great question mrd. i've been wondering the same thing about rubber products in general. what do we look for regarding rubber/plastic products to determine if off-gassing is going to be a problem? i was gonna throw a rubber mat in a room last week, but the smell of the rubber made me stop and wonder if it might be a problem.
for some products (like, i would assume, a pond liner), we can review the msds sheets . . . so when that's the case, what should we look for on them to know if it's a problem?