Why is it important to clean and sterilise my baby’s bottles?
Milk is the perfect medium in which bacteria can grow. This is why it’s important to clean and sterilise equipment that has been in contact with milk.
You can help reduce the chance of your baby getting sick by always using a sterilised bottle and clean equipment.
Even if bottles and teats look clean, they might still carry germs.
What equipment needs cleaning and sterilising?
You need to clean all bottle parts, teats and screw caps after every use.
If your baby’s bottles have not been used after 24 hours, you’ll need to sterilise them again.
If you are expressing breast milk, you will need to clean the expressing equipment at least once every 24 hours. You shouldn’t need to sterilise your own personal expressing equipment if your baby is healthy and was born at full term.
If you or your baby are sick or they were premature (born early) talk to your doctor or child health nurse about cleaning and sterilising your expressing equipment.
Washing baby bottles
Keep a bottle brush just for this purpose. Get a new bottle brush once the bristles are worn. After washing the bottles you’ll need to sterilise them.
- Separate all parts of the bottle and pull the teat out of its screw cap.
- Use hot water and dishwashing detergent.
- Clean all areas of the bottle with a bottle brush, including the thread where the cap screws on.
- Remove any milk still sitting in the teat or the hole.
- Squeeze hot, soapy water through the teat hole, then do the same with clean water to rinse the teat.
- Make sure to rinse everything well.
How do I sterilise equipment used for formula feeding?
There are 3 ways to sterilise your equipment:
- steam sterilisation
- chemical sterilisation
Take care to avoid scalds. Keep children away from hot or boiling water.
If you’re breastfeeding and only need to sterilise your bottles occasionally. The boiling method may be suitable for this. This will save you the cost of buying a steam steriliser or chemicals.
The boiling method
- Put all parts of the cleaned bottle, including teats, in a large saucepan.
- Add enough tap water to cover the equipment.
- Make sure there are no air bubbles.
- Bring the water to the boil and boil with the lid on for 5 minutes.
- Let the feeding equipment cool in the saucepan before taking it out and letting it air dry.
- Place the sterilised feeding equipment in a clean container with a lid.
The steam sterilisation method
Steam sterilisers are popular because they work quickly, are cheap to use. They heat water to boiling point and the steam kills the bacteria. Some steam sterilisers are designed to operate in a microwave. Choose one that meets Australian Standards.
- Place the clean bottles and feeding equipment in the steriliser.
- Make sure there’s enough room between each bottle, teat and screw cap for the steam to circulate around all surfaces.
- Follow the manufacturer’s directions about how much water to add.
- If you’re using a microwave steriliser, place the steriliser in the microwave.
- Turn on the steriliser or microwave for the correct time.
- When the cycle is complete store the equipment in a clean container with a lid.
The chemical sterilisation method
Be careful when using chemical sterilisation. Many methods use bleach. Keep chemicals out of reach of children.
Antibacterial chemical sterilisation solutions are available in liquid and tablet form. They need to be prepared exactly as directed on the container.
- Use a plastic or glass container that’s large enough to hold your baby’s bottles and feeding equipment.
- Make a fresh batch of solution every day.
- Place the clean bottles and feeding equipment in the solution. Make sure there are no air bottles and everything is covered.
- Leave the equipment in the solution for the recommended time — there’s no need to rinse the solution off after sterilisation.
- Throw out the solution after 24 hours and wash out the container before preparing a new batch.
How do I clean equipment used for expressing breast milk?
You will need to clean:
- the milk collection parts of your hand pump, electric pump or milk catcher
- all reusable containers used to collect or store your breastmilk
Follow these steps:
- Wash and dry your hands.
- Take apart all containers and the breast pump.
- First rinse everything in cold water to remove milk.
- Use hot water and dishwashing detergent and a bottle brush to carefully remove all traces of grease, milk and dirt.
- Rinse at least twice with hot water.
- Drain on clean paper towel or a clean cloth towel. Cover while they air dry.
If you’re using an electric breast pump, check the instructions provided.
How do I store the feeding or expressing equipment?
Store the dry sterilised feeding equipment in a clean container with a lid. You can keep it in the fridge for up to 24 hours. You will need to sterilise your bottles every day.
Store the clean dry expressing equipment in a new plastic bag or clean covered container until you need to use it again.
Make sure you wash and dry your hands before you handle sterilised bottles and teats. It’s easy to contaminate equipment just by touching it with dirty hands.
Resources and support
For breastfeeding support you can contact:
- a registered lactation consultant
- the Australian Breastfeeding Association Breastfeeding Helpline: 1800 686 268 (1800 mum 2 mum)
Speak to a maternal child health nurse
Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.
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Last reviewed: August 2023