To find clean drinking water while traveling, start by checking official travel health advice for your destination. Where the tap water isn't safe, drink sealed bottled water or hot drinks, skip the ice, and brush your teeth with safe water. If you can't buy water, boil it for one minute, or filter it and then disinfect it. This guide shows you how to check any country, which treatment method removes what, and how to keep a bottle filled on the go.
How to know if the tap water is safe in a foreign country
You can't tell by looking. Clear water can still carry germs, and cloudy water isn't always unsafe. Check these sources before you go:
- CDC Travelers' Health: pick your country on the CDC destinations page. Each page lists the vaccines and health risks for that place, including diseases you can catch from food and water.
- TravelHealthPro: the UK's National Travel Health Network and Centre has country pages and a food and water hygiene factsheet.
- Your government's travel advice: for example, Canada's travel advice pages have a Health section for each country.
- The local water company or city: many cities publish whether their tap water meets drinking standards. Search for the city name plus "water quality".
- Your hotel or host: ask if the tap water is drinkable and whether they have filtered water. Look for signs over the sink saying the water is not for drinking.
The answer can change within one country. A big city with treated water can be very different from a rural well, a campsite or a river. If you can't confirm the water is safe, treat it as unsafe.
What to drink when you can't trust the tap water
The CDC's food and drink advice for travelers boils down to a few rules:
- Sealed bottled water: buy it in unopened, factory-sealed bottles. Check the seal, because some vendors refill bottles with untreated water.
- Fizzy drinks: sodas and sparkling water in sealed bottles or cans are usually safe. The bubbles suggest the drink was sealed at the factory.
- Hot drinks: coffee and tea are fine if they are served steaming hot.
- Milk: pasteurized milk from a sealed bottle is usually safe.
Watch out for ice, juice and street drinks
- Ice: skip it where clean water is hard to find. It is often made with tap water, and the alcohol in a drink won't make the ice safe.
- Fresh juice: avoid juice squeezed by others. If you wash and peel the fruit yourself with safe water, it's fine.
- Street drinks: lemonades, agua frescas and smoothies are usually made with local water and ice. Go for sealed or hot drinks instead.
Brushing your teeth and showering
Brush your teeth with bottled or treated water, and keep your mouth closed in the shower. The CDC Yellow Book says unsafe tap water can make you sick through drinking, cooking, ice and brushing teeth.
Boiling, filters, tablets or UV: which water treatment works best?
If you can't buy sealed water, you can make water safe yourself. Here is what each method does, based on the CDC's guide to avoiding contaminated water during travel and the Yellow Book chapter on water disinfection.
Boiling: the most reliable option
Bring the water to a full rolling boil for 1 minute. Above 6,500 feet (about 2,000 m), boil it for 3 minutes. Boiling kills bacteria, viruses and parasites. Let it cool in a clean, covered container.
Portable filters: good against parasites and bacteria
Most portable filters are microfilters. They remove parasites such as Giardia and Cryptosporidium and most bacteria, but they don't reliably remove viruses like norovirus. Ultrafilters with much smaller pores can also remove viruses. Filters are handy when the water is cloudy, and they work well together with tablets.
Purification tablets and drops: light, but slow
- Chlorine or iodine tablets kill most bacteria and viruses, but they work poorly against Cryptosporidium. Don't use iodine if you're pregnant, have thyroid problems or an iodine allergy, and don't use it for more than a few weeks.
- Chlorine dioxide tablets also work against Cryptosporidium when you follow the instructions, but they can need hours of waiting time.
- Cold or cloudy water makes chemical treatment less effective.
UV purifiers: only for clear water
Battery-powered UV pens and bottles can disinfect small amounts of clear water. Particles in cloudy water can shield germs from the light, so filter or let cloudy water settle first.
So which one should you pack?
- City trips with shops nearby: sealed bottled water and a kettle for boiling are usually enough.
- Hiking, camping or rural travel: a filter plus chlorine dioxide tablets covers parasites, bacteria and viruses.
- Chemicals: no method here makes water with chemical pollution safe. If you suspect it, don't drink it.
Can you drink the water in Mexico?
Plan not to drink it straight from the tap. Canada's travel advice for Mexico tells you to drink water from a safe source and to follow food and water precautions. Stick to sealed bottled water, hot drinks and drinks without ice, and brush your teeth with bottled water. Some hotels provide bottled or filtered drinking water, so ask at check-in.
And yes, boiling tap water for 1 minute kills the germs. It won't remove chemical pollution, though, so where you have the choice, sealed bottled water is simpler. Going soon? Our guide to the best eSIM for Mexico covers staying connected there.
How to find water refills while you travel
Buying bottle after bottle gets expensive and creates a lot of plastic waste. A few habits help:
- Carry a reusable bottle. Fill it with safe water before you leave your hotel each morning.
- Ask where to refill. Many hotels, hostels and cafés have filtered water dispensers or large refill jugs.
- Use public fountains only where locals say they're drinkable. In some cities fountains are fed by treated tap water. Elsewhere, they may not be safe at all.
- Search your map app. Try "drinking water", "water refill" or "drinking fountain" to find spots near you.
- Bring a filter bottle for remote trips. Remember that most filters don't remove viruses.
Look it up on the spot
Most of these tips are easier with mobile data: checking official health advice, finding a shop or refill spot on a map, or translating "Is this water safe to drink?" for a waiter. A travel eSIM gives you data from the moment you land, without hunting for Wi-Fi. Our list of must-have travel apps has the maps and translation apps that help most.
If you're heading somewhere where you'll check the water a lot, these data-only eSIMs are a good place to start:
Mexico, Asia and India data plans · See all destinations
Stay hydrated without taking risks
- Drink before you're thirsty in hot places and on long days out, so you aren't tempted by water you can't trust.
- Plan your water for day trips and hikes. Fill up before you go and pack a backup treatment method.
- Pack oral rehydration salts. Canada's travel advice suggests them for travelers' diarrhea, the most common illness on trips.
If you still get sick, our guide to getting sick abroad explains what to do and what care can cost, and here's why travel insurance is worth having.
FAQ
What is the best water treatment for international travel?
Boiling for 1 minute is the most reliable method if you have a kettle or stove. On the move, a filter combined with chlorine dioxide tablets covers parasites, bacteria and viruses. UV works only on clear water.
Is bottled water always safe?
Not always. Buy it in factory-sealed bottles and check the seal. The CDC notes that in some places bottled water may be no better than tap water, so choose brands that locals and your hotel trust.
Can I brush my teeth with tap water abroad?
Where the tap water isn't safe to drink, use bottled or treated water for brushing your teeth too.
Is it safe to drink water from the hotel bathroom sink?
Only if the tap water in that place is safe to drink. Ask at reception, and look for a sign over the sink. Some hotels in places with unsafe tap water put bottled water in the room.
What are the dangers of drinking unsafe water?
According to the World Health Organization, contaminated drinking water can spread diarrhoea, cholera, dysentery, typhoid and polio. Ask a travel health clinic which vaccines you need before your trip.
Does boiling water remove all contaminants?
No. Boiling kills germs, but it doesn't remove chemicals, heavy metals or dirt. If water may be polluted with chemicals, don't drink it, even after boiling.
