There are three basic safety rules to follow when preparing a bottle:

1. Always wash hands before and after feeding.
2. Read the directions and prepare correctly, when using formula.
3. Never use a microwave to warm bottles; instead use a bottle warmer or warm water on top of the stove.

Visit the Food and Drug Administration (FDA) for more infant formula preparation information.

Parents should follow these guidelines when storing breastmilk:

• Freshly Pumped Milk – Freshly expressed milk can safely sit at room temperature for 3-4 hours, then should be refrigerated or frozen.
• Refrigerated – Breast milk can remain safe in the refrigerator for about 3-5 days, according to the American Academy of Pediatrics.
• Frozen – Frozen breast milk can be stored at 0° F for 6-12 months.
• Thawed – Breast milk should be thawed in the refrigerator, and fed within 24 hours.

Once a bottle of infant formula is prepared, it has a finite amount of time for use. Following are guidelines on how quickly to use or dispose of infant formula once it is prepared.

• Powdered – A prepared bottle of powdered infant formula that has been refrigerated should be used within 24 hours; follow instructions on the label. Prepared formula that has been at room temperature should be used within one hour. The remaining powdered infant formula should be tightly covered, stored in a cool, dry place and used within a month after opening.
• Liquid Concentrate – An open can of liquid concentrate infant formula is safe to use for up to 48 hours. The remaining formula should be tightly sealed and placed in the refrigerator immediately after opening. A prepared bottle of liquid infant formula should be used within 48 hours.
• Ready-to-feed Liquid – Ready-to-feed infant formula should be fed within two hours after preparing a bottle. Any formula not used to prepare a bottle should be refrigerated immediately and used within 48 hours.

Freezing infant formula is not recommended. Though freezing does not affect the safety or quality of the formula, separation of the product’s components (e.g., fats, proteins) can occur when the formula is thawed. This may result in a baby receiving fewer nutrients. Also, the flow of milk through the bottle’s nipple may be slower, making it harder for a child to suck.

Formula Shelf-Life
All infant formulas have a “use by” date on the container. Formula should not be bought or used beyond this date, as some nutrient levels may decrease and there may be changes in physical properties, such as discoloration and separation of fat.

Infant formula companies have a reimbursement program for outdated products, as well as policies that encourage stores not to sell products past their use by date. Some states have also passed laws prohibiting stores from selling outdated products, including expired formula. If formula is out-of-date at the time of purchase, parents should return it to the store from which it was purchased for exchange or reimbursement, or contact the manufacturer directly.