I bought and returned 4 24x36" Omnigrid cutting mats from two different JoAnn stores within 6 months. They all smelled so bad I could not keep them in the house. When I returned each of them at separate times they smelled up my car so I had to drive with all windows down. I about gave up on them.
Then I was in my local Ben Franklin store and they had one so I smelled it there, not a scent. Bought it, brought it home, no odor whatsoever. Funny thing.