I also bought a Dritz mat, there was one in the shrink wrap and another one without..of course I purchased the one that was wrapped!!! Wrong move there! It still stinks, it has been two months now. It has cuts in it now from me using it, nothing like an Olfa mat. Here I thought I was getting a bargain and saving 5 bucks!!!!!!

I left my mat in the garage for about 2 months .. It finally did not stink quite so much. ..but during that time every time I went in the garage .. I thought a skunk had gone off.
I have found the amount of time it needs it how "fresh" it is or how little airing out time it had at the store.

Take back to store you purchased it from.

I threw away my recietpt, I got it at Jo Ann's on sale.

It's offgassing VOCs. It's the same thing as "new car smell" and "new shoe smell." It's from being shrinkwrapped immediately after manufacture; the gasses haven't had a chance to evaporate.

The smell will dissipate, but no amount of washing or deodorizing will speed up the process. If it's at all possible, store it outdoors until the smell abates. You mentioned you live in an apartment; do you have a balcony or porch of some kind? I would worry less about the sun warping the mat than the bombardment of VOCs in your home.

In the future, buy unwrapped mats. :)

Try placing it into a paper/plastic bag and add a good helping of Bi-carb. Leave for a couple of weeks. This worked
for me on books that had been stored for years.

DON'T put the mat in the sun. It WILL warp.

Previous posts about this indicated you just need to give it a few days to air out