Q.Garden setup
I stumbled upon these matts a few years ago to hold down the end of my garden cover. What i noticed is that they keep the weeds at bay. So this year i got 6 more to go all around the garden. What i just worried about is run off from these mats because they are made of petroleum products. They are made of rubber. Do you think that’s a problem? Will i get harmful runoff from these mats into the garden or am i being overly worried?
Thank you
Dave

I don't think that there is a contamination issue. I think your solution is quite smart!
I use a few of these squares myself on my greenhouse floor to lessen the strain of standing!