PCB NO 172;2,2',3,3',4,5,5'-HEPTACB UNLABELED CERTIFIED STANDARD;1,1'-Biphenyl, 2,2',3,3',4',5,5'-heptachloro;2,2',3,3',4,5,5'-Heptachloro-1,1'-biphenyl;PCB 172;2,2',3,3',4,5,5'-HEPTACHLOROBIPHENYL;1,2,3,4-tetrachloro-5-(2,3,5-trichlorophenyl)benzene;PCB172 in Cyclohexane