Alcohol based hand sanitizers usually have about 60-95% of alcohol in their composition. Non-alcohol hand sanitizers rely on other chemicals, such as Benzalkonium Chloride, the most frequently used chemical in such hand sanitizers.
Alcohol based hand sanitizers are frequently seen as the most effective. They can quickly and effectively destroy or inactivate many pathogens that cause disease such as HIV, influenza virus, H1N1, SARS, MERS, and other viruses and bacteria. The alcohol contained in these is usually ethanol (ethyl alcohol), isopropanol, and n-propanol. Ethanol appears to be the most effective against viruses while the other two are more effective against bacteria. Having an alcohol content of 60-95% is most effective.
While not much is known about non-alcohol based hand sanitizer, the CDC suggests that hand sanitizers without 60-95% alcohol might not work as well and might hinder the growth of germs rather than killing them.
The most effective way to use an alcohol based hand sanitizer is to put on enough to cover the surface of your hands and to rub until dry, which is around 25-30 seconds.