A very eco-friendly (heck, a generally-friendly) friend of mine was proudly showing off his fancy metal water bottle to me the other day. I (foolishly) tried to out-eco him and showed him the standard 2-litre plastic bottle that I’ve been using for half a year or so. He looks shocked and tells me this is carcinogenic and dangerous.
I’ve heard this claim before somewhere, and I remember distrusting it. Google is giving me unreliable results: half are claiming it’s a hoax and half say that it’s for real.
I don’t know enough to sort the wheat from the chaff. Help me, SDMB. Assuming I keep the bottle fairly clean, is it dangerous to re-use plastic bottles?
Conventional spring water bottles are generally made from polyethylene terephthalate (PET), which isn’t associated with the bisphenol A (BPA) recently highlighted by the media as a potential health risk. However a separate concern does exist in the estrogen-like chemicals these leach in contact with water, whose long term health effects are unknown. These levels were sufficient to persuade the researchers of a recent study to drink tap water instead. Note that many metallic containers now come with epoxy linings, which could also leach similar unwanted contaminants, so if you’re really paranoid a stainless steel container is probably the best alternative.
Your friend may be conflating some info about polycarbonate bottles that were made with bisphenol A (BPA). These were the tough re-usable polycarbonate water bottles made by companies that included Nalgene. Here’s a quickie article that’s reasonably detailed. You’ll recognize the bottles in the pictures: all colorful and re-usable.
This resulted in a voluntary recall by some retailers, like Mountain Equipment Co-op, when the story broke, until further studies could refute or corroborate the claims. Nalgene and most other manufacturers now make BPA-free bottles, but if you have an older polycarbonate bottle, you may want to get rid of it and get a new one.
Regular plastic bottles are a different plastic altogether.
If we’re talking about the re-use of plastic bottles like you buy by the case at the store, I find the claim of danger to be not plausible.
It seems to me that the highest leaching out of the plasticizing chemicals would be when 1) the bottles are new, and 2) when the water has been sitting in the bottle the longest. Both of these conditions would imply that it’s more dangerous to drink out of them right from the store, and less dangerous to refill them yourself.
I’ve always been told that the use-by date on water bottles is because, if they sat unopened that long, enough chemicals would have leached into the water for them no longer to be safe.
Seeing as these dates are usually two years in the future, I doubt you have much to worry about.