I haven't been able to find anything that states that EPDM cannot be made ISO compliant, but niether have I found anyone selling it. I did find a lot of articles that were made with EPDM and another material, possibly to combine it's mechanical properties with the biocompatibility of the second material.
Another reason it's hard to find may be the recent focus on testing materials in finished condition. Since these material go through many manufacturing steps (especially if they're one of the first components), agencies want to see test data on materials that have already been cured, cleaned, baked, handled, and sterilized. I've spoken to several suppliers who say they don't do materials testing anymore because their customers are just going to have to do it again to sell their devices. The best they offer is to tell me that they're "sure it will pass." EPDM may be suffering from this issue...
