Para-Phenylenediamine (CAS No. 106-50-3) was evaluated as cause for methemoglobinuria in sets of 2 each beagle dogs fed single gavage doses of 1.0, 3.0 and 10.0 mg/kg bodyweight. All dogs exhibited lacrimation, while 10.0 mg/kg dosed dogs showed red and swollen eyes persisting in one dog at 24-hour post-gavage observation. Slight redness was also noted in the eyes of 3.0 mg/kg dogs, but all such signs were resolved by 24 hours after treatment. Cyanosis and anoxia were not noted in any dog of any treatment level. Likewise, methemoglobinemia was not induced at levels producing pharmacotoxic effects in beagle dogs.