Don't make more formula than you will need. Formula can become contaminated during preparation. If a large quantity of formula is prepared and not properly refrigerated, bacteria can multiply to very large numbers. The more bacteria there are, the greater the chances for foodborne illness. Preparing formula in smaller quantities on an as-needed basis greatly reduces the possibility of contamination. If using powder, reconstitute immediately before feeding. If using liquid concentrates or ready-to-feed products, follow label instructions provided by the manufacturer.
Don't put a bottle back in the refrigerator if the baby doesn't finish it. Harmful bacteria from a baby's mouth can be introduced into the bottle during feeding; they can grow and multiply even after refrigeration (some bacteria can grow at refrigerator temperatures) and reheating. The temperature that's needed to kill harmful bacteria is extremely high for consumption by a baby. Also, it's not a good idea to repeatedly reheat formula because lots of nutrients can be lost.
Don't feed a baby from a jar of baby food and then put it in the refrigerator. Saliva on the spoon may contaminate the remaining food. Instead, put a serving size on a dish. Refrigerate the food remaining in the jar. Throw away the food in the serving dish that's not eaten.
Don't use honey as a sweetener to entice babies to drink water from a bottle. Honey isn't safe for children less than a year old. It can contain the Clostridium botulinum organism that could cause serious illness or death.
NOTE: Juices that are fresh-squeezed and sold by the glass, such as at farmer's markets, at roadside stands, or in some juice bars, may not be pasteurized, or otherwise treated to ensure their safety. Warning labels are not required on these products. Young children should avoid these juices.
WARNING: This product has not been pasteurized and therefore may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems.
If you can't tell if a juice has been processed to destroy harmful bacteria, either don't use the product or boil it to kill any harmful bacteria.