Formula safety at home (1395)

How should I store formula?

• To travel with mixed or opened ready-to-feed formula, pack it in ice to keep it cold. 
• Mixed formulas can be kept in the refrigerator for 24 hours.  Label them with the date and time they are mixed.
• Once ready-to-feed formula or formula made from concentrated formula is opened:
  – Follow storage directions on side of the can of formula.
  – Cover leftover formula with a cap, plastic wrap, or aluminum foil.
  – Label with the date and time. 
  – Store it in the refrigerator. 
  – Use within 48 hours.  Throw away any that is left. 
• Cans of powdered formula should be stored in a cool, dry place. Once opened, cover the can with the overlap and use it within 30 days. Label the top of the can with the date you opened it.
• If an infant drinks from a bottle but does not finish it in an hour, throw it away.  Do not save the rest for later. It can spoil and make your baby sick. 
• If a child drinks formula from the bottle or can, by mouth or straw, and does not finish it in an hour, throw it out. It can spoil and make your child sick.
• When using a tube feeding bag:
  – Do not let open ready-to-feed formula hang at room temperature for more than 4 hours.  It can spoil. Use ice packs to keep the formula cold.  It can hang with ice for up to 8 hours.
  – Do not let mixed formulas hang at room temperature for more than 4 hours. Use ice packs to keep the formula cold.  It can hang with ice for up to 8 hours.  
• If you are using human milk, ask your nurse for human milk information.

How should I mix formula?

• Scoop sizes vary, so only measure powder with the scoop that came with the product.
• Prepare formula using the directions on the can. Mixing instructions may be different between products. Look closely to see how the formula should be measured. 
• The can may say things like: “scoops are to be leveled and unpacked” or “measure with a packed, leveled scoop”. If you have been given a special recipe from your provider, you still need to note if the scoop should be a leveled packed or unpacked.  
• If you have questions about mixing, contact the dietitian for more information.
• Shake ready-to feed formula and concentrated formulas before pouring into a bottle. This will mix any mineral sediment that settled during storage.

Do I need to warm formula?

• Formula does not need to be warmed. If you want to warm it, put the bottle of formula in a cup or pan of warm water for 2 to 3 minutes. You could also run the bottle with formula under hot tap water. Shake a few drops on your wrist to test the temperature of formula before giving to baby.
• Never heat formula in the microwave. You and your baby could get burned. 

What kind of water do I need to use to mix formula?

• Water used to mix infant formula should come from a safe source.  If you are concerned with the safety of your home water, contact your local health department about water testing.  
• If your tap water is safe, you can use room temperature tap water to mix your baby’s powdered formula.  
• If your tap water is not safe, use bottled water or bring cold tap water to a boil for one minute.  Boiling it longer can make the minerals in the water too strong.  It can also affect nutrients, such as Vitamin C.  Let it cool to room temperature before mixing the formula. This will keep it from clumping.  Use boiled water within 30 minutes.

Note: Bottled water does not always mean it is sterile.  

How to keep things clean and sanitary 

• Wash hands before making formula.
• Clean the area you will use to make the formula.
• Wash reusable bottles, caps and nipples in hot, soapy water or in the dishwasher before each use.
  - Most of the time, bottles and nipples do not need to be boiled. If they are washed in hot soapy water and rinsed them thoroughly, or run through the dishwasher they are clean enough.
• Wash and dry the top of the formula container before opening it.
• Refrigerate formula immediately after it is made.

Helpful information

If you are using powdered formula, go to https://childrenswi.org/health-information/breastfeeding-and-formula to find a video showing how to mix formula or add powder to human milk.