Formula Milk

There are many different types and brands of formula milk available in pharmacies and shops. If you decide to give your baby formula, use a first infant formula throughout their first year. Always check labels carefully to make sure you are buying a suitable milk for your baby.

For more information about formula milk, speak to your midwife or health visitor, or visit:

Powdered infant formula

Powdered infant formula is not sterile and needs to be made up at a temperature which will kill any potential bacteria present. Even when tins and packets of powdered infant formula are sealed, they can sometimes contain bacteria. It is therefore important to know how to make and store infant formula milk safely and reduce the risk of your baby becoming unwell with an infection.

To reduce your baby’s risk of infection:

  • all equipment needs to be sterilised
  • each bottle of formula milk should be freshly made when it is needed
  • leftover formula milk should be discarded at the end of a feed
  • unused bottles of formula milk should be discarded if they have been kept at room temperature for over 2 hours (bacteria multiply very fast at room temperature and can also survive and multiply when in the fridge)

It is also important to follow the manufacturer’s instructions very carefully and use the scoop provided. The amount of water and powder may vary according to the brand.

Do not:

  • add extra formula powder (this can make your baby constipated or dehydrated)
  • add extra water (too little powder may not give your baby enough nourishment)
  • add sugar or cereals to your baby's formula
  •  warm up formula milk in a microwave (it may heat the milk unevenly and burn your baby's mouth)

How to make a formula feed

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1.  Empty your kettle and refill it with at least one litre of fresh tap water from the cold tap. Do not use water that has been previously boiled or water that has been softened. Bottled water is not recommended to make up a feed as it is not sterile and may contain too much salt (sodium) or sulphate.

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2. Boil the water. Leave the water to cool in the kettle for no more than 30 minutes, so that it remains at a temperature of at least 70°C. If less water is used, the cooling time will be significantly shorter.

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3. Clean and disinfect the work surface you are going to use. It is also really important that you wash your hands with soap and water to stop bacteria spreading.

4. If you are using a cold-water steriliser, shake off any excess sterilising solution from the bottle and the teat, or rinse the bottle with cooled boiled water from the kettle (not the tap).

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5. Keep the teat and cap on the upturned lid of the steriliser. Avoid putting them on the work surface.

6.   Follow the manufacturer’s instructions and pour the correct amount of water into the bottle first. Double check the water level is correct. 

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7. Loosely fill the supplied scoop with the formula powder and level it off using either the flat edge of a clean, dry knife or the leveller provided. Follow the manufacturer’s instructions and only put the suggested number of scoops in the bottle.

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8. Holding the retaining ring, put it on the bottle and screw it on. Cover the teat with the cap and shake the bottle until the powder is dissolved.

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9. It is really important to cool the formula, so it is not too hot to drink. Cool the formula by holding the bottom half of the bottle under cold running water. Move the bottle about under the tap to ensure even cooling.

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10. Test the temperature of the formula on the inside of your wrist before giving it to your baby. It should be body temperature, which means it should feel warm or cool, but not hot.

11.  If there is any formula left in the bottle after a feed, throw it away.

12. To reduce the risk of infection, make up formula feeds as your baby needs them. One at a time.


Formula preparation machines

At present, there is no published research and insufficient evidence that these machines are safe to use when preparing infant formula. Powdered infant formula is not sterile and needs to be made up at a temperature which will kill any potential bacteria present. The Department of Health recommends that powdered infant formula is made up with a litre of freshly boiled water and left for no more than 30 minutes so that it remains at a temperature of at least 70°C. This will reduce the risk of your baby becoming unwell with bacterial infections, which can lead to sickness and diarrhoea.

For more information about the bacterial contamination of powdered infant formula, please visit:

Domestic hot taps

Powdered infant formula is not sterile and needs to be made up at a temperature which will kill any potential bacteria present. The water added to the bottle should be fresh (not re-boiled) and at least 70°C when the powdered infant formula is added. Although different brands of hot taps provide water at different temperatures and the time taken to fill a bottle varies, the limited research available suggests that powdered infant formula should be added:

  • immediately if volumes of 2 to 3oz (60 to 90ml) are being made up
  • after no more than 5 minutes for volumes of 4oz to 5oz (120ml to 180ml)
  • after no more than 10 minutes for volumes 6oz to 8oz (210ml to 240ml)

For more information about making up bottles of infant formula from hot taps and baby kettles, please visit:

Baby kettles

Evidence examining the safety of baby kettles is limited. If you plan to use one, please visit for further information

Bottled water

Cold tap water (boiled only once and cooled for no longer than 30 minutes) is best for preparing infant formula. However, in certain circumstances, you may need to use bottled water.

If you are using bottled water, you should:

  • use still water only, never use fizzy or sparkling water
  • always boil the bottled water before using it to make formula milk (bottled water is not sterile)

It is better not to use bottled water that is labelled as ‘natural mineral water’, as it can have higher levels of sodium and other minerals. However, it can be used temporarily to keep your baby hydrated if no other water is available.

Ready-to-feed liquid infant formula

  • Ready-to-feed liquid formula can be more convenient than powdered infant formula, but it is usually more expensive.
  • All feeding equipment will still need to be sterilised.
  • Ready-to-feed liquid infant formula is sterile until opened. However, once opened, it needs to be used more quickly than powdered infant formula.
  • Once opened, any unused ready-to-feed liquid infant formula that remains in the carton needs to be stored at the back of the fridge on the top shelf with the cut corner turned down. This should be used within 24 hours or discarded.

For more information about ready-to-feed liquid infant formula, please visit:

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