If it is in the refrigerator, pre-mixed formula (also called ready-to-feed formula) that is opened must be thrown out after 48 hours. Formula that you mixed must be thrown out after 24 hours. If your baby does not drink all the formula within one hour, throw it out.
http://pregnancyandbaby.com/baby/articles/945875/top-5-baby-formula-safety-mistakes
Q. Sometimes after my son finishes his midnight bottle, I fall asleep without putting the remaining formula away. A. Opened formula, either ready-to-feed or liquid concentrate, shouldn't be left at room temperature longer than two hours—and no more than an hour if the room is warm.
http://www.parenting.com/article/what-to-expect-when-does-formula-spoil
Mistake #3: Keeping mixed formula out too long. Formula that is sitting out at room temperature must be thrown away after 1 hour. If it is in the refrigerator, pre-mixed formula (also called ready-to-feed formula) that is opened must be thrown out after 48 hours. Formula that you mixed must be thrown out after 24 hours. Mistake #4: Re-using leftover formula. If your baby does not drink all the formula within one hour, throw it out.
http://pregnancyandbaby.com/baby/articles/945875/top-5-baby-formula-safety-mistakes
On a message board I frequent, a mother recently asked how many of us obey the “don’t feed formula left out over 2 hours” rule. While most people responded that they did abide by this recommendation, a conversation ensued about why we we’d all been told to do this.
http://www.fearlessformulafeeder.com/2011/08/the-2-hour-rule-is-a-bottle-safe-when-its-been-left-out-too-long/
For a snacker like Fearlette is – especially one on $30-a-can Alimentum – this rule is a real drag. My sick little theory was that this rule is all b.s., a combined ploy of the formula manufacturers and breastfeeding pushers who want to make it more costly and aggravating to formula feed.
http://www.fearlessformulafeeder.com/2011/08/the-2-hour-rule-is-a-bottle-safe-when-its-been-left-out-too-long/
I couldn’t find any documentation of cases where children got sick from formula left out of the fridge too long, or suffered long-term health effects because their parents let them drink a bottle they’d been snacking on for 2 hours and 15 minutes.
http://www.fearlessformulafeeder.com/2011/08/the-2-hour-rule-is-a-bottle-safe-when-its-been-left-out-too-long/
Does anyone know how long you can keep made-up formula in the fridge for? I am sure i have read somewhere that once made up it can be stored in the fridge for upto 24 hours. I have just seen on Cow & Gate's Website that you should only keep it for 2 hours after making it up, even if kept in the fridge. Our little girl is almost 4 weeks old and unfortunately I haven't been able to breastfeed. We are currently using Cow & Gate's newborn Formula for Hungry Babies.
http://babyandbump.momtastic.com/baby-club/34751-can-you-keep-formula-fridge.html
Either feed immediately or cover and store in refrigerator for no longer than 24 hours. Do not use prepared formula if it is unrefrigerated for more than a total of 2 hours. AFTER THE FEEDING BEGINS... do not refrigerate bottle.
https://answers.yahoo.com/question/index?qid=20060621194116AAThUqJ
Even properly refrigerated liquid formula should be used within 48 hours; if you've made a batch from powdered formula, you should use it within 24 hours. Remaining powdered formula should be used within a month after opening. Any formula left in the bottle an hour after your baby has started feeding should be discarded, so try not to fill the bottle with more than he usually takes. And as with any food, particularly one meant for a baby: When in doubt, throw it out. Contributing editor Heidi Murkoff is the coauthor of the bestselling What to Expect When You're Expecting (Workman) and the author of the What to Expect Kids series of children's books (HarperCollins).
http://www.parenting.com/article/what-to-expect-when-does-formula-spoil
But after that… I don’t know. The fact is, once your kid is on solids, they are going to be at risk for foodborne illness from all sorts of products, not just infant formula. I haven’t found any research that makes me believe Fearlette is at risk because I let her snack on the same bottle for 3 hours rather than 2.
http://www.fearlessformulafeeder.com/2011/08/the-2-hour-rule-is-a-bottle-safe-when-its-been-left-out-too-long/
how many hours formula bottle out of refrig
Keep a formula bottle out of refrigerator for two hours. Formula Bottle out of refrigerator for two hours.