Using formula within 4 weeks of opening

[maswera]

DS's nursery gave me half a box of formula back today because it has been open for 4 weeks, which surprised me a bit. I mostly bf him so have had boxes on the go for probably a couple of months in the past. Would it be so terrible to feed him stuff that's been open for a bit longer than it should be...?

[RitaMorgan]

I wouldn't risk it personally.