New Type Energy||Renewable Energy

How safe is your reusable water bottle? That's a question many consumers are asking thanks to a recent announcement from Sigg, the manufacturer of trendy aluminum water bottles.

Some consumers switched to the brightly colored metal bottles in an effort to avoid bisphenol-A (BPA), a chemical that interferes with the female hormone estrogen. The controversial chemical has been linked to a long list of health concerns including early onset of puberty, neurotoxicity, and some cancers.

BPA can leach from polycarbonate plastic bottles when it comes into contact with hot liquids and from regular wear and tear. Parents and other concerned consumers thought they were doing a good thing for their family's health and the planet's by choosing metal over plastic.

However, all metal bottles are not created equally. Aluminum bottles typically have epoxy liners, which may contain BPA and other unwanted chemicals. In the past, Sigg would not reveal the ingredients in its liners, claiming that it was "proprietary."

Now, the company admits that the epoxy liners in its bottles used to contain trace amounts of BPA. Sigg says it switched to a new "EcoCare" liner in August 2008, but angry consumers wonder why the company wasn't upfront about the fact that BPA was in its liners.

Sigg says its old bottles didn't leach any BPA. But, how safe are they? "It is possible that very low levels of BPA will leach from the bottle, especially when something hot or acidic is placed in there," says Sarah Janssen, a staff scientist the Natural Resources Defense Council. "As the bottle ages and the resin begins to break down, there will be more leaching. It's the same process as with any other BPA containing container."
What can you do with old Sigg bottles?

If you own a Sigg bottle, the first thing you should do is check to see if you have an old liner or a new one. Even if you bought it after August 2008, you still may have an older bottle that was shipped to the store before the company made the switch. The former lining has a shiny copper bronze finish. The EcoCare liner has a dull yellow coating.

If you have an old liner, then you can trade in your old bottle for a new one. Sigg's voluntary exchange program is available through October 31, 2009. You can pay to have your bottles shipped back to Sigg, or check to see if a local retailer will take it back.

You'll have to decide for yourself if you want to support a company that wasn't completely transparent in the first place.

There's also no guarantee that Sigg's new epoxy liner is completely safe. “Just because a bottle is labeled ‘BPA-free’ there is no guarantee that another toxic chemical wasn’t used as the replacement,” says Janssen.
What kind of water bottles should you look for?

Stainless steel is your best bet if you're in the market for a new reusable bottle or just want to choose the safest option around. "I would recommend going with a stainless steel bottle and avoiding any questions about what the new chemical is," says Janssen.

In general, all aluminum bottles have epoxy linings and just because Sigg has changed its lining doesn't mean other manufacturers have changed theirs. "Consumers should be wary of buying any aluminum water bottle as many are still made with an epoxy resin lining that contains BPA and can leach significant levels depending on the quality of the product," says Janssen.

Luckily there are plenty of safe choices for consumers. Kleen Kanteen, ThinkSport, and Nalgene all sell stainless steel water bottles that are BPA-free and, most importantly, don't have any liners (so there aren't any potentially dangerous secret ingredients to worry about).

For small children, there's a growing array of "sippy cups" made from stainless steel. They're less expensive than Sigg's Kids Bottles, but pricier (yet more durable) than plastic versions. Learn more about buying safe baby bottles.