The alcohol in hand sanitisers may not have the 10–15 seconds exposure time required to denature proteins and lyse cells in too low quantities (0.3 ml) or concentrations (below 60%). In environments with high lipids or protein waste (such as food processing), the use of alcohol hand rubs alone may not be sufficient to ensure proper hand hygiene.

For health care settings like hospitals and clinics, optimum alcohol concentration to kill bacteria is 70% to 95%.

Alcohol rub sanitisers kill most bacteria, and fungi, and stop some viruses. Alcohol rub sanitisers containing at least 70% alcohol (mainly ethyl alcohol) kill 99.9% of the bacteria on hands 30 seconds after application and 99.99% to 99.999% in one minute.