1,1'-Biphenyl, 2,2'-dichloro- (9CI) 13029-08-8 2,2'-DICHLORO-1,1'-BIPHENYL 2,2'-Dichlorbiphenyl [German] 2,2'-Dichlorobiphenyl 2,2'-Dichlorodiphenyl Biphenyl, 2,2'-dichloro- NSC 59902 PCB 4 o,o'-Dichlorobiphenyl