Chemical reactivity-absorption, retention, metabolism, and elimination of hexachlorocyclopentadiene

Hexachlorocyclopentadiene is eliminated from the body efficiently by urinary excretion. Although direct evidence is not available, it appears that expiration may be another important route of elimination. Of the administered dose 9% is excreted in the bile in 1 hr, approximately equal to the amount of fecal excretion in 7 days, suggesting enterohepatic circulation. After a single dose, HCPD decays from the blood biexponentially with a terminal phase half-life of 60 min. Of the tissues analyzed kidney, followed by liver, concentrate HCPD 1 hr or 7 days after exposure to any significant extent. Subcellularly, HCPD is predominantly associated with cytosol fractions of both kidney as well as liver, observations consistent with rapid elimination of HCPD after a single exposure. Preexposure to HCPD (50 mg/kg-day for 3 days) resulted in unaltered blood decay curves and biliary excretion, but increased the concentration in the kidneys after a single subsequent challenge.