Specific Substances: Chlorpyrifos (Dursban)
Nomination Date: 03/21/1996
Nominator: Workplace Health Services
Rationale: Microencapsulated chlorpyrifos is designed to cause the chemical to stick to surfaces and last longer as a surface toxicant for insects. The nominator hypothesizes that the nervous system of humans exposed by inhalation to the microencapsulated chemical may develop serious disruption of normal acetylcholine-mediated synaptic transmission. The chemical may be delivered to the olfactory nuclei by direct olfactory nerve axonal transport. From there the cholinergic effects of the toxin could act directly on the cholinergic tracts from the forebrain and the cholinergic radiations to the nuclei within the limbic system.
NTP Principles: not specified