• Posted August 26, 2025

The Experts' Guide to Safely Pumping, Storing And Thawing Breast Milk

Breastfeeding offers many benefits, from emotional bonding to better nutrition and immune support. But for parents who need to pump and store breast milk, handling it safely is key.

“Parents often feel nervous about food safety when handling and storing their breast milk,” said Dr. Patricia Campbell, a pediatrician and lactation consultant at Children’s Hospital Los Angeles.

“Thankfully," she added in a news release, "Scientific organizations like the Centers for Disease Control and Prevention (CDC) help to provide straightforward guidance that anyone can access.”

Here’s what experts recommend for pumping, storing, and thawing breast milk safely:

• Wash your hands before pumping. If soap and water aren’t available, use hand sanitizer with at least 60% alcohol.

• Use clean, food-grade containers or breast milk storage bags. Avoid using food bags or bottle liners.

• Label each container with the date it was pumped and your baby’s name if sending milk to childcare.

• Don’t reuse storage bags — they’re single-use only.

• Clean and sanitize bottles after every use.

• Keep fresh and frozen milk separate — never mix them.

• Discard leftover milk after feeding instead of reheating it later.

To store breast milk safely, follow these guidelines from Children’s Hospital Los Angeles:

• Room temperature: Up to 77°F (25°C) for up to 4 hours

• Cooler with ice packs: Up to 24 hours

• Refrigerator (fresh or thawed milk): 40°F (4°C) for up to 48 hours

• Home freezer (attached to a fridge): 0°F (-18°C) for up to 3 months

• Deep freezer: -4°F (-20°C) for 6 to 12 months

Once thawed, breast milk should be used within 24 hours and never refrozen.

The best way to thaw breast milk is to place it in the refrigerator or swirl the container in a bowl of warm water.

Avoid boiling water or microwaves, which can overheat the milk and damage nutrients.

More information

The U.S. Centers for Disease Control and Prevention has more on breast milk storage and prep. 

SOURCE: Children's Hospital Los Angeles, news release, Aug. 22, 2025