We are surrounded by carpet, paint, wall board, various types of plastic and composite materials, air containing vehicle exhaust, etc, etc, etc. Relative to that, I'd think effects from ESD mats are negligible. Only way to be sure is to purchase one, send it to lab, and have it analyzed. Yes, it'll be quite costly, but anything else is just a conjecture. Again, Amazon sellers will often switch products. Each purchase will have to go through the process.