The Truth About Hand Sanitizer
By Emi Yasuda
While it may make your whole lunch taste like “Wild Mango Mojito,” thousands of Americans still swear by hand sanitizer as an on-the-go essential. But due to inconclusive research, the verdict is still out on whether or not hand sanitizer and other antibacterial products are truly beneficial.
While dozens of questions remain unanswered, a few things are for certain. “Alcohol-based hand sanitizers are,” according to Mercy Medical Center’s Dr. Aaron E. Glatt, “a useful and important method to prevent most bacterial and viral infections.” They quickly reduce the number of microbes on your hands with 95% effectiveness in concentrations of alcohol greater than 60%.
But despite the large percentage of bacterium hand sanitizers eliminate, plain soap and water remains the superior alternative. Many discount chains carry inferior antiseptics, with 40% or lower concentrations of alcohol, facilitating bacterial growth instead of eliminating it.
For hand sanitizer that does work, an extra layer of defense is added, but not all viruses and bacteria can be killed by hand sanitizer. A study of over 1000 individuals conducted by the University of Virginia found that rates of rhinovirus infection are not significantly reduced by hand sanitizer use. Half of participants were controls, while the other half used hand sanitizer every three hours. At the end of the study, sanitizer users had 42 rhinovirus infections, and 12 flu cases per 100 subjects, while the control group had 51 rhinovirus infections and 15 flu cases per 100 subjects. This marginal difference provides little conclusive evidence that hand sanitizer truly reduces illness rates. Hand sanitizer is not only has little effect on rhinovirus, but also ineffective at killing norovirus, and C. Difficile, which takes 14,000 American lives each year.
So are these just rare exceptions to the common promise “Kills 99.9% of bacteria”? In a study of eighth grade students in Hamilton, Ontario, only 46%-60% of microbes on students hands were eliminated by sanitizers with the 99.9% promise. Why such a gap? Manufacturers do not need to kill 99.9% of all types of microbes nor disclose what microbes they exterminate to be able to give consumers a 99.9% promise. Thus, sanitizers can claim to be 99.9% effective, even when the sample of bacterium they were tested against represents only a fragment of infectious bacterium. While the microbes that remain are not necessarily more dangerous than those that were eliminated, doctors concur that a higher number of germs on your hands increases risk of infection.