What Water Should I Use for Baby Formula?

Mixing infant formula and water for your baby’s meal may seem like a simple task, but when you start to consider the potential contaminants that might be lurking in your water, you may find yourself with some unexpected questions.

Since every family’s situation is unique, there is no single answer that works every time for every family. However, the good news is that there are many reliable guidelines that you apply to your individual needs.

Smiling toddler holding a bottle full of formula

Let’s take a look at some of the questions you may have about the different kinds of water that are commonly available and how you can determine which one you should use for your baby’s formula.

How to Safely Prepare Formula with Water

Can I Use Tap Water?

Not all tap water is the same, so your individual situation is the best guide for whether you should use water straight from the tap or seek out an alternative.

Here are a few issues to take into consideration.

Municipal water

Municipal drinking water has to meet government standards for certain amounts of chemicals, so using tap water should be safe for healthy children. Ask your child’s health care provider for their recommendation of whether you can use your tap water.

Your local water department monitors the quality and safety of municipal water continuously, so be alert for and follow any contamination notices. You can also contact your water department directly if you have any questions.

Well water

Since it doesn’t have any mandatory regulations, working with well water can be a little more tricky. Testing a sample is the only way to know exactly what is in your well water, so make sure to have your well tested properly before you start to feed your baby bottles made with tap water. Additionally, have your well tested every year.


Regardless of whether you have municipal or well water, heavy metals like lead could get into your water from your home’s plumbing pipes. The United States government passed a law in 1986 mandating lead-free pipes, but lead could still be leaching into your water if your home was built before that year.

Since hot water can draw more lead out of your piping, always use cold tap water to make your child’s formula. Before you fill your bottle, let the cold tap run for about 15 to 20 seconds to let any standing water flush out.


If you want to avoid the excess plastic or the cost of buying bottled water but feel uneasy about using water straight from your tap, you may want to look into a home filtration system. You can choose between a pitcher, faucet-mounted or whole house filter.

  • Pitcher filters can do a good job of removing contaminants, but not all brands function to the same degree. Make sure that the product you’re interested in effectively filters out the specific elements you’re concerned about.

    Pitchers are typically reasonably priced, and their small size makes them easy to use and store. However, you’ll need to replace the filter from time to time, so factor that into your total cost per year.

  • Faucet-mounted filters attach to one sink in your home and filter the water as it comes from the faucet. As with pitcher filters, some faucet filters are more effective than others. Be sure to thoroughly read the description to find out what type of filtration system each product uses, and which contaminants the filter effectively removes.

    The cost can range a bit depending on which product you choose, and you’ll also need to replace the filters periodically.

  • Whole house filters are the most expensive option. These products filter all the water that flows through your house, including the bathroom and laundry water.

    These products typically use reverse-osmosis or distillation processes to purify your tap water. Aside from the initial purchase costs, you’ll also need to factor maintenance into the overall cost.

Do I Need to Boil Water?

There are conflicting opinions on mandatory boiling, especially for municipal water sources.

The American Academy of Pediatrics states that as long as your local water qualifies as a clean source, boiling isn’t always necessary. On the other hand, if you have any concerns about your water quality, boiling is a good idea.

Your child’s health care provider can also provide you with their opinion of whether boiling is necessary, and many parents choose to do it for an extra layer of protection.

Since there is no way for you to know if you have bacteria in your well, you need to boil water for every bottle if you have well water.

If your circumstances call for boiling or you prefer to do it, use a clean pot to bring the water to a rolling boil for one minute. Let the water cool for no longer than 30 minutes, then use it to prepare a bottle.

Keep in mind that boiling will kill most bacteria and viruses, but it will not remove heavy metals or other contaminants. While boiling your water for longer than one minute may seem like it would add additional protection, you run the risk of boiling off too many water molecules and ending up with a higher concentration of contaminants.

What’s the Deal with Fluoride?

Fluoride is a mineral that is present in your teeth and bones, and it also occurs naturally soil, water, plants, rocks and the air. In small amounts, fluoride’s protective, remineralizing effect can help your teeth stay healthy and strong.

