Hand sanitizer is a liquid, gel or foam generally used to kill many viruses/bacteria/microorganisms on the hands. In most settings, hand washing with soap and water is generally preferred.
Alcohol-based hand sanitizers usually contain a combination of isopropyl alcohol, ethanol, or propanol. Non-alcohol-based hand sanitizers are also available; however, in occupational settings (such as hospitals) the alcohol versions are seen as preferable due to their superior effectiveness at eliminating bacteria.
Hand sanitizers are not effective against all types of pathogens. They do not effectively kill bacterial spores, and certain parasites and viruses are resistant to their use.
Hand sanitizers are less effective if they are applied to skin that is contaminated with certain non-harmful chemicals such as grease. They also cannot effectively remove many harmful chemicals, such as paint, pesticides, and chemical fertilizers such as phosphates.