Breast Milk and Powdered Infant Formula Storage Guide

Summary:

This educational guide provides a practical overview of safe breast milk and powdered infant formula storage based on CDC-referenced guidance.  It is designed to help educate parents and caregivers on evidence-based practices that support infant safety and nutrition. 

Watch our short video for additional education on this topic.

Key Takeaways:

• Store freshly expressed or pumped breast milk for up to 4 hours at room temperature (77°F/25°C or lower), up to 4 days in a refrigerator (40°F/4°C), and use it within 6 months when frozen, though it is acceptable for up to 12 months. 
• Thawed breast milk should be used within 24 hours if thawed in the refrigerator and within 2 hours after warming or reaching room temperature. Never refreeze thawed human milk.
• Use prepared powdered infant formula within 2 hours of preparation, within 1 hour after feeding begins, or refrigerate immediately after preparation and use within 24 hours. Do not freeze prepared powdered infant formula.

Related Questions & Answers

• How long can freshly expressed breast milk be stored safely?
  Freshly expressed breast milk can be stored for up to 4 hours at room temperature (77°F/25°C or lower), up to 4 days in a refrigerator maintained at 40°F/4°C, and in a freezer where it is best used within 6 months but acceptable for up to 12 months.
• How long can prepared infant formula be kept before it should be discarded?
  Use prepared infant formula within 2 hours of preparation when stored at room temperature, and within 1 hour after feeding starts. Discard any leftover formula from a feeding. You may use formula refrigerated immediately after preparation within 24 hours.

References:

• Centers for Disease Control and Prevention. Breast Milk Storage and Preparation. CDC. Updated August 14, 2026. Accessed May 1, 2026. https://www.cdc.gov/breastfeeding/breast-milk-preparation-and-storage/handling-breastmilk.html  
• Centers for Disease Control and Prevention. Infant Formula Preparation and Storage. CDC. Updated May 14, 2026. Accessed August 27, 2026. https://www.cdc.gov/infant-toddler-nutrition/formula-feeding/preparation-and-storage.html
• U.S. Food and Drug Administration. Handling Infant Formula Safely: What You Need to Know. FDA. Accessed May 1, 2026. https://www.fda.gov/food/buy-store-serve-safe-food/handling-infant-formula-safely-what-you-need-know.html