Parents and pediatricians today are not as concerned with sterilizing bottles and water as they were a generation ago, but many are now having second thoughts in light of recent reports of contaminated city water supplies and increased concern over food safety.
For starters, always wash your hands before handling baby bottles or feeding your baby.
If you use disposable plastic bottle liners and ready-to-use formula, you still need to make sure the nipples are clean. Scrub them in hot, soapy water, then rinse to get rid of all traces of soap; some experts recommend boiling them for 5 minutes.
Always wash and thoroughly rinse and dry the top of the formula can before you open it; make sure the can opener, mixing cups, jars, spoons, and other equipment are clean.
Glass Bottles & Formula Safety
If you use regular glass bottles and concentrated or powdered formula, you must make sure that the bottles and water added to the formula are germ free. You don't need to boil the bottles; you can put them, along with mixing cups and other equipment used to prepare formula, in a dishwasher that uses heated water and has a hot drying cycle. Or you can wash the bottles in hot, soapy water and rinse thoroughly. This alone should kill most germs.
Mixing with Water
Water for mixing infant formula must be from a safe water source as defined by the state or local health department. If you are concerned or uncertain about the safety of tap water, you may use bottled water or bring cold tap water to a rolling boil for 1 minute (no longer), then cool the water to room temperature for no more than 30 minutes before it is used. Warmed water should be tested in advance to make sure it is not too hot for the baby. The easiest way to test the temperature is to shake a few drops on the inside of your wrist. Otherwise, a bottle can be prepared by adding powdered formula and room-temperature water from the tap just before feeding. Bottles made in this way from powdered formula can be ready for feeding because no additional refrigeration or warming would be required.
Storing Prepared Formula
Prepared formula must be discarded within 1 hour after serving a baby.
Prepared formula that has not been given to a baby may be stored in the refrigerator for 24 hours to prevent bacterial contamination.
An open container of ready-to-feed, concentrated formula, or formula prepared from concentrated formula, should be covered, refrigerated, and discarded after 48 hours if not used.