Question: I’ve always used Purell but just read about hand sanitizers that contain benzethonium chloride (BC), which are supposed to last longer. Which is more effective for everyday use?
Answer: Hand sanitizers with BC might last an hour or two longer, but they may take 10 minutes or more to dry before they can kill germs. Alcohol-based hand sanitizers such as Purell, which contains 62% ethanol, evaporate quickly, killing most microbes in seconds. BC sanitizers stay on your hands longer, but they take too long to kill germs and leave more live germs behind. Studies have not shown BC sanitizers to be as effective as those with alcohol, so the Centers for Disease Control and Prevention recommends hand sanitizers with at least 60% alcohol. However, a BC-based sanitizer will provide longer-lasting protection to cuts or other wounds that are covered by a bandage.