Before making up the formula:
• Make sure the powdered formula is stored in a clean dry place. Keep the formula covered, and check the use-by date. Use the powder within 4 weeks of opening the tin.
Uncovered formula can become contaminated by bacteria or viruses carried on dust particles in the air or present in the environment.
• Sterilise bottles and teats (ask your Lead Maternity carer, Well child nurse or chemist for more information on how to do this if you’re not sure).
• For at least the first 3 months, all water (including bought water) used to make up formula should be boiled and cooled on the day it is used. Boil for 3 minutes on the stove top or until an automatic kettle switches off. Keep boiled water covered while it cools and until you need to use it.
• Water from tanks or bore holes should still be boiled and cooled for babies and toddlers until they are about 18 months old.
Unboiled water and unsterilised bottles can carry bacteria and viruses that can make baby ill.
Mixing the Formula:
• Always wash your hands thoroughly before preparing bottle feeds. Keep everything you use to make up baby’s feeds clean. Be especially careful in the first 3 months.
• Make up the formula carefully using the boiled, cooled water you have already prepared and following the instructions on the packaging exactly. Infant formula is balanced for baby’s nutritional needs, a stronger or weaker formula can harm baby.
• If baby is hungry and demands more, give more formula at each feed or give them an extra feed. Do not alter the formula strength.
• We recommend that you only prepare the amount you need for baby’s next feed, and that you prepare it as close as possible to feeding time.
Warming the Formula
• Formula can be heated by placing the bottle in a container of hot water.
• Microwaves can heat unevenly. If using a microwave, prepare the milk in a clean jug and pour it into the bottle before use, or at least shake the milk thoroughly after heating and leave to stand for 2 - 3 minutes. Shake again before using.
• Test the temperature of the milk on your skin – it should feel just warm (about body temperature).
• Use warmed formula within 20 minutes.
• Some babies may be quite happy fed with milk at room or fridge temperature.
Handling Prepared Formula:
• Throw out any formula that is left in the bottle after a feed, and wash and resterilise the bottle. Never reheat formula that has already been warmed or offered for feeding.
If you have to prepare a bottle in advance:
• If you have to prepare a bottle in advance (for a baby-sitter, or to take out with you), keep the prepared bottle at 4°C in the back of the fridge (check your fridge temperature).
• If carrying a bottle with you, keep the bottle cold in a chilly bin or insulated carrier.
• Throw out any prepared formula that’s been out of the fridge for more than 4 hours.
• Prepared formula should not be kept in the fridge any longer than 24 hours and ideally shorter times are better.
The temperature that babies like their formula is also a perfect temperature for harmful bugs to grow. Following the above guidelines means you will generally not be giving the bacteria a chance to grow to levels that can make baby sick. Please keep in mind that although infant formula powder is pasteurised it is not sterile (it can contain very low levels of bacterias) and in addition, there are lots of ways powder can accidentally be contaminated in the home. By taking care with handling and storage of prepared formula you can still protect baby from foodborne illness.