Tap water and ice

Tap water is safe to drink in many places, but not everywhere, and you cannot tell by looking at it. Where tap water may be unsafe, drink commercially sealed bottled water, or water you have boiled or treated yourself. Skip ice, and use safe water to brush your teeth.

Before you travel, check official travel health advice for your destination. If you are still unsure when you arrive, treat the tap as unsafe. The CDC advises not swallowing tap water, or even putting it in your mouth, unless you are reasonably sure it is safe.

Why tap water matters

Unsafe water is a major cause of illness worldwide. The World Health Organization (WHO) estimates that in 2022 at least 1.7 billion people used a drinking-water source contaminated with feces. Contaminated water can spread diarrhea, cholera, dysentery, typhoid, hepatitis A, and polio.

For travelers, the most common result is travelers’ diarrhea. Some people are more at risk of serious illness, including infants, young children, pregnant women, older adults, and people with a weakened immune system, according to the CDC.

How to find out if tap water is safe where you are going

• Check official travel health sites before you go. The CDC’s destination pages and the UK’s TravelHealthPro country pages give health advice for each country.
• Ask locally. Your hotel or host can usually tell you whether the tap water is treated for drinking.
• When in doubt, do not drink it. Use bottled, boiled, or treated water until you are confident.

The CDC also advises against using hot tap water for drinking or preparing food, because it can contain higher levels of metals such as copper and lead. Use cold water and heat it yourself.

Safe options when tap water is not safe

Option	What to know
Sealed bottled water	Buy commercially bottled water in an unopened, factory-sealed container. TravelHealthPro warns that fake bottled water exists, so check the seal.
Carbonated drinks	Sealed cans and bottles are generally safe. Wipe and dry the outside before drinking.
Hot drinks	Tea and coffee made with boiled water are generally safe if served steaming hot.
Boiling	Bring water to a rolling boil for one full minute. The Government of Canada calls it the best method to make water safe to drink.
Filters	Microfilters remove bacteria and parasites but not reliably viruses. Ultrafilters can also remove viruses.
Chemical tablets or drops	Chlorine works well against bacteria and viruses but poorly against Cryptosporidium. Chlorine dioxide works against all of these but can need several hours. Follow the instructions exactly.
UV light pens	Work against bacteria, viruses, and parasites, but only in clear water.

A few extra points from the CDC and TravelHealthPro:

• Cold or cloudy water makes chemical treatment less effective. The CDC advises using bottled water if tap water is cloudy or discolored.
• Iodine treatment is not suitable for pregnant travelers, people with unstable thyroid disease, or people allergic to iodine, and the CDC notes that WHO advises limiting its use to a few weeks.
• Store treated water in clean, covered containers so it does not get contaminated again.
• Plastic waste. The CDC notes that plastic bottles cause environmental problems. A reliable filter or boiling water can cut the number of bottles you buy.

Is ice safe?

Ice is only as safe as the water it was made from. The CDC advises avoiding ice in places with limited access to clean water, because it was likely made with tap water. Freezing does not make contaminated water safe, and alcohol does not help either: the CDC says alcohol does not kill germs in ice made from contaminated water.

Where tap water may be unsafe:

• Order drinks without ice.
• Avoid fountain drinks, which are likely made with tap water, and fresh juice made by someone else.
• Ice made from purified or disinfected water is fine, as the Government of Canada notes. If you cannot find out how the ice was made, skip it.

Brushing teeth, showers, and other everyday contact

Water can reach your mouth in ways you might not expect. Where tap water may be unsafe:

• Brush your teeth with bottled or disinfected water.
• Avoid swallowing water in the shower.
• Never rinse contact lenses with tap water.
• Do not use tap water for nasal rinsing unless it has been further disinfected.
• Avoid swallowing pool water, and do not swim if you have diarrhea.

Raw fruit, vegetables, and salads

Produce washed in unsafe tap water can carry the same germs as the water itself. The CDC advises avoiding salads and fresh sauces made from raw fruit or vegetables where water may be unsafe. Fruit is safer if you peel it yourself or wash it in bottled or disinfected water. Our guides on avoiding food poisoning when traveling and street food cover food choices in more detail.

Babies and infant formula

Babies are especially vulnerable to unsafe water. For formula-fed babies, the CDC advises parents to consider sterile, ready-to-feed liquid formula when traveling, because no powdered formula is sterile. If you use powdered formula for a baby under 3 months or with a weak immune system, prepare it with water boiled and cooled to no less than 70°C (158°F).

TravelHealthPro adds that bottled water is not generally recommended for making formula, because it may contain too much sodium or sulfate and is usually not sterile. Ask your pediatrician or a pharmacist for advice before you travel.

What if you drank unsafe water?

Do not panic, but watch for symptoms such as diarrhea, stomach cramps, nausea, or fever. The CDC says bacterial and viral infections usually start within a few hours to four days, while parasites usually take one to two weeks. If you get sick, drink plenty of safe fluids, ideally oral rehydration solution. Our guide to food poisoning while traveling explains when to see a doctor.