Hand sanitizers kill 99.99 percent of viruses and bacteria, but that other 0.01 percent can include some serious germs. Additionally, not all hand sanitizers are the same. Find out about why hand sanitizers are not all alike and learn about their effectiveness, benefits, limitations and dangers.
Not all hand sanitizers are created alike. Alcohol-based hand sanitizers kill more types of germs than most of the other forms on the market. Other active ingredients include triclosan and benzalkonium chloride, but bacteria can develop resistance to these ingredients.
In general, alcohol has more reliable disinfectant properties than other antibacterial ingredients. It kills germs by structurally destroying them rather than by poisoning them, a similar effect to that of hand washing.
Many hospitals and work environments have adopted alcohol-based hand sanitizer to fight the spread of methicillin-resistant staphylococcus aureus, better known to the public as MRSA, the staph infection that resists multiple antibiotics.
Alcohol-based sanitizers kill this bacterium more effectively than one former front line hand sanitizer, triclosan, an antibacterial chemical. Research in 2004 by Schmid and Kaplan, published in Antimicrobial Agents and Chemotherapy, shows that MRSA has developed resistance to triclosan just as it has to many antibiotics.
Norovirus, also known as the stomach flu virus, notoriously resists most common disinfectants, including most hand sanitizers. According to an August 2008 study in Applied & Environmental Microbiology, the average alcohol-based hand sanitizer has relatively little effect on this gastrointestinal scourge. In this study, the researchers developed a new formulation that had a stronger effect against norovirus. Hand sanitizers still do not replace hand washing when fighting the spread of this illness.
Alcohol-based hand sanitizer has its own potential hazards. Accidental poisoning can occur; keep the bottle away from the reach of unsupervised children. When signs indicate that a child may have ingested hand sanitizer, watch for sleepiness and upset stomach--signs of alcohol poisoning--and call a poison control center for advice. A Sept. 8, 2009 article in the Houston Chronicle reports many incidents but no deaths.
The high alcohol content also makes this type of sanitizer very flammable--keep it away from open flames and other fire hazard environments.
Hand sanitizer can also cause skin dryness, leading to broken skin, which exposes the body to the same contagions users are trying to prevent.
Although hand sanitizers have their dangers, ultimately they serve a useful purpose: The benefits outweigh the risks. While hand washing kills germs more effectively than any other sterilization method, busy professionals in health and education do not always have time to get to a sink. A reliable alcohol-based hand sanitizer can fill in the gaps, allowing better prevention of cold and flu transmission.
Do not use hand sanitizer as a primary means of disinfecting hands in food preparation. While it may be useful in health care and education settings, hand sanitizer will not penetrate grease, wetness or food residue. Because of this, and since it demonstrates less effectiveness against norovirus than against other microbes, even the best hand sanitizer should only be used as an adjunct to hand washing in all settings.