Bisphenol-A is an ingredient in plastic, it is also a potent female sex hormone. This chemical causes obesity in rats, and lines up exactly with the human obsesity epidemic. It also causes enlarged prostate, reduced sperm count, and increased aggression in men. The government is of course not sold on this research, because the plastic lobby is extremely powerful and has well placed and well payed scientists in important positions. But this threat is very real, have a look at this article about the studies done by Fredrick vom Saal, one of the leading researchers on this issue.