There's been a lot of talk recently about bisphenol A, or BPA, which is most commonly found in polycarbonate plastics. These are the plastics used in baby bottles and Nalgenes, the kind that are rigid and unlikely to break when dropped. BPA has been found to disrupt the processes of the endocrine system in animals, but it is still unclear what, if any, the effect on humans is. Still, the news today is that the Canadian government is poised to declare the chemical as toxic when used in food and water containers because it leeches out into its container's contents. We've all tasted plasticky water after having left a bottle in the car all afternoon—part of that taste is BPA.
There is concern that its effects may not be limited to endocrine processes, potentially affecting neural pathways as well. Even very small amounts have been shown to change animals' bodies, so the Canadian government's assumption is the likely effect on humans—particularly infants and children—is not insignificant.
That said, the animals in the bulk of the studies done on BPA have been rats, whose bodies reabsorb the metabolized compounds through their guts and into their bloodstreams. In humans, however, the compounds are quickly excreted in the urine and typically have an elimination half-life of less than 6 hours. For that reason, the European Food Safety Authority has concluded that even in high exposure instances, the detrimental effects are presumed to be very low.
Once the announcement is released, there will be a public comment period, followed by a legislative process which could take up to two years. The end result will likely be a ban or partial ban on food-related uses of BPA plastics.
Via NY Times
My conversion to reusable leach-free aluminum Swiss-made Sigg bottles has more to do with concerns over environmental waste than health effects, because when it comes to poisonous stuff in the environment plastic is the least of our worries. Suffice to say, I haven’t been following the BPA news closely -- I'm too busy looking for trans fat in my food -- but if the stuff DELAYS puberty, as the research suggests, then perhaps it will serve as a nice counter balance to all the estrogen-pumping chemicals in the environment that are sending five year girls to the bra store. The bottom line is this: Plastic is bad for you, especially when it’s exposed to UV rays, and you’re a fool if you’re waiting for the government to confirm it.
I've been looking for an alternative to the Nalgene-type bottles forever, too, and almost settled on Sigg... until I found out it had a plastic-lined interior. They have now switched to a water-based interior lining, but it still points to the difficulties of all of this. Every new thing that comes out seems to have a new potential toxin in it. Which is why, I guess, we need things like the FDA -- or the Canadian FDA -- in the first place.
(And I've ended up with the Kleen Kanteen).
It's really way too early to say anything about the harmful effects on this. The researcher who started this controversy was a Masters student with highly questionable lab practices. The incredibly low amounts of BPA he found in his studies could easily have come from lab contamination if he was not incredibly careful. Much ado about nothing.