Do normal hand soaps actually kill germs? We are always encouraged to wash our hands after a visit to the toilet, but does this really make much difference?

Ordinary soap has little value as an antiseptic and it does not kill or inhibit many types of bacteria.

However, the important function of washing one’s hands with soap is the mechanical removal of bacteria through scrubbing.

 The skin normally contains dead cells, dried sweat, bacteria, oily secretions and dust. In addition, having been to the toilet one would probably have contaminated his hands with faecal bacteria.

 Soap emulsifies the mixture of all these and the water washes it away. Because soaps are good for physically removing bacteria from the skin it is important to wash the hands before eating and after going to the toilet.

This prevents the transfer of potentially harmful bacteria by the faecal to oral route.

Cosmetic soaps contain antimicrobial compounds that strongly inhibit gram-positive bacteria and these are used to decrease body odour by preventing microbial growth on body secretions. These are non-household soaps that do contain some type of antibacterial compound.

These compounds act as disinfectants and kill bacteria. Of course, during our everyday activities we do not need or want to completely disinfect or sterilize our skin because the normal population of bacteria on us acts as a barrier against infection by pathogens. Healthy skin is a bacterial battleground populated with friendly bugs. These eat our sweat and, defend our skin from less friendly bugs that would not only eat our sweat but us as well.

Staphylococcus aureus is a typical invader that causes pimples and boils (or worse) when it beats our defenses. When we wash, we not only remove dirt and invasive bacteria, we also release a tide of friendly bugs from pores to recoat our skin for protection. This is fine unless you work in food preparation, you will then be required to use soaps that contain broad spectrum bactericides that kill all types of bacteria indiscriminately. Effective hand washing depends on many factors – the soap or cleaning agent, running water, clean towel or air drier for drying and on good technique.

Normal hand soap can remove germs, if used properly, and left to drain and dry between uses, not left sitting in a puddle of soggy soap and stagnant water. Pump dispensers are generally better than soap bars. Water must be clean and taps must not be contaminated by dirty hands – that is why hospital sink taps have elbow levers or, more rarely, foot pedals.

 Effective rinsing and drying, to remove any contaminated water without adding further contamination from a damp towel, are vital components of proper hand washing technique. This is why disposable paper towels are usually used in hospitals. Studies on hand-washing techniques by nurses have shown that some areas of the hand are less well-cleaned than others – fingers and the web between thumb and first finger are commonly inadequately leaned.a