From the Duke University series on chemicals in everyday consumer products,
Fluorotelomers are another class of halogenated compounds with seemingly magical properties. One of those is its lipophobicity — a really great technical term for something that repels oils and fat. If you’ve got a surface that you don’t want to get stained, fluorotelomers are a great solution. And if you’re using paper with fatty, oily foods, a layer of fluorotelomers will keep the paper clean and crisp.
An ideal place for fluorotelomers is a microwave popcorn bag. A coating of that stuff will keep the butter and oils on the popcorn where you want it and not in the bag where you don’t. Ingenious. Except there’s a problem.
Expose fluorotelomers to high temperatures and they break down into PFOAs. So every time you crunch on microwave popcorn you are more than likely munching on a little PFOA. Yum. How much? Well, if you eat just one bag of microwave popcorn per week, it’s estimated that you’ll receive enough PFOA to maintain levels found in the averageWe recommend going back to making popcorn on the stovetop. There are several clever stovetop poppers with a handle to keep the kernels from sticking to the pan and evenly pop the corn. Avoid the chemicals and enjoy your popcorn!
American’s blood. (Further reading here and here [pdf])