How does soap work?

Bacteria and microbes are everywhere. In the air, soil, water, on all surfaces, including the body. Most are harmless, and some are even important for health (such as those in our body). Bacteria can be active on our skin for hours, sometimes days.

Human skin is an ideal surface for them. It is organic, and proteins and fatty acids on the surface interact well with it. When you touch a surface with bacteria, it sticks to your hands, and with further contact with the face (eyes, nostrils, mouth) you can get infected. It turns out that most people touches their face every 2-5 minutes.

Our first line of defence against harmful germs is soap. Promoting hand washing helps prevent the spread of bacteria and the fact that there is currently no antidote to the current rampant coronavirus.

So why and how does soap work?

Soap doesn't kill bacteria on our hands, it removes them. Bacteria cling to oil and grease on the hands (gross, but perfectly normal :)) Water alone will not remove many bacteria because it repels oil (so they don't mix). Soap loves the combination of oil and water, acts as a mediator between them, and carries away bacteria when rinsed with water.

Since there are no strong bonds, a strong chemical is not needed to break them down. Disinfectants, gels and creams containing alcohol are useful in removing them, but not as much as regular soaps. In alcohol-based products (60% or more ethanol) you would basically have to bathe the bacteria, and even rubbing would not guarantee that the gel would get into every fold. Soap only needs a very small amount of water.

So using soap is the most effective (not just water!), but alcohol-based disinfectant is a good backup plan if soap is not available.

Our tip: Wash your hands as if you were just catching jalapenos and were about to change your contact lenses. :D