1. Phenylenediamine may refer to: o-Phenylenediamine or OPD, a chemical compound C6H4(NH2)2 m-Phenylenediamine or MPD, a chemical compound C6H4(NH2)2 p-Phenylenediamine or PPD, a chemical compound C6H4(NH2)2 == Related compounds == N,N-Dimethyl-p-phenylenediamine or DMPD N,N,N′,N′-Tetramethyl-p-phenylenediamine or TMPD, used in microbiology N,N-Diethyl-p-phenylenediamine or DPD from wikipedia.org