I received two types of mats:
- FS Series 2-Layer Diss/Cond Smooth Econo Rubber Work Top Mat Roll, Grey/Black, 24" x 40' x .080This was the big roll. It is not suitable for a direct soldering surface, if you touch an iron to it (390C), it will turn dark brown/black. It won't melt at all so its better than pure PVC, but if you plan on soldering or using hot air put a silicone mat on top of this one to protect it. Seems to discolor around 270-280C.
"The top layer of this mat is composed of nitrile rubber and polyvinyl chloride. The bottom is composed of reclaimed rubber and styrene-butadiene rubber."
- FT Series 2-Layer Diss/Cond Textured Heavy Duty Rubber Worktop Mat Kit with Wrist Strap, Ground Cord and Two Snaps, Grey/Black, 30 x 60 x .080The smell on this one was really bad, takes one or two weeks outside to let it air out. The feel is slightly softer, more flexible. If you touch the soldering iron to it it will discolor but not nearly as bad as the econo mat.
"The top layer of this mat is composed of nitrile rubber and the bottom is composed of natural rubber and styrene-butadiene rubber. "
So check the material when buying if you are looking for temperature resistance.