If you're anything like me, and have tried reducing the amount of plastic (ie BPA and pthalates) with which your children come into contact, you've probably bought a Sigg at one time or another.
Recently, the CEO of Sigg announced that some of their previously manufactured bottle liners did contain BPA, a chemical used in polycarbonate plastic food and beverage containers and appears to cause health problems in animal studies. Though the company claims that the bottles do not leach and are safe, they are offering an exchange program.
Check your bottles to see if you have the old liners with BPA, if you do send them to the company (they provide a label but you pay for shipping) and they email you a code to buy new bottles with the more recent (and presumably BPA free) ecoliner.
I sent mine off this week.
Go here for details.