I took the sides of the cases off last night, smelled closely, still very fresh after a couple years. Coincidentally, my headache got worse last night after smelling them. I think it's mostly odorless hydrocarbons though. All in all, 2 XL cases and the mini ITX case, and it's several square feet of asphalt that's been spewing gasses into the room until equilibrium is reached. Easily done given that I have about 200 CFM in each big case and 100CFM or so through the other. 500CFM of air passed sheets of asphalt into my living quarters. WTH WERE YOU THINKING FRACTAL. Now I have to rip those things out of my cases. I thought it was awesome when I got them, but if someone would have told me what it was, I would have never bought them. Now I have COPD symptoms. Thanks. Jerks.