Janice is going back to work after maternity leave. She’d like to express and store her breast milk for her baby, so her husband, mother, and child care provider can all feed the baby breast milk when she’s not there.

Like a lot of new moms, she has questions about how to make sure she’s storing breast milk so it’s safe for her little one to drink.

The CDC provides easy to understand guidance for expressing and storing breast milk here. You can find even more information there about these frequently asked questions:

Should breast milk go in the refrigerator? How long can we keep it? Is it OK to freeze?

The CDC provides these guidelines for storing freshly pumped breast milk:

• Up to 4 hours at room temperature (77 degrees or lower)
• Up to 4 days in the refrigerator (40 degrees or lower)
• Up to 12 months in the freezer, though 6 months or less is preferred

Try to freeze breast milk in small amounts of 2 to 4 ounces, so you only have to thaw what you can use.

Thawed breast milk should not be re-frozen. Always thaw and use the oldest breast milk first. One way to remember is first in, first out. If you don’t think you’ll use breast milk right away, instead of leaving it in the refrigerator, it’s best to freeze it right away.

What kind of container should I put breast milk in?

Storage bags made especially for breast milk are a good choice. You can also use clean food-grade containers made of plastic or glass that have tight-fitting lids.

DO NOT store breast milk in disposable bottle liners or plastic bags not made specifically for breast milk. These containers may have chemicals that can get into the breast milk.

Clearly label all containers with the date the breast milk was expressed.

Do I need to sterilize equipment or take other safety steps?

Breast milk can be expressed by hand, with a manual pump, or with an electric pump. Because germs can grow quickly in breast milk and the items you use to collect it, you should:

• Wash your hands well with soap and water before expressing or pumping.
• If soap and water are not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol.
• Thoroughly clean a breast pump immediately after using it, and inspect it carefully before using it again.
• Clean any brushes or basins you use to wash the breast pump.
• Keep the pumping area clean, wiping counters with disinfectant wipes.
• The CDC recommends you sanitize breast pump parts, wash basins, and brushes at least once daily.
• First, clean the breast pump thoroughly.
• Then, check the pump manufacturer’s instructions to see if parts can be steamed or boiled.
• Let parts air dry on a clean towel or paper towel but don’t pat them dry—because this can transfer germs back to the parts you just sanitized.

If you’re using a dishwasher with hot water and heat dry on sanitizing settings, you don’t need to also steam or boil.

What’s the best way to warm breast milk?

First, breast milk does not have to be warmed. You can serve it to an infant at room temperature or cold. If you’re thawing it or do want to warm it:

• Do not heat in a microwave or directly on the store. The heat will destroy nutrients and create hot spots that can burn your baby.
• Instead, place the sealed container of breast milk in a bowl of warm water or hold it under warm running water for a few minutes.
• Before you feed warmed milk to your baby, test the temperature by putting a few drops on your wrist. The milk should not be hot.
• Swirl the breast milk to mix the fat, which might have separated.

Extra effort that helps mothers and babies

While it does take extra steps to safely collect and store breast milk, there are a number of benefits to making the effort. Breast milk is beneficial to a baby’s well-being, especially in the first six months. Storing breast milk gives moms more flexibility and can improve a mother’s physical comfort. And mothers have the peace of mind knowing their child can have breast milk even when mom isn’t there.

Learn more about storing breastmilk & breastfeeding

• Use this easy-to-follow guide for storing breast milk. 
• Find more information here on how to keep a breast pump kit clean. 
• First 5 can connect expectant and new mothers to breastfeeding information and support. Some mothers may be eligible for post-partum home visits or WIC which provides breastfeeding support.
• The American Academy of Pediatrics also provides information for mothers who are breastfeeding.