Synonyms: 1,3-Benzenediol,4-(2-pyridinylazo)- (9CI);Resorcinol, 4-(2-pyridylazo)- (6CI,8CI);1,3-Dihydroxy-4-(2'-pyridylazo)benzene;1-(2-Pyridylazo)-2,4-dihydroxybenzene;4-(2-Pyridinylazo)-1,3-benzenediol;4-(2-Pyridinylazo)-1,3-dihydroxybenzene;4-(2-Pyridinylazo)resorcinol;4-(2-Pyridylazo)-1,3-benzenediol;PAR;PAR (resorcinol derivative);