No studies are available on the effects of human exposure to endrin by the inhalation or dermal routes. Acute human poisoning from endrincontaminated food results in jerking of legs, tonicclonic contractions, convulsions and sudden collapse, and death. Data in animals exposed via inhalation, oral, and dermal routes confirm that endrin can affect the nervous system, causing clinical signs including tremors and convulsions. Decreases in body weight gain and histopathologic damage to liver and kidneys have been reported in animals following acute oral exposure.
Data was not found to be sufficient to derive oral or inhalation acuteduration MRLs.
The World Health Organization has not listed endrin in WHO Acute Hazard Rankings because as an active ingredient is believed to be obsolete or discontinued for use as a pesticide.
Studies performed by the U.S. EPA placed endrin formulations in Acute Toxicity Rankings in a Category 1, Highly Toxic (Table below).
No studies are available on the adverse health effects from intermediateduration exposure in humans by any route. Studies in animals indicate that exposure to endrin via inhalation can be lethal and causes effects on the nervous and respiratory systems, the liver, the brain, adrenals, and kidneys. Since systemic effects were observed at levels which caused death, data are not sufficient to derive an intermediateduration inhalation MRL. Animal studies also demonstrate that oral intermediateduration exposure can lead to death in several species and following dermal exposure endrin was lethal in rabbits.
Studies of humans chronically exposed to endrin in the occupational setting indicate target tissues similar to those for acute exposure. Quantitative exposure data are lacking in humans, but data in animals are sufficient to derive NOAELs and LOAELs for neurologic, hepatic, renal, and cardiovascular effects in dogs. A chronic MRL was based on a NOAEL for convulsions in dogs administered endrin in the feed and it is anticipated that the chronic MRL should be protective for any exposure of acute or intermediate duration. No studies are available in humans or animals chronically exposed via dermal exposure.