The mat will break up after a year or so of use on a low to medium pile apartment quality carpet. The smell of plastic was so bad that the replacement is still in the garage. Chemicals from the mat may cause some pigments in engraved documents to sulphurize causing oranges and reds to turn black. It may be possible to wash off the worst of the toxic chemicals with a 1:4 mix of vinegar and water.
Just bought this and at [$] I couldn't see spending more on one of these. The last one lasted about 2 years before it became hard and brittle and started to crack and splinter (jabbed my feet several times). Hope this one lasts longer. The more expensive ones seem thicker so if you have shag or deep pile rug might be a better investment.