Safe storage of expressed breast milk

If you're expressing breast milk, it's important that you store it safely and correctly.

Below you will find important information about handling and storing breast milk.

Before expressing or handling breast milk

• Wash your hands well with soap and water. If soap and water are not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol
• Mothers can express breast milk by hand or with a manual or electric pump
• If using a pump, inspect the pump kit and tubing to make sure it is clean. Discard and replace moldy tubing immediately
• If using a shared pump, clean pump dials, power switch, and countertop with a disinfectant wipe.

Storing breast milk after expressing

• Use breast milk storage bags or clean, food containers to store expressed breast milk. Make sure the containers are made of glass or plastic and have tight fitting lid. (Avoid bottles with the recycle symbol number 7, which indicates that the container may be made of a BPA-containing plastic.)
• Never store breast milk in disposable bottle liners or plastic bags that are not intended for storing breast milk.

Freshly expressed or pumped milk can be stored:

• at room temperature (77°F or colder) for up to 4 hours
• in the refrigerator for up to 4 days
• in the freezer for about 6 months is best; up to 12 months is acceptable.

Storage tips

• Clearly label the breast milk with the date it was expressed.
• Do not store breast milk in the door of the refrigerator or freezer. This will help protect the breast milk from temperature changes from the door opening and closing.
• If you don’t think you will use freshly-expressed breast milk within 4 days, freeze it right away. This will help to protect the quality of the breast milk.

When freezing breast milk:

• Store small amounts to avoid wasting milk that might not be finished. Store in 2 to 4 ounces or the amount offered at one feeding.
• Leave about one inch of space at the top of the container because breast milk expands as it freezes.

If you deliver breast milk to a child care provider, clearly label the container with the child’s name. Talk to your child care provider about any other requirements for labeling and storing breast milk.

Breast milk can be stored in an insulated cooler with frozen ice packs for up to 24 hours when you are traveling.

At your destination, use the milk right away, store it in the refrigerator, or freeze it.

Safe thawing of breast milk

Always thaw the oldest breast milk first. Remember first in, first out. Over time, the quality of breast milk can decrease.

There are several ways to thaw your breast milk:

• In the refrigerator overnight.
• Set in a container of warm or lukewarm water.
• Under lukewarm running water.

Never thaw or heat breast milk in a microwave. Microwaving can destroy nutrients in breast milk and create hot spots, which can burn a baby’s mouth.

If you thaw breast milk in the refrigerator, use it within 24 hours. Start counting the 24 hours when the breast milk is completely thawed, not from the time when you took it out of the freezer.

Once breast milk is brought to room temperature or warmed, use it within 2 hours.

Never refreeze breast milk after it has thawed.

Feeding expressed breast milk

Breast milk doesn't need to be warmed. It can be served at room temperature or cold.

If you decide to warm the breast milk, here are some tips:

• Keep the container sealed.
• Place the sealed container into a bowl of warm water or hold it under warm, but not hot, running water for a few minutes.
• Test the milk’s temperature before feeding it to your baby by putting a few drops on your wrist.

Do not heat breast milk directly on the stove or in the microwave.

Swirl the breast milk to mix the fat, which may have separated.

If your baby did not finish the bottle, use the leftover milk within 2 hours after the baby is finished feeding.

After 2 hours, leftover breast milk should be discarded.

Human milk storage guidelines