Infant formula
Parents and child carers who use powdered infant formula should always use hot water to make up a feed. Formula powder isn't sterile, so occasionally it could contain harmful bacteria, which could make babies ill. Using water that is 70°C, or higher, will kill any harmful bacteria in the powder.
In practice, this means boiling at least 1 litre of water in a kettle and leaving it to cool for no more than half an hour.
Research funded by the Food Standards Agency has confirmed the importance of using hot water to make up powdered formula. But some parents aren't aware of this advice and may use cold water, or boiled water that has been cooled for longer than half an hour.
Ready-to-feed liquid formula, sold in cartons, doesn't need to be mixed and is sterile. But it's more expensive to buy than formula powder.
If you're making up powdered infant formula, follow the manufacturer's instructions on how much powder and water to use for each bottle. You should also do the following:
- Clean and sterilise bottles and teats before you use them.
- Use fresh tap water (don't use water that has been boiled before).
- Fill the kettle with at least 1 litre of water.
- Boil the water.
- Then leave the water to cool for no more than half an hour.
- Always put the water in the bottle first, before the powder.
- Cool down the milk by holding the bottom half of the bottle under cold running water, with the cap covering the teat. (This is to avoid scalding the baby.)
- Test the temperature of the formula milk on the inside of your wrist before giving it to a baby. It should be body temperature, which means it should feel warm.
- If there is any made-up formula milk left after a feed, throw it away. You should also throw away any milk that has been at room temperature for more than two hours.
For information on breastfeeding, call the National Breastfeeding helpline on 0300 100 0212 to speak to the nearest trained volunteer in your area.






