Well, I spoke about bisphenols in general, rather than bisphenol A in particular. There is testable activity from all currently used members of the family. Observable activity does not, however, automatically translate into a safety problem, but that is WAY too complex a discussion for an internet forum. Buy me a beer sometime and I will explain the technical difference between hazard and risk. (FYI: This distinction is lost on some of the field's academic researchers and is the major substantive difference in the back and forth on this issue between the European Commission, EFSA and USFDA on one hand and the European Parliament on the other.)
Principally, because the bottles we use today are much, much thinner than the ones we used to use for sustainability reasons. Reuse implies aging and misuse like freeze-thawing, which tends to make the plastic brittle. Storage in the heat or sunshine is similarly destructive. And because the beverage is in the bottle, it acts as a structural support of its thin walls. The moment you unscrew the top, however, the walls of the bottle start to bend and the brittle bottle may break, generally an unpleasant experience. Also, some beverages don't respond well to light and heat and the quality becomes poor.
Honestly, I think reusable bottles made from either glass or PET (thick-walled, like the Germans have) is a good idea from an environmental point of view. But then you have to have a collection system which forwards the used bottles in crates back to the factory for processing, as well as a consumer population which doesn't mind buying beverages in externally scuffed, reused bottles. Only some countries have managed to make this work.
Non-reusable, but recyclable glass bottles/jars are actually pretty objectively bad for the environment. Even if you start with recycled glass, the amount of energy required to melt it down and blow a bottle is a significant environmental impact which is only really offset by long-term reuse of that bottle. If you just throw it away in the glass bins like you do here, you'd be better off just buying and recycling the PET plastic ones.
Hi Mrs. WorWoo, this is why good scientists read all of the papers within a field, rather than cherry-picking one or two which defend a hypothesis.
You managed to find the one study which was communicated in the media in 2009, but subsequently 'disproven'. Hint, the water from the glass bottles in this study had as much activity as the PET ones. The authors of this study didn't test the water which was the source of the activity. Most tap and surface waters have measurable levels of estrogen activity in them, some from natural hormones from the wildlife, some from the people, and some from anthropogenic sources (e.g. hormonal birth control). The authors of this study collected the correct data, but came to the wrong conclusions, a fact which was immediately discussed in the papers of others, which is why it is so widely cited. (Sometimes it is better for your scientific career to be incorrect, than correct .) Unfortunately, that less dramatic part of the discussion wasn't widely covered in the media, so no link from abc there.
You can independently verify what I'm saying by going to the pubmed page for that 2009 paper; to the right of the abstract is a field listing all the papers which cite it. Click on the links of those abstracts to get to the corresponding papers. You can read them for yourself and see what they conclude.
I have looked at the list of papers you mentioned (to the right of the abstract). They do not disprove that most plastic products release estrogenic chemicals, PET included - they support it, though some state that alternatives may be available:
"Results: Almost all commercially available plastic products we sampled—independent of the type of resin, product, or retail source—leached chemicals having reliably detectable EA, including those advertised as BPA free. In some cases, BPA-free products released chemicals having more EA than did BPA-containing products.."
i had a soda club once and it almost killed me! always fill the bottle with water to the max, because if you dont... the gas builds up in the bottle and can burst the whole lot. i was lucky i got not hit by metal and plastic parts that were ripped apart. the reason i did it was, that i did not always need 1 litre of bubbly water...just enough to make some fizzy apple drink and the rest i had to pour away. i found it was a waste of water. now i have returned to PET.
You could always store the rest of the litre in the fridge, the fizz lasts a couple of days, that way you have fizz ready to make more apple drink tomorrow.
Not particularly, no. I read widely from the scientific literature and interpret the evidence such as it is. This does include industry-funded studies (particularly the standardized safety ones they are required to do by law), though not exclusively.
If it seems a particularly important study, i.e. one which is useful for establishing the toxicological point of departure, then I will try to get my hands on the raw data tables and assess from that. This systematic review/weight-of-evidence assessment process is pretty much the same as the one that a regulatory authority uses.
The large portion of the internet devoted to conspiracy theories and guilt-tripping parents into believing that they are parenting their kids wrong, isn't really included in a weight-of-evidence assessment, though; as it is not scientific data.
I think that it is also important to note that ALL studies are funded and conducted by groups with a financial interest in the outcome. Government grant funding levels are really tight; part of every proposal is to solve a perceived problem. The greater the controversy surrounding the problem, the more likely it is to get funded. Non-governmental organizations have a particular stance they wish to defend and fund from member contributions. The more publicly controversial, the more people will contribute. And, yes, industry generally spends the the large sums on products they actually plan to market. Essentially, all scientific studies are a very inefficient and expensive way to convert money into paper/PDF files, conducted by people trained to be objective, but funded subjectively.
So the 'vested interest' model suggested above is ultimately a really poor way of assessing scientific data. What usually works well is a large number of knowledgable experts in a field trying to remain as objective as possible while thinking critically about each other's work over long periods of time. We call this peer-review. Over multiple observations under many different conditions, the evidence becomes clear and the discussion is resolved and becomes part of the established body of knowledge of the field.
Perhaps though, as the topic has now veered widely from the original question of whether PET bottles for Sodastream-type systems are safe, the original question can be considered satisfactorily answered? If so, then I will stop following this thread. The OP can PM me to ask for more information if she/he wants further information.
It actually is more expensive than the cheaper bottled waters. You pay about 18chf for a CO2 cartridge that will make 60L fizzy water at most. Less if you like it more fizzy than average. Prix garantie water is 25 rappen/1.5L which is cheaper. Still worth it for not having to carry water from the shop and the environmental aspect. Thanks Tox Rat for your comments, i think plastics rock. Don’t forget to calculate in transport costs for heavy glass bottles if you make an environmental impact calculation. On that topic did you know you have to use a organic cotton shopping bag 20.000 times for it to have the same overall environmental impact as a plastic bag you reuse once as a bin bag? A paper bag 40 times. Which makes it bizarre some countries are banning plastic bags at the moment!
I don't really like SodaStream (several reasons, including the business model/pricing mentioned here, and the build quality of the hardware), so I've been pining for something self-made .
If I can figure out where to order all the stuff at a reasonable price, I'm tempted to try. If I had an ounce of handyman ability, I'd make a pretty kitchen counter installation, but... yeah, that's not happening. Maybe in the cellar.
We are on our third soda stream machine, but all our friends have them too and have no issues. If you don't want plastic bottles, then get the one for glass bottles.