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How should you store your breast milk?

Breast milk can be safely stored in a shared refrigerator with other food and beverages. Under certain work conditions, or because of your personal preference, you might instead choose to store your milk in a personal cooler with ice packs.

The Centers for Disease Control and Prevention offers the following guidelines on the proper handling and storage of human milk:

Safely Preparing and Storing Expressed Breast Milk:

  • Be sure to wash your hands before expressing or handling breast milk.
  • When pumping milk, be sure to store it in clean containers, such as screw cap bottles, hard plastic cups with tight caps, or breast milk storage bags. Avoid using ordinary plastic storage bags or formula bottle bags, as these could easily leak or spill.
  • Clearly label the milk with the date it was expressed to facilitate using the oldest milk first. If delivering breast milk to a child care provider, also include the child's name and any other information required by the provider.
  • Do not add fresh milk to already frozen milk within a storage container. It is best not to mix the two.

Safely Thawing Breast Milk:

  • As time permits, thaw frozen breast milk by transferring it to the refrigerator for thawing or by swirling it in a bowl of warm water.
  • Avoid using a microwave oven to thaw or heat bottles of breast milk
    • Microwave ovens do not heat liquids evenly. Uneven heating could easily scald a baby or damage the milk
    • Bottles may explode if left in the microwave too long.
    • Excess heat can destroy the nutrient quality of the expressed milk.

Breast milk that has not been finished can be safely used at the next feeding as long as the child has not fed directly from the container it was stored in (ie. if your child care provider pours half of the thawed milk into a bottle, the half left in the original container can be used later on).

The Office on Women's Health offers the following guidelines on breast milk storage:

Guide to storing fresh breast milk for use with healthy full-term infants

Place Temperature How long
Things to know
Countertop, table Room temp (60-85°F)

Up to 3-4 hours is best.

Up to 6-8 hours is okay for very clean expressed milk.

Containers should be covered and kept as cool as possible; covering the container with a clean cool towel may keep milk cooler. Throw out any leftover milk within 1 to 2 hours after the baby is finished feeding.
Small cooler with ice pack 59°F 24 hours Keep ice packs in contact with milk containers at all times; limit opening cooler.
Refrigerator 39°F or colder

Up to 72 hours is best.

Up to 5-8 days is okay for very clean expressed milk.

Store milk in the back of the main body of the refrigerator.
Freezer 0°F or colder

Up to 6 months is best.

Up to 12 months is okay.

Store milk toward the back of the freezer where temperature is most constant. Milk stored at 0°F or colder is safe for longer durations, but the quality of the milk might not be as high.

Guide to storing thawed breast milk

Room temperature Refrigerator (39°F or colder) Any freezers

Up to 1-2 hours is best

Up to 3-4 hours is okay

24 hours Do not refreeze

Learn more about pumping and milk storage.

Breast milk storage and handling guidelines for child care providers.