I wrote about my water bottles some months ago. And I'd written a draft blog article that I never posted about water bottles. And then I read the news that Sigg water bottles, which everybody's been buying big-time because they don't contain BPA, contain BPA.
So, look at the comment I wrote on Real Green Girl's blog entry about Klean Kanteen vs. Sigg some months ago:
The more I look at it, the less I trust any of them. Assuming that Sigg (and other "lined Aluminum") makers are using the standard beverage epoxy lining, BPA is an ingredient. That's documented.
Now, there are linings available that do not contain BPA. Laken claims to use a BPA-free lining.
You want to know what I bet is going on? I've got two Sigg bottles, one newer and one older, and the lining is different colors between them. I'm betting that they've gone through some number of different liners over the years so they'd like to avoid the issue altogether because at some point they may have used an EPA-containing epoxy.
It turns out that I'm right. The older Sigg bottle ("mine") has the old lining and comes at a slight risk of BPA contamination. The newer Sigg bottle ("my wife's") has the new lining and is seemingly as safe as the Laken bottle I use regularly.
Now, there's an important test one must follow with all bottles. This isn't scientific or anything. Fill the bottle with water, stick it in the fridge overnight, take it with you all day, and then take a swig in the evening and compare it to how the water tastes from your tap. Now, I may be more sensitive to chemical taste than others and it's probably genetic, because my mom always comments on things having a plastic taste, too. But if you are going on a long ride and your water tastes bad, you won't be as willing to drink it and might get dehydrated. And you might be getting stuff that's actually toxic.
I hate purchasing water in the form of plastic bottles. Most of those, as a design requirement, have no taste and are generally made out of Polyethylene terephthalate (PET a.k.a. number 1 plastic) and are not really designed for re-use, which is why you don't see anybody marketing reusable PET bottles. And if you go into the store and buy water, it's expensive and bad for the environment.
I have a collection of plastic bike bottles, most of which I got for free at various points. Most of them are Low Density Polyethylene (LDPE, a.k.a. number 4 plastic) and they all end up tasting like plastic after a bit.
My Klean Kanteen bottle tastes slightly metallic, although it's gotten better. Klean Kanteen is made out of Type 304 Stainless Steel (a.k.a. 18/8) which is listed as a food-grade material. It's the same stuff pots and pans are made out of. Brewer's Vats and surgical tools tend to use Type 316, which is a little more resistant to corrosion (At least at one point, Klean Kanteen claimed that they were using the same stuff as brewer's vats, which is only grossly true in that 304 and 316 are similar alloys) If you talk to winemakers, they tend to not keep their wine in stainless steel containers for too long, because it does change the taste.
The problem is that whatever's leaching out of the stainless steel, it's either nickel or chromium. Neither one is generally harmful, but both can be troublesome because you can develop allergic reactions to them and if you get enough of either one, it's toxic. Thus, in Europe, they are starting to regulate the nickel content of jewelery and jeans buttons and stuff.
It also turns out that, despite people implicitly trusting Aluminum bottles, there's some bad stuff going on there. See, the most popular coating for the inside of an aluminum bottle is an epoxy containing BPA... The same BPA that caused everybody to throw out their polycarbonate. There was also the case of some of the off-brand aluminum bottles that contained lead in the paint.
I can understand why Sigg was playing the "it's not a plastic" game with the plastic liner, because people are buying the metal bottles specifically because they aren't plastic. That's simple marketing. But Sigg is very likely going to suffer some consequences for playing the BPA game for so long. I'm sure that the people running Sigg were thinking they were doing the right thing and each step down the road seemed logical. It's just that everything must seem logical in retrospect. That's what's going to really screw them up now. They won't be seen as a trusted brand name anymore.
I'm pretty sure that people are tampering with things that we really don't understand here. You can run a BPA-free aluminum liner through a test for BPA leaching and decide that it must therefore be safe, but there might be something else in the liner that can leach into the drink and cause harm. You might claim that the stainless steel is better, but I can taste something in my stainless steel bottle. Even plastics that use BPA as part of the formula aren't necessarily a danger if the leaching is controlled to a sufficient margin beneath the dangerous level. Except that we really don't know the dangerous level of BPA.
I trust glass bottles and glazed ceramic bottles, but I don't think that either of those is appropriate for use on a bicycle given the risk of dropping the bottle and the weight.
Pretty much, any long-term food storage container may turn out to be just as dangerous as the Radium Ore Revigator. Me? I guarantee that within a few years, there will be some reason why you will look at at least some subset of the stainless steel containers and wonder what the hell we were all thinking.