Acute inhalation, oral, and dermal exposure data in humans have identified neurological, gastrointestinal, hematological, and respiratory effects, and jaundice as the presenting symptoms in persons exposed to high doses. High level oral exposure to chlordane may be lethal. The data suggests that the target organs for acute exposure in humans are the central nervous system and live. Specific levels associated with effects in these organs in acutely exposed humans are not known.
Acute inhalation data in rats have identified a level associated with mortality. Acute oral and dermal exposure data in animals have identified LD50 values and levels associated with mortality in rats, hamsters, and mice. Acute oral data also have identified the liver and the central nervous syste
m as target organs in rats. The animal data confirmed the target organs in humans, and, based on similar target organs and metabolic pathways, the rat appears to be an appropriate model for toxicity in humans.
An acute oral MRL of 0.001 mg/kg/day was derived from a LOAEL of 1 mg/kg/day for developmental effects in the offspring of mice exposed to chlordane in the diet during the third trimester of pregnancy. The pharmacokinetic data in animals, which indicate that absorption occurs following exposure by any route, and the human effects data indicate that the central nervous system and liver would be the target organs of dermal exposure
The World Health Organization has classified hexachlorobenzene as Class II moderately hazardous.
Studies performed by the U.S. EPA placed chlordane formulations in Acute Toxicity Rankings in a Category 2 and 3, Slightly to Moderately Toxic (Table below).
|LD50||Domestic animals (goat, sheep)||50||mg/m3|
No data were located for human oral or dermal intermediate duration exposure.
Intermediateduration inhalation exposure data in rats, mice, and monkeys have identified the lungs, hematological system, liver, central nervous system, thyroid, and possibly the thymus in female rats, as the target organs.
Intermediateduration oral studies have identified levels in rats, mice, and rabbits associated with death, and identified the liver, central nervous system, and developing immune system as target organs.
Intermediateduration dermal exposure induces convulsions and liver necrosis in mice and hyperkeratosis of the skin of guinea pigs.
termediateduration inhalation MRL of 0.0002 mg/m3 was derived based on a NOAEL for hepatic effects in rats exposed to chlordane intermittently for 90 days. An intermediate duration oral MRL of 0.0006 mg/kg/day was derived based on a NOAEL of 0.055 mg/kg/day for hepatic effects in rats given chlordane in the diet for 30 months.
Chronic toxicity inhalation data include two case report studies of blood dyscrasia, and several studies of humans living in chlordanetreated homes or exposed to chlordane during its manufacture or during its use as a pesticide. Dermatitis, migraine headaches, unspecified skin neoplasms, and unspecified ovarian and uterine disease have been associated with chronic inhalation exposure to chlordane. A chronicduration inhalation MRL of 0.00002 mg/m3 was derived from the NOAEL for hepatic effects in rats exposed to chlordane intermittently for 90 days. Elevated serum levels of hepatic enzymes associated with liver damage were found in pesticide applicators.
No studies of chronic oral exposure to chlordane were located for humans. Chronicduration dermal data in humans are limited to a report of seizures in a nursery owner who handled soil containing chlordane.
Chronicduration animal exposure data, located only for oral exposure, have identified levels in rats and mice associated with reduced survival, and identify the liver and central nervous system as target organs. A chronicduration oral MRL of 0.0006 mg/kg/day was derived based on the NOAEL for hepatic effects in rats given chlordane in the diet for 30 months. Chlordane induced liver tumors in mice, and chlordane has not been sufficiently studied for reproductive effects.
No chronic inhalation studies of chlordane in animals were located.