In 1999, the U.S. EPA released two interpretive memos that threatened to shut down nearly all recycling of automotive shredder residue.
The memos indicated that since plastics and foam can potentially contain polychlorinated biphenyls, or PCBs, any reuse of those plastics and foams would be prohibited under the Toxic Substances Control Act unless recyclers could prove that they processed absolutely no PCBs. This rationale applied not only to ASR but to any material that might contain PCBs, such as plastics that could contain PCB-infused plasticizers and stabilizers. This battle over potential PCB contamination in ASR would continue to rage for more than a decade until ISRI and EPA reached a positive resolution in 2013. (More on that victory later.)