The claim to kill almost every germ is purely a marketing tool.
The claim by manufacturers using 99.9% or 99.99% is a powerful psychological tool, more powerful than saying “highly effective against”. Manufacturers are able to make this claim because they test products on an inanimate surface. This removes many of the variables that living tissue would provide, as the inanimate surface provides uniformity and easily controlled variables.
The test surface (even if it is hands) is cleaned before being smeared with the target organism – very different from the circumstances in which people find their hands daily. Simply put, the 99% claim leaves the manufacturers with a margin for error if someone becomes ill in spite of using their product.
Four out of 5 germs are spread by hands. Hand sanitisers and waterless cleaners mostly contain a high percentage (70%) of alcohol, which is proven to be most successful against bacteria and viruses. Research shows that while hand sanitisers do reduce the amount of
bacteria and viruses, as well as being less damaging to the skin, they are also ideal to use when soap and water aren’t available, but should not replace soap and water entirely.