What is Dursban?
Dursban is a trade name for chlorpyrifos, a broad-spectrum insecticide used to kill a wide variety of insects. Classified as an organophosphate, chlorpyrifos is a contact poison that interferes with an enzyme essential for the proper working of the nervous system in humans and insects. Chlorpyrifos is relatively insoluble in water, binds strongly to soil particles, and is persistent in the environment. It is absorbed in human and animal body fat up to 40 days after a single exposure.
Chlorpyrifos is available in emulsifiable concentrate, dust, pellet, spray, granules, and wettable powder. It was registered for direct use on certain animals, farms and farm buildings, schools, nurseries, hospitals, restaurants, commercialbuildings, and domestic buildings. However, it was withdrawn by the manufacturer for indoor applications and from the direct application pet care product market. Chlorpyrifos is routinely used by homeowners and pest control companies for outdoor insect treatments and yard turf grass applications, and is used to saturate the soil as a termite preventative just prior to pouring the concrete foundation. The EPA requires a 24-hour reentry interval before entering crop areas treated with emulsifiable and wettable formulations of chlorpyrifos, unless protective clothing is worn. Indoor air guidelines for chlorpyrifos have been exceeded during indoor flea applications and reached borderline evacuation levels in many homes which have been treated for termites.