Swiss-made SIGG water bottles have long been touted as the safe alterative to disposable plastic bottles, but then controversy erupted.

Plastic bottles are bad for the environment and known to leach chemicals into drinking water. For eco-conscious consumers, opting for SIGG was an uncontested purchase.

More recently SIGG released a statement about its eco-friendly bottles, confessing to a major design flaw: The resin liner inside each bottle contains bisphenol-A (BPA), a hormone disruptor and chemical that is often tied to cancer.

Does your SIGG water bottle contain BPA?

According to SIGG, if you purchased your water bottle after August 2008, then you're in the clear, because they started using a BPA-free EcoCare liner. If you're still unsure, they have a liner guide to help you determine which model you have.

Just how bad is bisphenol-A and where is it lurking?

The Food and Drug Administration is still testing the effects of this chemical, but is not recommending that anyone discontinue using products that contain BPA. For now, FDA-approved products containing BPA, such as canned foods and plastic bottles, are safe.

Science News reported that traces of BPA have also been found in cash register receipts. Another reason to wash our hands!

What was SIGG's response?

On October 1st, SIGG issued a statement highlighting the fact that they never claimed to be BPA-free, just 100 percent leach-free. SIGG is offering a voluntary exchange program that runs through the end of October 2009. They will exchange your old bottle for a new one, but you'll have to cover shipping costs. To find out more about the exchange program, go to mysigg.com.

In some cities, grocers like Whole Foods are also hosting their own exchange programs for SIGG water bottles. Check with your local store to find out if they're offering this option.