I have recently heard that it is a bad idea to reuse plastic bottles because of a chemical in the plastic that can get into the water that is bad for you...can cause breast cancer or something. Has anyone else heard this same thing? I've been kind of worried ever since I heard that because often times I can't finish a whole bottle in one sitting so it sits at room temperature for about a day before I put it back in the fridge to later finish. Am I making a fuss about nothing here or is this something I stop doing?