Washington State University
Environmental Health & Safety Factsheet – Handwashing & Disinfection

Hand Washing & Disinfection:

Reducing the Spread of Infection


Why Wash?

According to the US Centers for Disease Control and Prevention (CDC), hand washing is one of the most important means of preventing the spread of disease. Washing your hands correctly greatly reduces the chances of spreading germs. Disease-causing germs can enter your body when touch your eyes, nose, mouth, or open wounds with your unwashed hands.

When to Wash

Hands should be washed whenever they become contaminated, such as after:

  • coughing, sneezing
  • using the restroom
  • changing diapers
  • handling garbage
  • handling uncooked foods
  • touching contaminated surfaces
  • touching animals and pets
  • caring for a sick person.

Hands should also be washed before:

  • preparing or eating food
  • smoking
  • treating a cut or wound or tending to someone who is sick.

How to Wash

How you wash your hands is as important as when you wash. Hands should be washed for at least 20 seconds using warm running water, lots of soap, and rubbing hands together vigorously. Dry your hands with clean disposable paper towels (do not use cloth towels).

Since hand washing is the most effective means of reducing the spread of germs, wash your hands thoroughly several times throughout the day.

Hand wipes and gel sanitizers can also be used, but they are not a substitute for handwashing. They are effective between hand washings when soap and water are not available as long as they contain at least 60% alcohol.

Getting Assistance

For questions about hand washing, disinfectants, or the prevention of colds, flu, and other illnesses, contact EH&S, your local health department, or the CDC.

Disinfecting Surfaces

In addition to good hand washing and personal hygiene practices, hand contact surfaces should also be disinfected periodically or whenever they become contaminated due to coughing, sneezing, dirty hands, etc.

Surfaces that should be disinfected include, but are not limited to: telephones, computer keyboards and mice, door knobs, drinking fountains, sink faucet handles, paper towel dispensers, and tables and desk tops. Research has found that desk surfaces may have as much as 400 times more bacteria per square inch than toilets.

Effective disinfection includes the use of antimicrobial chemicals. Those effective against Hepatitis B also work against other viruses, including flu viruses. A 10% bleach water solution is also effective on most surfaces. The Environmental Protection Agency web site lists approved antimicrobial chemicals.

When disinfecting surfaces, it is important to:

  • Follow chemical label directions and read safety precautions.
  • Clean surfaces with soap and water or another type of cleaner to remove dirt and debris prior to disinfecting.
  • Apply disinfectant to the surface and let stand for at least a few minutes (follow the label) to allow it to work.
  • Use disinfecting wipes or specially designed products on electronics (keyboards, mice, telephones). Liquids, especially some common cleaners, are corrosive to electronic components and may damage the circuitry or rubber components.
  • Wipe the surfaces with disposable paper towels or towels that will be washed afterwards.
  • If wearing gloves, wash your hands immediately after removing them.

Other Ways to Prevent Infection

In addition to hand washing, the spread of cold and flu and other diseases can be minimized with other personal hygiene measures, including:

  • covering your mouth whenever coughing or sneezing. Try to avoid coughing or sneezing directly into your hands by using tissues, the crook of your elbow, etc. If your hands do become contaminated, wash them immediately
  • disposing of contaminated tissues immediately
  • avoiding touching your mouth, nose or eyes. If you do touch them, wash your hands immediately
  • avoiding close contact with other individuals
  • staying home if you are sick, rather than coming into work, going to the store, etc.