Is It Safe to Drink Hot Tap Water? Why EPA and CDC Say Use Cold

No, you shouldn’t drink or cook with water from the hot tap. EPA says to “use only cold water for drinking, cooking and making baby formula,” and the CDC warns that water coming out of the tap warm or hot “can have higher levels of lead.” Hot water also spends time sitting in your water heater, where sediment collects and the water’s chemistry changes. If you need hot water for tea, pasta or a bottle, start with cold tap water and heat it on the stove, in a kettle or in the microwave.

Using hot tap water now and then for washing up is normal. The advice is specifically about water you swallow. Here’s why, and what to do instead.

Reason 1: Hot water can pick up more lead

Lead rarely comes from your utility’s treatment plant. It comes from your home’s plumbing. The CDC explains that most lead in household water comes from pipes, solder and fixtures inside the home, when the metal corrodes and dissolves into the water.

Temperature affects how fast that happens. EPA lists water temperature among the factors that influence how much lead gets into tap water, and the CDC says warm or hot tap water can carry more of it. That’s why both agencies draw the same line: cold for anything you drink or cook with.

This matters most if your home has any of these:

A lead service line (the pipe connecting your home to the water main)
Lead solder on copper pipes, common in homes built before the 1986 federal ban
Older brass faucets and valves

You can’t see, smell or taste lead. If you don’t know what your pipes are made of, our guide on how to find out if you have a lead pipe walks through the steps, and lead in tap water: how to test and protect covers testing.

Reason 2: Boiling doesn’t remove lead

A common assumption is that heating water cleans it. For germs, boiling works. For lead, it doesn’t.

Both EPA and the CDC state plainly that boiling water does not remove or reduce lead. So drawing hot water from the tap and then boiling it doesn’t fix the problem. You’d be heating water that may have already picked up extra lead on its way out of the pipes.

During a boil water advisory, the same rule holds: start with cold tap water, then boil it. Our boil water advisory guide covers the full process.

Reason 3: Your water heater is a storage tank, not a treatment system

A tank water heater stores water until you use it. A few things happen in there:

Sediment builds up. Minerals and rust settle at the bottom of the tank over time. EPA’s WaterSense program recommends flushing a water heater once a year to reduce sediment, and EPA notes that many manufacturers recommend flushing yearly, after plumbing work, or when the water is discolored.
The water’s chemistry changes. An EPA study of a full-scale home plumbing system found that hot water from tank and tankless heaters differed from the incoming supply in free chlorine levels, disinfection byproducts and other measures, and that the type of heater influenced both chemical and microbial water quality.
Discoloration. If only your hot water is rusty, brown or full of grit, the source is almost always the heater, not your utility. See the hot-water section of our guide to cloudy, brown or discolored tap water.

None of this means your shower water is unsafe. It means the water heater isn’t designed to deliver drinking water, and there’s no reason to drink from it when cold water is right there.

What about Legionella?

Legionella is the bacteria that causes Legionnaires’ disease, a serious type of pneumonia. It’s connected to hot water systems because of temperature. EPA says Legionella grows best between 80°F and 120°F, a range that a water heater set on the low side, or warm water sitting in pipes, can fall into.

The main risk isn’t drinking. EPA explains that people are usually exposed by breathing in small droplets or mist that contain the bacteria, such as from a shower. Swallowing water is a much less common route, and it causes illness mainly when water accidentally goes down into the lungs.

Water heater settings involve a trade-off:

EPA says setting the heater at or above 140°F can often keep temperatures high enough to prevent Legionella growth.
EPA also warns that water above 117°F at the faucet or shower can scald.
Thermostatic mixing valves blend hot and cold water near the outlet so the tank can stay hot while the tap stays safe.

Our Legionella in home plumbing guide covers who’s at higher risk and how to set up a water heater safely.

Baby formula: always start with cold water

Infants are the group where this matters most. The CDC notes that babies who drink formula made with lead-contaminated tap water may be at higher risk of exposure, because they consume a lot of water relative to their size.

For formula, use cold tap water (or another water source your pediatrician recommends) and warm it separately. Never use water straight from the hot tap. Our guide to tap water for baby formula covers how to choose and prepare the water.

What to do instead

A few simple habits cover almost every situation:

Use the cold tap for anything you’ll eat or drink. That includes coffee, tea, soup, rice, pasta, oatmeal and formula.
Heat cold water on the stove, in a kettle or in the microwave.
Flush pipes that have sat unused. If water hasn’t run for several hours, such as first thing in the morning, EPA recommends running the tap (or showering, doing laundry or running the dishwasher) before drinking. Ask your utility how long to flush if you have a lead service line.
Don’t run hot water through a filter. EPA’s lead guidance says not to run hot water through a point-of-use filter. Check your filter’s instructions too.
Use a lead-certified filter if you have lead sources. The CDC recommends a point-of-use filter certified to NSF/ANSI 53 for lead removal and NSF/ANSI 42 for particulate removal. Check the certifier’s listing for the exact model.
Maintain the water heater. Flush it according to the manufacturer’s instructions, or have a plumber do it. The water inside is hot enough to burn.

Does this apply to newer homes?

The risk is lower in homes built after 1986 with no lead service line, but EPA and CDC advice doesn’t make exceptions. Brass fixtures and repairs can still contain some lead, and the water heater issues apply to every home. Since heating cold water costs almost nothing extra, the simplest rule is to follow the guidance everywhere.

To see whether your utility has exceeded EPA’s lead action level recently, search your water system.

Bottom line

Hot tap water isn’t meant for drinking. It can carry more lead from your pipes, boiling won’t take that lead out, and the water has been sitting in a tank where sediment collects. Use cold water for drinking, cooking and baby formula, heat it yourself, and keep your water heater maintained.