Procedures for Heating Formula

The Department does NOT recommend the use of microwaves for heating FORMULA OR FOOD.
The Licensing Rules for family and group child care centers PROHIBIT the heating of breast milk in microwaves.


  • Breast milk and pre-made bottles supplied by parents must be labeled with the child’s name, dated and stored in the refrigerator.
  • Breast milk may be kept frozen if it is the way it was supplied by the parent.
  • Infant formula and food in the original packaging must be stored and used as indicated on the label.
  • It is recommended that only BPA-free plastic, plastic labeled #1, #2, #4 or #5, or glass bottles or containers be used.
  • Warmed infant food should be transferred to a dish prior to serving.
  • Bottles and infant food may be served cold from the refrigerator or at room temperature.
  • Neither bottles nor infant food are required to be warmed.
  • It is recommended that the unused breast milk be discarded after 48 hours if refrigerated or after three months if frozen.
  • Unused frozen breast milk which has been thawed in the refrigerator should be used within 24 hours.
  • It is recommended that thawed breast milk or formula that has been out of the refrigerator for more than 1 hour or a bottle (or cup) that has been fed to the child for a period that exceeds 1 hour from the beginning of the feeding be discarded.
  • Partially consumed bottles or cups of formula or milk may not be placed in the refrigerator for later consumption.
  • Freshly expressed breast milk (not frozen) that has not been served to a child may remain at room temperature for up to 8 hours.


It is recommended that frozen breast milk be thawed under lukewarm running water or in the refrigerator.

Infant formula or food that remains unconsumed after a feeding should be discarded.

If parents request that bottles or infant food be warmed prior to feeding, it is recommended that bottles or food con- tainers be placed under warm, running tap water or placed in a container of water that is no warmer than 120 F.

Bottles or containers of infant food should not be left in a pot of water for longer than 5 minutes.

If a slow-cooking device such as a crock pot is used for warming breast milk, infant formula or food, this slow cooking device should be kept out of children’s reach.

It is recommended that electrical cords attached to crock pots be secured out of the reach of children to prevent children from grabbing the cord and pulling the device down on him or herself.

A slow-cooking device used to warm breast milk, infant formula or food should be emptied, cleaned, sanitized and refilled with fresh water each day.

Warm only the amount of breast milk, infant formula or food that the child
is expected to eat or drink at that feed- ing.

Although it is not recommended, if a provider chooses to use a microwave to warm infant formula or food, the following procedures should be followed:

Prior to warming in a microwave, remember:

• Warm only refrigerated formula
• Always stand the bottle up
• Always leave the bottle top uncovered to allow heat to escape

Warming instructions for 1 bottle:

• 4oz bottles – warm at low power for no more than 30 seconds • 8oz bottles – warm at low power for no more than 45 seconds

Serving instructions:

• Always replace nipple assembly; invert 10 times (vigorous shaking is unnecessary)
• Formula should be cool to the touch; formula warm to the touch may be too hot to serve • Always test formula; place several drops on top of the hand (not the inside wrist)


  1. Playtex, Evenflo and Gerber unanimously recommend against microwaving formula in nursers with disposable plastic inserts. Hot spots in the milk may weaken the seams.
  2. Use of glass bottles may result in cracking or explosion and should be avoided.
  3. When formula is microwaved, heat accumulates in the top of the
    bottle. So shake well and test the temperature by shaking some of the liquid on top of your hand. If heated formula feels warm to the touch it is probably above body temperature and should not be used immediately.
  4. Bottles must be heated without a nipple or a cap and inverted prior to serving to avoid oral cavity and esophageal burns.
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