Officers received a report of a single-vehicle crash at about 5:15 a.m. that left a pickup truck carrying pest control chemicals lying on its side and blocking east and westbound lanes of Highway 12 near Red Top Road in Solano County, CHP officer Ralph Caggiano said.
The driver was not injured in the crash, Caggiano said, but an unspecified amount of a pesticide the truck was carrying was reported to be spreading across the roadway.
Traffic attempting to access eastbound Highway 12 in Napa County is being turned away at an interchange with state Highway 29, according to the CHP.
Traffic attempting to access westbound Highway 12 in Solano County is being turned away at Interstate Highway 80.
A Solano County interagency hazardous materials team was called at about 5:20 a.m.
Drivers in Napa County are being rerouted to an alternate thoroughfare on state Highway 37, Caggiano said.
A Sig-alert was issued at 5:36 a.m.