as required.
There are a number of reasons cleaners may not follow a strict regime of washing their hands. These include:
- workload – when busy, a cleaner may be less likely to wash their hands
- time – there may not be enough time to wash their hands fully and properly
- appearance – their hands may not appear dirty, but germs are too small to be seen
- presence – a sink may be hard to get to, such as in a messy cleaning room.
Hence, it is important that cleaners and facilities managers are trained to understand that handwashing is a priority for their own health benefits, and that of their clients.
The art of handwashing
Soap acts as a detergent with one side of its molecule liking water (hydrophilic) and the other side of its molecule liking oil (hydrophobic). Cell membranes are also made up of a dual-sided hydrophilicand hydrophobic molecule. As such, soap solvates the hydrophobic parts of a cell membrane and hence kills the bacteria by dissolving the membrane. Furthermore, the hydrophilic part of the molecule then causes it to be easily washed away.
Soap isn’t as effective against viruses because viral membranes are more protein-based than lipid-based, and hence the viral membrane isn’t as easily dissolved. That said, however, a soapy environment can still adversely affect protein structure and inactivate a virus. Of course, alcohol-based hand sanitisers and antibacterial soaps are likely to be more effective than soap.
It is normal to have germs living on the skin. While soap and water do a good job of removing germs from the hands, it is important to ensure that hands are properly dried. It is more likely that wet hands will spread germs than dry ones. It takes around 20–30 seconds to dry hands well with paper towels and 30–45 seconds under an air dryer.
There are three important tips associated with washing hands:
- Don’t scrub your hands as this can damage the skin and potentially create small cuts for germs to enter.
- Try to keep your fingernails short as bacteria fester in the area under nails, and longer nails are harder to keep clean.
- Don’t be in a hurry as it takes around a minute to properly wash and dry hands.
Alcohol-based cleansers kill germs by denaturing (changing the shape of) proteins essential to the survival of viruses and bacteria. Most cleansers have a high level of alcohol (around 60 per cent) mixed in with skin conditioners, as alcohol itself would dry out the skin. Research has shown that alcohol-based cleansers have reduced germ counts on hands better than soap.
Alcohol, however, does not kill everything, such as bacterial spores and non-enveloped viruses. A non-enveloped virus is very virulent, can damage host cells significantly, and is more resistant to harsh environments than an enveloped virus with its membrane of lipids and protein. That’s why each environment needs to carefully assess its handwashing requirements. For example, many hospitals go back to soap and water cleaning during cold-weather vomiting outbreaks, which may be caused by non-enveloped and more virulent viruses.