Everyday soap does not kill bacteria. Rather, vigorous hand-washing with soap helps to release the dirt and oils that are on the surface of your skin, so that they can be rinsed away easily. Although soap and water eliminate some of the body’s good germs as well as the bad germs, regular hand cleaning improves the proportion of good germs on the hands.

Instant hand sanitizers, such as Purell, work when soap and water are not available. They contain alcohol, a natural antiseptic, which quickly kills germs, then evaporates without leaving any residue on the skin.

The CDC recommends the use of these products in hospitals, home, work and schools because they help to stop the spread of germs. Anti-bacterial soaps, such as Dial, contain chemicals that also kill germs.

It is estimated that failure to wash hands thoroughly with regular soap contributes to almost half of the 76 million cases of food-borne illness each year. The most severe cases occur in the very old, the very young, and those with other illnesses. The most commonly recognized infections are those caused by the bacteria campylobacter, salmonella and E. coli 0157:H7.