Octachlorodibenzo-p-dioxin (OCDD) is an environmental contaminant with no acute toxicity when administered. In rats, the systemic elimination half-life of Octachlorodibenzo-p-dioxin (50 μg/kg intravenously or 50-5000 μg/kg orally) is 3-5 months. It can accumulate and concentrate in the liver and adipose tissue after low-dose, repeated exposure. Repeated dosing of Octachlorodibenzo-p-dioxin leads to increased activity of 7-ethoxyresorufin-O-deethylase (7-EROD) and elevated total cytochrome P-450 levels.