Does Boiling Tap Water Make It Safe to Drink?
Boiling is the oldest water-safety trick there is — and for good reason. But it’s not a cure-all. Here’s exactly what boiling tap water fixes, what it doesn’t, and how to do it properly.
What boiling removes
Heat kills living things. A proper boil reliably destroys the biological contaminants that cause most water-borne illness:
- Bacteria — including E. coli, cholera, and salmonella
- Viruses — such as hepatitis A, norovirus, and rotavirus
- Parasites — like Giardia and Cryptosporidium
This is why a “boil-water notice” is issued after contamination or a main break: boiling makes microbiologically unsafe water safe to drink.
What boiling does NOT remove
Boiling does nothing to chemical or physical contaminants — and can make some slightly worse by concentrating them as water evaporates:
- Lead and other heavy metals
- Nitrates (from agricultural runoff)
- PFAS (“forever chemicals”), pesticides, and industrial solvents
- Chlorine by-products
If your concern is lead from old pipes or chemical contamination, boiling won’t help — use a filter certified to NSF/ANSI 53 for the specific contaminant, or bottled water.
How to boil tap water safely
- Bring water to a full, rolling boil.
- Keep it boiling for at least 1 minute (3 minutes above ~2,000 m / 6,500 ft, where water boils cooler).
- Let it cool on its own, then store it covered in a clean container.
- Cloudy water? Filter it through a clean cloth or let it settle first, then boil.
Should you boil your tap water?
For most people in countries with safe public water, no — it’s unnecessary. Boiling matters when you’re travelling somewhere with unsafe tap water, during a boil-water advisory, or if you rely on an untested private source. Not sure about your destination? Check its score first — search any country, US state, or French région — and see our disclaimer on what our scores do and don’t cover.
Frequently asked questions
How long should you boil tap water to make it safe?
Bring the water to a full, rolling boil and keep it there for at least one minute (three minutes at high altitude, above ~2,000 m / 6,500 ft). Then let it cool naturally — don’t add ice made from unsafe water.
Does boiling remove chlorine, lead, or chemicals from tap water?
No. Boiling kills microbes but does not remove chemical contaminants. In fact, boiling can slightly concentrate lead, nitrates, and other dissolved chemicals as water evaporates. Use a certified filter or bottled water for those.
Is it safe to drink boiled tap water every day?
If your only concern is microbes, yes — boiled and cooled tap water is safe to drink. If you have chemical contamination concerns, boiling alone isn’t enough; combine it with an appropriate filter.