How long should you sterilise baby bottles?

NHS guidance says to sterilise bottles and teats until your baby is at least 12 months old. “At least” matters: it is a minimum recommendation, not an instruction that every family should stop on the first birthday. Good hygiene and sterilising help reduce the chance of infection, but no routine can promise that equipment stays germ-free.

Cleaning comes before sterilising. Take feeding equipment apart, wash and rinse it thoroughly, then use a suitable sterilising method. The method time is a separate answer: equipment needs at least 30 minutes in cold-water sterilising solution, boil-safe items need at least 10 minutes of boiling, and steam or microwave cycles depend on the manufacturer's instructions for the appliance.

Sterilising equipment is also separate from preparing formula safely. A sterilised bottle does not make an incorrectly prepared feed safe. If your baby is premature, has a weakened immune system, is medically vulnerable or has a clinical feeding plan, follow the team’s advice before changing the routine. If your baby is unwell or feeding poorly, contact the clinical team, midwife, health visitor or GP rather than relying on general hygiene guidance.

Clean bottles before you sterilise them

Sterilising does not replace washing. Milk residue can remain in small spaces around teats, retaining rings and bottle threads, so separate the parts and clean them before every sterilising cycle.

The clean-first sequence

• Wash your hands and clean the work surface.
• Take the bottle apart and check the bottle and teat for damage.
• Wash every part in hot soapy water with a clean bottle brush.
• Rinse the parts in clean, cold running water.
• Sterilise the cleaned parts using a suitable method.

Inspect the parts as you go. Damaged bottles or teats may not be suitable for continued use, and each item’s instructions should guide compatibility with your chosen sterilising method.

Clean bottles, teats and their separate parts before using a suitable sterilising method.

Does a dishwasher sterilise baby bottles?

A dishwasher can clean bottle-feeding equipment, but NHS guidance says it does not sterilise it. Do not treat a high-temperature or “sanitising” programme as a sterilising shortcut.

How long each sterilising method takes

Method duration is measured in minutes or by an appliance cycle. It is not the same as the age until which you continue the routine. Follow the instructions for the steriliser, solution and feeding equipment you actually use, because operation and compatibility vary.

Cold-water sterilising solution

Follow the product instructions when making the solution. Renew it every 24 hours, remove trapped air from the equipment, keep every part fully submerged and allow at least 30 minutes.

Afterwards, NHS guidance says you can shake off excess solution or rinse the equipment with cooled boiled water from the kettle. Do not rinse it with tap water, and do not improvise the solution strength or mixing ratio.

Follow the exact steriliser or solution instructions because operation, compatibility and timing vary.

Steam and microwave sterilising

There is no single steam or microwave time that applies to every appliance. Use the manufacturer’s cycle, loading and compatibility instructions for your model, including the direction in which openings should face. Take care around heat and steam, and do not guess water quantities, wattages or cooling times.

Boiling

Only boil equipment that its instructions confirm is boil-safe. Keep the items fully submerged for at least 10 minutes, never leave a hot pan unattended, and check parts afterwards because repeated boiling can make teats deteriorate more quickly.

Handling parts after sterilising

Clean handling helps reduce recontamination. Wash your hands, use a clean disinfected surface, keep teats and caps off the worktop, and hold a retaining ring by its edge. Where practical, keep equipment in the steriliser or pan until needed. If you remove it, cap or assemble it promptly with clean hands.

These steps reduce the chance of contaminating the parts again, but they do not create a guaranteed number of hours for which equipment remains sterile.

What the 12-month advice covers

The NHS advice specifically names bottles and teats. Related guidance also covers relevant milk-contact feeding equipment used for expressed breast milk or first infant formula, but that does not mean one rule automatically applies to every item a baby uses.

Why “at least” matters

Continue sterilising bottles and teats until your baby is at least 12 months old. The wording does not set an automatic stop date on the first birthday, and the NHS guidance cited here does not set out one universal routine for every family after that point.

If you are unsure whether to continue, check the current NHS advice and discuss your baby’s circumstances with a health visitor, midwife, GP or existing clinical team before changing the routine.

How often for formula-feeding equipment

NHS formula-feeding guidance says bottles, teats and other feeding equipment should be washed and sterilised before each feed. Do not cut back early just because your baby has started solids or seems well.

Which feeding equipment is included?

This advice covers bottles, teats and relevant parts that come into contact with expressed breast milk or first infant formula. For breast-pump parts, follow the pump’s cleaning, sterilising and compatibility instructions.

Do not assume the 12-month bottle-and-teat rule automatically covers dummies, every pump component, all weaning equipment or everything your baby puts in their mouth. Check the guidance for the specific item.

When sterilising guidance is not enough

Bottle hygiene is important, but it cannot answer every feeding or health question. Keep the equipment routine alongside, rather than in place of, the separate formula-preparation process and any individual clinical advice.

Sterilising is not the same as preparing formula safely

A sterilised bottle does not make an incorrectly prepared formula feed safe. Powdered formula can contain bacteria and has its own NHS preparation process, so follow the current NHS guidance on making up a bottle feed as well as the instructions on the formula packaging.

When your baby’s clinical plan comes first

A baby who is premature, has a weakened immune system, is medically vulnerable or is receiving neonatal or other clinical care may need extra precautions or an individual feeding-hygiene plan. Follow the plan from the team caring for your baby and ask that team before changing the age, frequency, method or handling routine.

General guidance cannot assess your baby’s immune status or replace a neonatal or clinical plan. A device manufacturer can advise on operating a product, but cannot give individual medical advice.

If your baby is unwell or feeding poorly

Sterilising more often is not a treatment and general bottle-hygiene information cannot assess an unwell baby. If your baby is unwell, feeding poorly or you have a clinical concern, seek timely advice from the existing clinical team, your midwife, health visitor or GP.

Frequently asked questions