The thinning of commercially sold plastic water bottles was not to make them safer, but to reduce packaging costs. They then marketed it as a more environmentally friendly bottle. The water seller wins on both sides, lower cost of a bottle, and better PR with the consumer.
To my knowledge there are no PCB’s in PET.
But it is probably aluminium and you’ll get old timers!
I don’t know about other plastic types, but I have researched BPA in the past, and the results I found were that yes, BPA is a toxic substance, but the amount of BPA you get from a plastic water bottle (or plastic baby bottle) is so minuscule as to be far, far below the amount needed to cause concern. The Canadian ban on BPA in baby bottles is bowing to junk science hysteria.
I used to work in environmental toxicology, and we used a test using sea urchin gametes as a quick and sensitive test for toxicity in aqueous samples. We found that if we bought new HDPE sample bottles, and put water in them, then used the water for testing, that the water would be toxic, but that if we soaked the bottles for a few days with several rinses, the toxicity would disappear. Every time we’d get a new batch of sample bottles in, we’d be soaking them to remove the toxicity. We did not get the same effect with polycarbonate by the way, but those bottles did not work for us for other reasons, mainly cost.
We never determined what was causing the toxicity from the HDPE, but we never saw it in older bottles that had been washed and reused (includes acid washing and acetone rinse). But even a normal acid wash and acetone rinse would not remove toxicity from new HDPE - it had to soak for a long time. I suspect phthalates, but I don’t really know.
That said, there are probably a lot of things that kill sea urchin sperm that would not effect a human. Humans are pretty tough, contaminant-wise. But it always made me leery about HDPE milk bottles, enough to buy milk in glass when our kids were small. I’m pretty sure they don’t soak those bottles for days before the load the milk in.
Incidentally, I believe that milk in cartons has plastic instead of wax coating now, and probably is loaded with BPA. So cartons probably won’t help.
One possibility is lubricating substances used in industrial manufacture to keep products from sticking to forms and such. That’s one reason when you buy re-usable plastic containers from companies like Ziplock and Glad it says to wash them before use - some manufacturing residues can linger on the product. The quantities involved are pretty darn small, I doubt they’re enough to make a full size human sick, but obviously it’s not a good idea to needlessly consume such things.
Which would seem to support my view, stated above, that if anything, refilling and reusing plastic bottles ought to be safer than drinking the original product which has been sealed in newly manufactured bottles and left to sit on the shelf for X months.
BPA is in most plastic-lined steel food cans; it is definitely not in stainless bottles of the type I pointed to.
Well, as long as you keep those bottles you’re reusing clean - I wash mine out, and toss them at the first sign of grottiness.
Just to be safe I drink water from a stainless steel bottle, and the water was dispensed through copper pipes. I think more and more will be found wrong with plastic, especially when it is heated in the microwave or whatnot.
BPA has two major aspects when interacting with human systems. First it is toxic in larger quantities. The levels reached by exposure to lined cans, drinking bottles, etc. don’t generally rise to anywhere near the micrograms per kilogram needed for BPA poisoning. The other aspect of how BPA interacts with humans is that it is a endocrine disruptor, meaning it messes with, or simulates, the signals your body uses to regulate pretty much all of your systems, hormones. Studies of BPA as an endocrine disruptor are showing this second effect to be more far-reaching and be present at much lower concentrations than the toxicity aspect of BPA. Studies of BPA exposure, at or under levels allowed by the FDA for humans, in mice have lead to the following results.
Dose (µg/kg/day) Effects (measured in studies of mice or rats,
descriptions (in quotes) are from Environmental Working Group)[96][97] Study Year
0.025 "Permanent changes to genital tract" 2005[98]
0.025 "Changes in breast tissue that predispose cells to hormones and carcinogens" 2005[99]
1 long-term adverse reproductive and carcinogenic effects 2009[70]
2 "increased prostate weight 30%" 1997[100]
2 "lower bodyweight, increase of anogenital distance in both genders, signs of early puberty and longer estrus." 2002[101]
2.4 "Decline in testicular testosterone" 2004[102]
2.5 "Breast cells predisposed to cancer" 2007[103]
10 "Prostate cells more sensitive to hormones and cancer" 2006[104]
10 "Decreased maternal behaviors" 2002[105]
30 "Reversed the normal sex differences in brain structure and behavior" 2003[106]
50 Adverse neurological effects occur in non-human primates 2008[41]
50 Disrupts ovarian development 2009[71]
Normal concentrations of hormones in humans are very low, but they have powerful effects even at low concentrations. It stands to reason that low concentrations of endocrine disruptors will also have powerful effects.
About a year and a half ago Scientific American tackled this question and had one of the best overviews of the situation with BPA that I’ve seen, from a scientific viewpoint. Basically the science is very clear, but the politics and economics are opposed to the science at the moment.
Enjoy,
Steven