safe to use rubber roof liner as grow bed liner

We have been given 150ft of rubber roof liner for redoing the roof on rvs. Is it safe to use this as a pond liner in grow beds in an aquaponics system? We are breaking ground for a large greenhouse to set up a semi commercial aquaponics and it would be a big cost savings if we could use this rubber liner. Anyone have any experience in this?

I would call up the manufacturer and ask if the material is potable water safe? It doesn't have to be rated by NSF (the rating costs money) but the material should be of the kind that would pass the test if they took it.

I'm guessing the answer is no, but it doesn't hurt to check.