I bought an Olfa mat, and oh my gosh, it smelled SOOOO bad. We had left it sitting in the living room, and then I started smelling this awful chemical/burning smell. We thought some wires in the walls were on fire or something -- we were actually on the phone with our electrician, talking to him about it, when I finally realized what was causing the nasty smell. Felt pretty stupid, that's for sure.