Throughout my book Germ Proof Your Kids – the Complete Guide to Protecting (without Overprotecting) Your Family from Infections (ASM Press, Washington, D.C., 2008) you’ll note that I tout the germ-proofing abilities of bleach. Bleach is known to be the most effective disinfecting agent against both bacteria and viruses, the causes of most infections. As a household surface disinfectant for all solid surfaces in the kitchen, bathroom, playroom, child’s sick room, and laundry room, bleach-containing disinfectants have been shown to markedly reduce the numbers of potentially dangerous bacteria like E. coli, Salmonella, Campylobacter, Strep and Staph (including the resistant “superbugs”). Bleach disinfectants also work against the viruses that cause diarrheal illness, the viruses that cause colds and flu, and even the viruses that cause hepatitis and AIDS. In the laundry, bleach added to the usual wash cycles also dramatically improves germ-killing. For these reasons, bleach-containing disinfectants have also long been my preferred products for disinfecting schools and workplaces (see Chapter 9 in Germ Proof Your Kids – the Complete Guide to Protecting (without Overprotecting) Your Family from Infections).
But, although we have long known how effective bleach-containing disinfectants and laundry products are, it wasn’t until an elegant study published in the prestigious scientific journal Cell just last month (November 14, 2008) that we now understand how bleach actually works. One of the active ingredients of household bleach, hypochlorite, permanently unfolds and clumps the proteins of bacteria, killing those germs. You can picture this process as looking exactly like the effect of boiling a raw egg – the formerly fluid proteins of the egg permanently clump into a hard-boiled, solid egg. Although the new study only looked at bacteria, the impressive killing effect of bleach on viruses may also be due to the same unfolding and clumping process of virus proteins.
Another very cool aspect of the study by these investigators is that It turns out that our own immune systems also produce hypochlorite as part of our natural defenses against infection! That is, our bodies naturally produce hypochlorite (the active ingredient in household bleach) to kill invading germs.
So there you have it. We have effectively used bleach to disinfect our homes, schools, workplaces, and laundry for several decades now and, finally, we understand why it works so well. Live and learn!