Some plastic water bottles have dangerous chemicals in them.Look at the number on the bottom of the bottle, if the number is a 1, the water bottle is recommended for one use only.If it is a 2, 4, or 5 than the bottle is safe to refill and reuse.If the number is a 3 or a 6 then the bottle is potentially dangerous. If the number is a 7, the bottle contains a dangerous chemical called Bisphensol A (BPA ). Since most disposable plastic water bottles are made from type 1 plastic, people throw them away more, and they end up in landfills.These bottles are filling up our landfills! They do not disintegrate easily! Buy a safe, reusable plastic bottle and HELP US GO GREEN!