A recent study done by scientists from the University of Florida has warned not to drink water from a bottle if it was left somewhere warm for a long time. The study also suggested that when you heat plastic for a long duration of time or when plastic is subjected to be kept in a warm atmosphere, it tends to release chemicals antimony. This happens because plastic water bottles are made from polyethylene terephthalate.
Antimony is considered a carcinogen by the International Agency for Research on Cancer,part of the World Health Organization.While the US Food and Drug Administration has said BPA is not a major concern at low levels found in beverage containers, it continues to study the chemical's impacts.
Plastic containers and bottles are very popular nowadays as they could easily be carried from one place to the other. Their convenience and perceived purity which has been portrayed by effective marketing strategies. But, as per the Natural Resources and Defense Council, consumers should never believe that bottled water is the purest form of water than the tap water.
Reusing plastic drink bottles, that too which is said to be hot is not recommended, as it may elevate the likelihood of impure substances due to the formation of bacteria and leaching of plastic material into the water.