The importance of good hand washing to prevent the spread of infection is widely accepted by scientists and the public. However, hand drying receives much less attention.

Some potentially harmful microbes remain on the hands after washing, and these are more easily spread if hands are not dried adequately. 

Proper hand drying completes the hand washing process by reducing the risk of spread of microbes.

Generally available hand drying methods in public washrooms are based on either water absorption (single use towels – paper or textile), water evaporation or water dispersal (warm air or jet air dryers).

Warm air dryers are usually slower than other methods at drying the hands.

There is scientific evidence that hand drying with single use towels rather than warm air or jet air dryers leads to lower numbers of microbes on hands and in the washroom (both in the air and on surfaces).

Jet air dryers are particularly likely to blow bacteria and viruses off the hands and around the washroom. Potentially harmful microbes could contaminate the user, other persons, the air we breathe and surfaces we touch, both in and outside the washroom.

Microbes from poorly washed hands may persist in the air for at least 15 minutes after the use of these jet air dryers.

The public and decision makers should be aware that some hand drying methods increase the risk of contaminating the hands, other individuals, the washroom surfaces, the air and areas outside the washroom.