Acute toxicity was evaluated in groups of 3 male CRCD rats receiving single doses of o-dichlorobenzene by subcutaneous intra-scapular injection at levels of 0.04, 0.2, 1.0, 5.0, 10.0, 19.0, 37.0 or 74.0 g/kg body weight. Mortality was observed in all animals receiving test article at dose levels of 10 mg/kg or higher (within 4 days of dosing), and the LD50 was reported to be between 5.0 and 10.0 g/kg. Clinical observations included yellow stained anogenital areas, passiveness, slow deep respiration, loss of righting reflex, ataxia, red stained eyes, salivation, lethargy, lacrimation, prostration, tremors, moribund, ptosis and clonic convulsions. Gross necropsy of decedents revealed slight to moderately red lungs, while no visible lesions or gross changes were observed in survivors at 14 days. Document includes: Acute Toxicity Report. O-dichlorobenzene Myelotoxicity & Cytogenetic Study in Rats. O-dichlorobenzene Microbial Mutagen Test. Mutagenicity Evaluation of O-dichlorobenzene Final Report. Mutagenicity Evaluation of Monochlorobenzene Final Report.