1,1'-Biphenyl, 2,2',5,5'-tetrachloro- 2,2',5,5'-TCB 2,2',5,5'-TETRACHLOROBIPHENYL 2,3',5,6'-Tetrachlorobiphenyl 2,5,2',5'-Tetrachlorobiphenyl 35693-99-3 4-05-00-01818 (Beilstein Handbook Reference) BRN 2053828 CCRIS 6155 PCB 52 TCBP