How to Make Up Formula Safely (NHMRC Guidelines) | Parenting Hub
Step-by-step safe formula preparation, storage rules and what to avoid. Based on NHMRC and Royal Children's Hospital guidance.
Formula isn't sterile — bacteria can survive in powder. Following safe preparation prevents serious infections in babies under 6 months especially.
Sterilising
Sterilise bottles, teats, lids and rings for every baby under 12 months. Wash first in hot soapy water, then steam, boil or chemical-sterilise. Air-dry on a clean rack.
Making up a bottle (NHMRC)
- Boil fresh tap water and let it cool to at least 70°C (about 30 minutes after boiling — no longer)
- Pour the water into the sterilised bottle first
- Add the exact number of level scoops (1 scoop per 30mL water — never pack or heap)
- Cap and shake until dissolved
- Cool under cold running water to body temperature — test on inner wrist
- Use within 1 hour; discard any leftovers from the feed
Storage rules
- Made-up formula: best fresh, but if refrigerated immediately can keep 24 hours at <5°C
- Don't reheat in a microwave (hot spots burn baby's mouth) — stand bottle in warm water
- Never re-use leftover milk from a previous feed
- Out and about: carry cooled boiled water and powder separately; mix when needed
Common mistakes
- Adding water to powder (wrong concentration)
- Using bottled mineral water (sodium too high)
- Scooping with packed or heaped scoops
- Letting water cool below 70°C before mixing (doesn't kill bacteria in powder)
When to seek help
- Baby with vomiting, diarrhoea or fever after a formula feed
- Baby refusing feeds with lethargy
- Persistent green or bile-stained vomit
Common questions
Can I use ready-to-feed formula?
Yes — it's sterile until opened. Once opened, treat like fresh formula and use within 1 hour at room temp.
Is tap water safe?
Yes in Australia, after boiling and cooling. Don't use water that's been sitting in the kettle for hours — re-boil fresh.