Refrigerated Storage Duration for Infant Formula
Ready-to-feed formula and reconstituted powdered formula can be safely stored in the refrigerator for up to 24 hours at 4°C or below, after which any unused formula must be discarded. 1
Ready-to-Feed Formula Storage
- Once opened, ready-to-feed formula must be stored at 4°C or below and used within 24 hours. 1
- Any formula remaining after this period should be discarded to prevent bacterial proliferation, as milk products are excellent media for bacterial growth. 1
- Ready-to-feed formula is sterile until opened, unlike powdered formula which is never sterile. 2
Reconstituted Powdered Formula Storage
- Powdered infant formula mixed with water should be prepared fresh for each feeding whenever possible, especially for infants younger than 2 months. 1
- If advance preparation is necessary, reconstituted powdered formula can be stored at 4°C or below for up to 24 hours maximum. 1
- The 24-hour limit applies whether the formula is prepared at home or in institutional settings. 1
Critical Safety Considerations
Powdered infant formula is not sterile and may contain pathogenic bacteria such as Cronobacter spp. (formerly Enterobacter sakazakii), which can cause devastating sepsis, meningitis, brain abscesses, and necrotizing enterocolitis with mortality rates of 33-80%, particularly in infants under 2 months. 1
- Bacterial multiplication occurs rapidly in prepared formula at room temperature, making proper refrigeration essential. 1
- The risk is highest during the first 2 months of life when immune systems are most vulnerable. 1
What NOT to Do
- Never keep formula warm in bottle warmers or thermos bottles, as this creates ideal conditions for bacterial growth. 1
- Never use formula that has been left at room temperature for more than 2 hours. 2
- Discard any formula remaining in the bottle after a feeding rather than refrigerating it for later use. 1
- Do not store formula for longer than 24 hours even if refrigerated properly. 1
Institutional vs. Home Settings
- In hospitals and institutions, written guidelines should mandate daily preparation of formula with storage at 4°C or below. 1
- For home use, fresh preparation for each feeding is strongly preferred over batch preparation and refrigeration. 1
- Sterile liquid ready-to-feed formula is encouraged for healthy newborns in maternity wards to minimize infection risk. 3