Eighty million. That’s the number of germs exchanged in a kiss. Ten to two hundred million. That’s the number of germs that are found on an average cell phone.
What is a clean freak to do? How can we possibly combat all of those germs? This question comes from listener Geraldo in Brazil and I think it’s a great one. Does soap really kill 99.9% of germs?
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
How Does Soap Clean?
Remember that a germ is what we call any microscopic particle or organism that can make us sick, so this includes viruses and bacteria. Most of the gunk we want to wash off of our hands, whether it be dirt or germs, adheres to us thanks to the oils on our skin. Destroying the oil with a solvent like alcohol or kerosene will thus remove the associated germs.
However, although soaps used in hospitals are often strong, alcohol based versions, alcohol and kerosene are themselves toxic to varying degrees and thus not ideal for frequent in-home use. Imagine smelling like kerosene all day? Luckily, we have soap.
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.