13-Week Inhalation Toxicity Study of Dimethylformamide (DMF) in Cynomolgus Monkeys

This study was conducted to assess the subchronic inhalation toxicity of dimethylformamide (DMF) in the cynomolgus mon-key. Particular attention was paid to the liver since DMF has been shown to produce liver damage in rodents, dogs, and hu-mans. Groups of three cynomolgus monkeys/sex/group received whole-body exposures for 6 hr/day, 5 days/week for 13 weeks to 0,30,100, or 500 ppm DMF. Evaluations for toxicity included body and organ weights, clinical observations, hematology, serum chemistry, urinalysis, and gross and microscopic examinations. Clinical laboratory evaluations were conducted twice prior to the start of the study at exposure weeks 2, 4, 8, and 12 and at necropsy. Semen, collected from male monkeys three times prior to the start of the study and weekly during the course of the study, was analyzed for sample volume, sperm count, motility, and morphology. In addition, daily vaginal swabs were obtaine