If a water bottle is filled with water, then drunk. Will chemicals from the bottle itself be mixed in with the water? There has been much controversy at my school. It is said that chemicals from the bottle willed be mixed into the liquid, and when you freeze the bottle water. However, would it not be just as bad if drunk from a freshly openend water bottle?

Plastics normally contain other substances to keep them flexible; these are called "plasticizers" and small amounts of them do leach from the plastic under some conditions. However...

The leaching rate is more or less constant, and any leaching would certainly happen while the plastic was in contact with the water that the bottle was originally filled with. That's assuming (which I don't) that the manufacturers were so stupid as to use a plastic which leaches plasticizers at any significant rate. For one thing, if it did so, not only would the contents of the bottle be contaminated but the plastic would become brittle--and would probably crack or break open during shipping.

Again, I will emphasize that the rate of plasticizer leaching from food-grade plastic into water or any other food material is going to be close enough to zero to make no difference. Otherwise the plastic could not contain its contents for long!

Typically freezing will not cause the leaching rate to increase; instead, it will make the plastic less flexible in the same way that putting a wax candle in the freezer makes it more brittle.

I hope this helps!

Dan Berger