Propachlor

Abstract

Evaluates the risks to human health and the environment posed by propachlor, a re-emergence and early post-emergence herbicide in use since 1965. Derived from acetanilide, propachlor is used in agriculture to control annual grasses and some broad-leaved weeds in several crops, including corn, sorghum, pumpkins, flax and flowers. A section devoted to the environmental behaviour of propachlor cites rapid degradation by microorganisms in soil and water, and concludes that this chemical does not bioconcentrate or biomagnify. Studies of metabolic fate in different mammalian species point to rapid elimination of propachlor and its metabolites. The remaining sections evaluate findings from toxicological investigations in experimental animals and, for humans, the limited data available from cases of contact and allergic dermatitis reported in farmers and production workers exposed to propachlor. For experimental animals, the liver and kidneys are identified as the target organs. For human exposures, the report found no evidence of symptoms or diseases reported for either occupationally exposed workers or the general population, with the exception of scattered reports of dermatitis in workers. On the basis of these evaluations, the report concludes that, under conditions of normal use, exposure of the general population is unlikely. For occupationally exposed workers, the report recommends the use of adequate safety and hygienic precautions to protect the skin, eyes, and respiratory tract. Though propachlor is judged to pose a low hazard to birds, earthworms, and honey-bees, evidence indicates high toxicity to some aquatic organisms, supporting the conclusion that direct contamination of water courses should be avoided