1,1'-Biphenyl, 2,2',3,3',4,6'-hexachloro- 2,2',3,3',4,6'-Hexachloro-1,1'-biphenyl 2,2',3,3',4,6'-Hexachlorobiphenyl 2,2',3,3',4,6-HEXACHLOROBIPHENYL 38380-05-1 GPCB 132 PCB 132