Hand Hygiene, Explained Without the Jargon
Hand Hygiene: what it is, why it matters, and what published guidance actually asks of you.
It is the cheapest infection-control measure there is, and the choice between soap and sanitizer matters more than people realize.
Key takeaways
- Handwashing duration: at least 20 seconds with soap and clean running water
- Hand sanitizer: at least 60 percent alcohol, when soap and water are not available
- Most useful single change: Use soap and water after any vomiting or diarrhea.
- Commonest mistake: Relying on hand sanitizer during a norovirus outbreak.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
The short answer
Removing germs from hands mechanically with soap and water, or chemically with alcohol-based sanitizer.
Where it fits
This is part of Immunity. The rest of this page works through the figures and then the practical side.
The numbers, in one place
| Measure | Figure |
|---|---|
| Handwashing duration | at least 20 seconds with soap and clean running water |
| Hand sanitizer | at least 60 percent alcohol, when soap and water are not available |
| Sanitizer against norovirus | does not work well; use soap and water |
| Key moments | before eating or preparing food, after using the toilet, after caring for someone sick |
| After norovirus | do not prepare food for others for at least 2 days after symptoms stop |
What that means in practice
In everyday terms:
- Use soap and water after any vomiting or diarrhea
- Wash for a full 20 seconds, including thumbs, between fingers and under nails
- Dry hands properly; wet hands transfer more germs
- Keep sanitizer for when soap and water are unavailable
What gets people into trouble
And the things that tend to go wrong:
- Relying on hand sanitizer during a norovirus outbreak
- Preparing food for others within 2 days of symptoms stopping
- Assuming antibacterial soap is needed; plain soap works
Related topics
- What the Guidance Really Says About Norovirus (Infectious Diseases)
- Food and Water Safety Abroad: Sorting the Evidence From the Noise (Travel Health)
- Dry Skin: Sorting the Evidence From the Noise (Skin Health)
- The Evidence on The Four Steps to Food Safety, Without the Hype (Food Safety)
Where to go next
- Hand Hygiene: Separating Myth From Guidance
- New to Hand Hygiene? Start Here
- Hand Hygiene — the reference entry
- Immunity: The Complete Guide
- The Evidence on Fever, Without the Hype
- Vitamin C: What the Evidence Actually Says
When to speak to a doctor
Contact your doctor for diarrhea lasting more than 2 days in an adult, vomiting that stops you keeping fluids down, blood in your stool, or signs of dehydration such as little or no urine, dizziness or extreme thirst. Get prompt advice for babies, older adults and people with weakened immune systems, who become dehydrated faster. Call 911 for confusion, fainting or severe dehydration.
Where this comes from
- CDC — When and How to Wash Your Hands
- CDC — Preventing Norovirus
- National Institute of Diabetes and Digestive and Kidney Diseases — Diarrhea
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.
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