Do You Need an Antibacterial Cleaner?
Classified by law as pesticides, antibacterial cleaners are registered with the Environmental Protection Agency (EPA), which requires substantial proof of any germ-killing claims. Those claims are very specific and limited. In fact, some (including two cleaners in the lineup for our testing of all-purpose cleaners) don’t even claim to kill E. coli, one of the most commonly feared food-borne bacteria. It’s worth noting that the products’ germ-killing ingredients aren’t so good for humans or the kitchen, either: Labels include warnings about fumes and contact with skin or eyes, the importance of rinsing food-contact surfaces after use, and potential damage to common materials.
To see if you really need antibacterial sprays to kill germs, we sent one antibacterial spray, Lysol, and the four nonantibacterial sprays in our lineup to an independent laboratory. We also sent a bottle of ordinary white vinegar. The lab inoculated glass slides with measured quantities of E. coli or salmonella and then sprayed them with each of the cleaning products as well as with the undiluted vinegar. After 30 seconds (a time frame specified for sanitizing on the Lysol label), the lab counted the remaining microorganisms without wiping or rinsing (so that any reduction in bacteria would result from the cleaning product alone). This test was repeated a second time and the results were averaged. While we wouldn’t want to stake a brand’s reputation on the results of just two tests, they provided an interesting snapshot.
The surprise: All the cleaners reduced both types of bacteria by more than 99 percent, with the best performers (including Lysol) knocking out more than 99.9 percent of the germs and the “worst” performers coming in closer to 99.8 percent—a reduction that still sounded pretty good to us. But was it?
“[99.8 percent] is a good reduction but not enough to really do the job,” said product-formulation consultant Jim Hammer. He noted that the EPA usually requires at least a 99.9 percent reduction. Our winning cleaner, Method All-Purpose Natural Surface Cleaner, eliminated 99.9 percent of the salmonella and 99.8 percent of the E. coli. (Vinegar killed 99.9 percent of both types of bacteria. Too bad it left behind a streaky residue and a pungent smell.)
Why would cleaners without antibacterial agents kill germs? Their surfactants (compounds that break into the surface of liquids) disrupt the organism’s cell wall, creating a bactericidal effect—basically, they make the bacteria explode and die. “It’s not as strong as a quaternary ammonium compound [the predominant cleaning and germ-killing agents used in antibacterial sprays], but it does kill off some of the bacteria,” Hammer explained.
That said, even antibacterial sprays don’t work as advertised unless you follow label instructions to the letter, including, as a few products recommend, precleaning, spraying, waiting 10 minutes, wiping thoroughly, and rinsing with water. Essentially, if you choose an antibacterial spray and don’t use it correctly, it’s not doing the work you expect. Alternatively, if you choose a spray with no antibacterial claims, it’s still doing some germ killing. We’ll leave the final choice to you.