Can I Use Tap Water for Baby Formula? What the CDC and AAP Say

Yes, in most cases. The CDC says that most of the time it’s safe to prepare powdered infant formula with tap water, filtered or unfiltered, and the American Academy of Pediatrics (AAP) says you can use tap water for powdered or concentrated formula unless there is known contamination of your local water. The main exceptions: boil the water first for babies younger than 2 months, babies born prematurely, or babies with weakened immune systems; test a private well for nitrate before using it; and use only cold tap water to limit lead from pipes. Your pediatrician is the best person to confirm what’s right for your baby.

This guide summarizes what the CDC and AAP recommend. It isn’t a substitute for advice from your baby’s doctor.

The short version

Situation	What the CDC and AAP advise
Healthy full-term baby, public water	Tap water is fine (filtered or unfiltered)
Under 2 months, premature, or weakened immune system	Boil water, cool about 5 minutes, mix while still hot, cool before feeding
Boil water advisory or other emergency	Bottled water or properly boiled water
Water contaminated with chemicals	Bottled water or ready-to-feed formula (boiling doesn’t help)
Private well	Test at least yearly for coliform bacteria and nitrate
Well nitrate above 10 mg/L	Don’t use for formula; boiling doesn’t remove nitrate
Older home or possible lead pipes	Cold water only; run it first if it sat unused; consider testing
Unsure about your water	Ask your local health department and your pediatrician

When to boil water for formula

For most babies, boiling isn’t required when you’re on a safe public water supply.

For higher-risk babies, the CDC recommends boiling. That means babies younger than 2 months, babies born prematurely, and babies with weakened immune systems. The reason is not the water itself: the CDC explains that powdered formula is not sterile and can occasionally contain germs such as Cronobacter, and very hot water, around 158°F (70°C), is needed to kill them.

The CDC’s steps for these babies:

Boil the water, then wait about 5 minutes.
Mix the powder while the water is still very hot, so the heat can kill germs.
Cool the bottle to body temperature before feeding (for example, hold it under cool running water). Test a few drops on the inside of your wrist; it should feel warm, not hot.

The AAP gives the same guidance for the same groups of babies. Ready-to-feed liquid formula is made to be sterile, so it’s another option for higher-risk babies; ask your pediatrician.

Don’t over-boil. The AAP advises against boiling water for a long time when making formula, because excessive boiling can concentrate lead and other impurities as water evaporates.

During emergencies. If tap water isn’t safe because of a boil water advisory, the CDC says to use bottled water until local authorities say tap water is safe, or to boil water (a rolling boil for 1 minute, or 3 minutes above 6,500 feet) and let it cool to room temperature before mixing. The CDC is clear that water contaminated with harmful chemicals or toxins cannot be made safe by boiling, disinfecting or filtering. In those cases, use bottled water or ready-to-feed formula. See our guide to boil water advisories.

Fluoride and formula

Many public water systems add fluoride to help prevent tooth decay. For babies, the question is dental fluorosis, faint white marks on the teeth that can form when young children get more fluoride than needed while their teeth are developing.

What the agencies say:

AAP: It is best to primarily use safe tap water that is fluoridated and occasionally use some non-fluoridated bottled water.
CDC: Formula that must be mixed with water (powder or liquid concentrate) may increase the chance of dental fluorosis if it’s a child’s main food and the water is fluoridated. Parents can use low-fluoride bottled water some of the time to lessen this risk.
Which bottled water is low-fluoride? The CDC says bottled water labeled de-ionized, purified, demineralized or distilled contains no or only trace amounts of fluoride, unless fluoride is listed as an added ingredient.

The CDC notes that fluorosis only develops while teeth are forming under the gums, up to about age 8. Fluoride in drinking water is the subject of active scientific and policy debate, which we cover in fluoride in tap water: what the science says. If you have questions about your baby’s fluoride intake, including whether your area’s water is fluoridated, ask your pediatrician or dentist. Your utility’s water quality report lists its fluoride level.

Private wells and nitrate

If your home uses a private well, nobody is testing it but you, and that matters more with a baby in the house.

Nitrate is the main concern. Nitrate comes from sources such as fertilizer runoff, septic systems and natural deposits. The EPA’s limit for public water is 10 mg/L (as nitrogen), and the EPA warns that infants below 6 months who drink water with nitrate above that level could become seriously ill.

The AAP recommends:

Test your well at least once a year for coliform bacteria and nitrate, and more often during pregnancy, when you have a new baby, after an unexplained illness, or after nearby contamination, repairs or flooding.
Don’t use well water above 10 mg/L nitrate for infant formula or food. Use purchased water, a public water supply, or water from a deeper well with low nitrate instead.
Don’t boil to fix nitrate. Boiling doesn’t remove it.

For more, see our posts on nitrate in tap water and well water testing.

Manganese is worth checking too, especially if your well water leaves black or brown stains. The EPA’s health advisory recommends that its 0.3 mg/L lifetime level be used for infants under 6 months even for short exposures, and the Minnesota Department of Health recommends 100 micrograms per liter (0.1 mg/L) or less for water given to infants or used in formula.

Lead: use cold water and run the tap

Lead usually gets into tap water from a home’s pipes, solder and fixtures, not from the utility. Babies are especially vulnerable to lead. The AAP’s guidance for families:

Never use water from the hot tap to make formula. Lead is likely to be highest in hot water. Heat cold water on the stove or in a kettle instead.
Run the cold tap first if it hasn’t been used for more than 6 hours: let it run 15 to 30 seconds before using it for drinking, cooking or preparing formula.
Test if you’re unsure. Lead can’t be seen, tasted or smelled. Ask your water provider about testing first.
Use a certified filter if you have lead concerns. Not all filters reduce lead; look for one certified by an independent organization to reduce lead, such as NSF/ANSI 53 with a lead claim.

The AAP also recommends that all children be screened for lead exposure at ages 1 and 2. Our guides to lead in tap water and finding out if you have a lead pipe explain the next steps.

Is filtered water OK?

Yes. The CDC says water for formula can be filtered or unfiltered. If you use a filter, replace it on the manufacturer’s schedule.

One caution: many filters remove chlorine, which also removes some protection against germs in water that sits. In a June 2026 report, the CDC described a 10-month-old with a weakened immune system who got Legionnaires’ disease, likely from a formula-mixing machine whose reservoir held warm water and hadn’t been fully drained in over a month. The machine was filled from a tap with an under-sink filter that removed chlorine, which the authors suggested may have contributed. If you use a formula machine, follow its cleaning instructions carefully, and ask your pediatrician about the safest approach if your baby has a weakened immune system. See our post on Legionella in home plumbing.

Mixing and storing formula safely

From the CDC:

Wash your hands and clean and sanitize bottles and your work area.
Measure the water first, then add the powder, using the exact amounts on the container. Too much or too little water can affect your baby’s nutrition or hydration. Never water down formula to stretch it.
Don’t microwave bottles if you warm them.
Use prepared formula within 2 hours of preparing it and within 1 hour of when feeding starts. If you won’t use it within 2 hours, refrigerate it and use it within 24 hours. Throw out any leftovers after a feeding.

The AAP adds that babies in their first 6 months don’t need extra water or other liquids beyond breast milk or formula unless a pediatrician advises otherwise.

How to check your water

Public water: Read your utility’s annual water quality report for lead, nitrate and fluoride results (how to read it), and look up your utility’s EPA record.
Private well: Test with a state-certified lab before your baby arrives, and at least yearly after that.
Not sure? The CDC suggests contacting your local health department, and your pediatrician can help you weigh the options for your baby.