While young children can benefit from appropriate amounts of fluoride, there is also the danger that their little bodies could get too much. Exposure to high levels of fluoride in infancy can cause the permanent teeth still developing within your child’s gums to have thin, white lines known as dental fluorosis. Although this condition isn’t dangerous, it is permanent and can be noticeable.

Most cities in the United States fluoridate municipal water, and many brands of concentrated or powdered formula also contain fluoride. If formula makes up the majority of your baby’s meals, use filtered or bottled water that does not contain fluoride, or alternate using fluoridated water with a non-fluoridated source.

Is Bottled Water an Option?

Bottled water is a good choice to prepare your child’s formula if you don’t have access to safe tap or home-filtered water.

Certain brands have different levels of fluoride, so make sure to pay attention to the kind of water you buy. Demineralized, purified, reverse osmosis or de-ionized waters all have low levels of fluoride and some other potential contaminants.

However, cost, availability and plastic usage are some of the drawbacks to using bottled water exclusively.

What About Using Distilled Water for Baby Formula?

Distilled water has gone through a specific purification process, so it’s a good option to use for your baby’s formula.

The distillation method consists of heating water to the boiling point to create steam, followed by a cooling phase that causes the steam to condense back into a liquid form. When the water turns into steam, most of the impurities get left behind, so the cooled, condensed water is free of most chemical and physical contaminants.

Other Things to Consider

Make Sure Your Formula Is Fresh

Due to the high fat content and delicate nutritional balance, your baby’s formula has a limited shelf life.

Make it a habit to check the expiration date on your current formula container frequently, and try not to have more than one container opened at once.

Clean Your Hands

You should always thoroughly wash your hands before working with any type of food, but making sure your hands are clean before preparing your baby’s bottle can be especially important. Young babies still have immature and inefficient immune systems, so reducing their exposure to germs in any way possible is always the best bet.

Prepare the Bottle

In most cases, washing your child’s bottles and nipples with hot, soapy water or in the dishwasher is sufficient to keep your child’s feeding supplies clean. However, talk to your child’s health care provider to determine if you need to boil your feeding items before every use, and follow their recommendations.

Measure Formula and Add Water

Follow the manufacturer’s instructions for how much formula to use in each bottle and how much water to add.

Even though formula can be expensive, don’t try to stretch it by adding more water than the instructions call for. Young babies need a specific amount of nutrients, fats and hydration at each meal, and altering the amount of water you use can throw all these levels dangerously off.

Warm the Bottle

While it’s not absolutely necessary to heat a bottle before giving it to your child, most babies seem to greatly prefer drinking milk that’s roughly body temperature.

Electric bottle warmers can help make the warming task much easier and faster, and these appliances usually have a compact design that won’t take up your entire counter. Check out this list of our favorite bottle warmers to give you some ideas for shopping.

Safe Formula Storage

Prepared formula can be an ideal breeding ground for bacteria, so make sure to store your baby’s bottles carefully.

Freshly prepared formula. You can safely leave an uneaten bottle of formula at room temperature for two hours after preparation. If your child is not ready to start their bottle within that timeframe, throw the formula away and use a clean bottle to prepare a fresh meal.

Partially eaten bottles. After giving your child their bottle, make sure they finish it within one hour. Throw out any remaining formula after that timeframe, and prepare a fresh meal in a clean bottle if your child is still hungry.

In the refrigerator. As long as you haven’t given your child the bottle at all, you can refrigerate prepared formula for up to 24 hours.

You can store concentrated or ready-to-feed formula for up to 48 hours after opening the package, but make sure to cover the container tightly and record the time of opening.

Closed or shelf-stable packages. Make sure to rotate your formula containers whenever you buy a new one to help you avoid finding an expired package that somehow made its way to the back of the line.


Parents often find that the little things they may have never thought about before suddenly become large concerns when the health of their child is at stake. By taking the time to learn about safe and potentially unsafe water sources for your child’s formula, you have the information to take any actions that might be necessary and get yourself a little peace of mind in the process.