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    Preparing Infant Formula: Important Safety Information

    Updated at May 16th, 2023

    If your baby is formula fed, it is important that he or she is getting all the nutrients needed for healthy growth and development. Here is information from the American Academy of Pediatrics (AAP) about what parents and caregivers need to know about preparing and giving infant formula safely.

    1. Always prepare formula as directed by the manufacturer.

    The AAP wants to remind parents and caregivers not to dilute (add extra water to) formula. Always mix formula as directed by the manufacturer.

    Adding extra water to formula or feeding babies water in addition to human (breast) milk or formula

    • Can lead to a dangerous condition called water intoxication.
    • Reduces the amount of nutrients baby will receive at each feeding. This can slow growth and development.
    • Disturbs electrolyte balance, which can lead to seizures.

    If you’re using formula but are having trouble paying for it, check with your baby’s doctor, local health department, food pantry, or social service agency.

    NOTE: Healthy babies do not need extra water. breast milk, formula, or both provide all the fluids they need. However, with the introduction of solid foods, water can be added to your baby’s diet. also, a small amount of water may be needed in very hot weather. If you live in an area where water is fluoridated, drinking water will also help prevent future tooth decay. If you have any questions, ask your baby’s doctor.

    2. Mix formula with water from a safe source.

    Water used for mixing infant formula must be from a safe water source, as defined by your state or local health department. You can check the water quality by contacting your state or local health department or the Environmental Protection Agency Safe Drinking Water Hotline (1-800-426-4791).

    If you are concerned or are uncertain about the safety of your tap water, here are 2 options.

    • You may use bottled water. However, let your baby’s doctor know if you are only using bottled water. Other sources of fluoride, such as fluoridated water or fluoride drops or tablets, may be recommended.
    • You may use boiled water. First bring cold tap water to a rolling boil for 1 minute (no longer), and then cool the water to room temperature for no more than 30 minutes before it is used.

    3. Make sure the temperature of the formula is not too hot.

    Before you feed your baby warmed up formula, you should test it to make sure it is not too hot. The easiest way to test the temperature is to shake a few drops on the inside of your wrist. Here are 3 ways to warm up formula in a bottle.

    • Use a bottle warmer.
    • Hold the bottle under warm running tap water.
    • Place the bottle in a container of warm water for 5 to 10 minutes. 

    Never microwave formula. Microwaving can affect ingredients in formula and cause hot spots in the liquid that can burn your baby’s mouth.

    NOTE: If you prepare formula with room temperature water, it does not need to be warmed up.

    4. Prevent germs.

    Here are tips to help prevent the spread of germs.

    • Hands: Always wash your hands before handling baby bottles or feeding your baby.
    • Preparation area: Remember to keep areas where formula is prepared, such as countertops and sinks, clean.
    • Nipples: Make sure nipples are clean. Scrub them in hot, soapy water, and then rinse to get rid of all traces of soap. Some experts recommend boiling them for 5 minutes.
    • Bottles: Make sure bottles are clean. You don’t need to boil the bottles; you can put them, along with mixing cups and other equipment used to prepare formula, in a dishwasher that uses heated water and has a hot drying cycle. Or wash the bottles inside and out in hot, soapy water, and make sure to rinse off all the soap.

    Types of Formula


    General Instructionsa 

    Keep in Mind 

    Ready to feed 

    Premixed liquid. Do not add water. 

    Be sure to shake it before feeding to mix in any ­mineral contents that may have ­settled.  

    Liquid ­concentrate 

    Mix with an equal amount of water. 

    Be sure to shake well before mixing it with water to blend the ingredients. 


    Mix 1 level unpacked scoop with 2 ounces of water.  

    Be sure to shake the powder and water together well.

    Always use the scoop that comes with the container. The shape and size of scoops can vary between brands and even between products ­within the same brand.


    aAlways prepare formula as directed by the manufacturer.

    Regular Well-child Visits

    To make sure your baby is developing and growing well, it’s important that you remember to schedule his or her well-child visits (health supervision checkups). The AAP recommends regular well-child visits from birth to age 21 years.

    Here are the visits recommended during the first year after birth.

    • Before your newborn leaves the hospital
    • Within 3 to 5 days after birth and within 48 to 72 hours after leaving the hospital
    • By 1 month
    • 2 months
    • 4 months
    • 6 months
    • 9 months
    • 12 months

    NOTE: The AAP recommends breastfeeding as the sole source of nutrition for your baby for about 6 months. When you add solid foods to your baby’s diet, continue breastfeeding until at least 12 months. You can continue to breastfeed after 12 months if you and your baby desire.

    5. Know how long to store prepared formula.

    There are 3 types of formula. (See Types of Formula chart.) Here is information about storing formula after it has been prepared, opened, or fed to your baby.

    • All formulas should be thrown out within 1 hour after feeding to your baby.
    • Formula made with powder that has not been fed to your baby may be stored in the refrigerator for 24 hours.
    • An open container of ready-to-feed formula, con­centrated formula, or formula prepared from concentrated formula should be covered, refrigerated, and thrown out after 48 hours if not used.

    For more information, visit HealthyChildren.org.

    Listing of resources does not imply an endorsement by the American Academy of Pediatrics (AAP). The AAP is not responsible for the content of external resources. Information was current at the time of publication. The information contained in this publication should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.

    © 2018 American Academy of Pediatrics. All rights reserved.