Toxic Aroclor 1221 Mixture Identified: Implications for Environmental Health.
The major components of a commercial polychlorinated biphenyl mixture, Aroclor 1221, have been identified as biphenyl, 2-chlorobiphenyl, 4-chlorobiphenyl, 2,2′-dichlorobiphenyl, 2,4-dichlorobiphenyl, 2,4′-dichlorobiphenyl, and 4,4′-dichlorobiphenyl.