DEET (N,N-diethyltoluamide) does not affect sperm number, viability and head morphology in male rats treated dermally

DEET (N,N-Diethyltoluamide) was applied dermally to groups of 80 Sprague Dawley rats 5 days/week for 9 weeks (63 days), at three dose levels, (100, 300, and 1000 mg/kg). The undiluted material was applied with micropipettes to shaved patches. There was no run off and the material wet out onto the skin. Dose levels were calculated based on mean weights and adjusted weekly by reweighing half the animals in each group and calculating a mean body weight. Animals were scheduled for kill at three times; days 36-37, 65-66 and 95-96 after initiation of treatment. Data collected at each kill included sperm count, viability as assessed by ATP levels and morphology; testes histopathology (control and high-dose groups only) and body and organ weights (liver, kidneys and testes). DEET, when applied dermally, did not alter sperm count, sperm morphology, sperm viability, body weight or food consumption at any dose level tested.