So I just wanted everyone to know the risks with old bottles. A couple had their first child, when the baby was only weeks old it had passed away because they gave their child old formula. They don't know whether it was left in the car too long or sat out over night. It grew bacteria unbeknownst to them and they fed it to their child. The bacteria with in a day ate through their baby's brain and he was pronounced brain dead the next day. They had to take him off life support. This is such a tragic event and couldn't imagine not knowing you were feeding your child poison. Obviously we all know you can not feed a child old formula (1-2 hrs old) but having a new born is not easy and accidents happen. You get tired and at 4am maybe don't feel like making a new bottle and grab the one from earlier in the night. I just want you ladies to know the risks. So scary.