It's a milk formula for a 9 month baby. Are there any scientific reasons requiring to boil the water before mixing in the formula's powder? The baby already drinks the tap water as it is healthy for human consumption here in Switzerland


1 Answer 1


No, you need not boil the water, especially as your child is already nine months old.

The recommendation to always boil is just to be extra safe in reducing bacteria content. Note that even very clean tap or bottled water is not sterile and neither is water that has been boiled for a few minutes. In general the recommendation to wash / boil everything you give to your baby becomes quite futile around six months: the imune system should be quite developed and a child that crawls will put much more things (starting with the hands...!) in his mouth than a smaller infant.

However, you should always use fresh, cold water, never warm tap water, which may have higher contents of bacteria, microorganisms or heavy metals.

Simply warm the cold tap water to the temperature recommended by the formula manufacturer. Discard any leftovers.

Sources (in German):
Mütter- und Väterberatung des Kanton Bern (pdf)
Luzerner Kantonsspital (discussing a case very similar to yours)

  • As for the sources: I see you are in Lausanne, but my French isn't good enough to search for sources from the French-speaking part of Switzerland. I hope the ones in German (but from Switzerland) will help you nevertheless.
    – Stephie
    Commented Feb 27, 2016 at 20:46
  • 1 minute is sufficient to sterilise water, unless you live above 2000m, in which case you should boil water for 3 minutes. Commented Feb 28, 2016 at 11:25
  • Just check the news : there was a problem in le Locle last year. It can happen anywhere.
    – MakorDal
    Commented Feb 28, 2016 at 16:16
  • 1
    @MakorDal yes, accidents can happen. But the baby in question is drinking tap water anyway. So this does not apply specifically to formula.
    – Stephie
    Commented Feb 28, 2016 at 16:28
  • 1
    I just meant that it's better to check the news regularly, in case somethings happen. Not to stop using tap water.
    – MakorDal
    Commented Feb 28, 2016 at 16:30

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