Also Called: 2,2’,3,3’,4,5,5’-heptachlorobiphenyl;2,2',3,3',4,5,5'-Heptachlorobiphenyl;PCB 172;Polychlorinated biphenyls (PCBs);1,1'-Biphenyl, 2,2',3,3',4,5,5'-heptachloro-;1,2,3,4-tetrachloro-5-(2,3,5-trichlorophenyl)benzene;2,2',3,3',4,5,5'-Heptachlorobiphenyl (PCB 172)