Thank you for bringing this up! Many hand sanitizers and household cleaners proudly claim to "Kill 99.99% of germs."
In fact, this does not mean that the product kills 99.99% of all germs known to exist.
It means that, during product testing in a controlled environment, the product killed 99.99% of the germs it was specifically tested against. As you might imagine, Lysol isn't testing its kitchen disinfectant spray against millions and millions of unique microbes.
In the U.S., labeling laws usually require that companies actually identify somewhere else on the label which germs are being tested and killed. Next time you see a "kills 99.99% of germs" label, check out the rest of the label, and you'll find the small print which specifies that it kills 99.9% of one type of flu, or Covid, or E. Coli, etc. This is why many labels even include an asterisk, i.e.: "Kills 99.99% of Germs!*" Look for the companion asterisk elsewhere on the label for more info.
There are different kinds of germs, like Viruses; Bacteria, Fungi, and Protozoans.
The way we kill these germs to prevent infections varies based on the germs' structure. Essentially, we need different "weapons" (cleaning methods) to fight different microbes. A product that kills Flu Viruses and E. Coli can't necessarily destroy Norovirus or Giardia.
No product is effective against every type of germ, even common germs which regularly cause illness in households and communities.
Hand washing is effective against more germs, not only because it can destroy germs which hand sanitizer cannot, but because it simply washes them off your hands.
More on the many personal, community, & global benefits of hand washing.
