Maybe acrylamide? It is often found in potato chips and other cooked, starchy foods. (Though, I imagine you would have to eat an absurd amount of potato chips for this to be a concern.)

@Mark: Is there any limits specified for consumption beyond which it can be risk for cancer development?

This document looks like it might be a good start answering your questions about acrylamide in food. I'd check the FDA websites and resources for any specific numbers/limits/regulations you are interested in. I would also check an MSDS for acrylamide and look up the toxicology information, if I were you.

http://www.fda.gov/downloads/Food/FoodborneIllnessContaminants/ChemicalContaminants/UCM194483.pdf

@Mark: Thanks a lot for sharing such valuable information.