<P> The evidence for hand hygiene in school generally is of poor quality . </P> <P> Alcohol - based hand sanitizer is preferable to hand washing with soap and water in most situations in the healthcare setting . It is generally more effective at killing microorganisms and better tolerated than soap and water . Hand washing should still be carried out if contamination can be seen or following the use of the toilet . </P> <P> Hand sanitizer that contains at least 60 percent alcohol or contains a "persistent antiseptic" should be used . Alcohol rubs kill many different kinds of bacteria, including antibiotic resistant bacteria and TB bacteria . 90% alcohol rubs are highly flammable, but kill many kinds of viruses, including enveloped viruses such as the flu virus, the common cold virus, and HIV, though is notably ineffective against the rabies virus . </P> <P> 90% alcohol rubs are more effective against viruses than most other form of hand washing . Isopropyl alcohol will kill 99.99 percent or more of all non-spore forming bacteria in less than 30 seconds, both in the laboratory and on human skin . </P>

What is in hand sanitizer that kills bacteria