Two northbound lanes were closed near Avenida Pico since the crash was reported at about 10 p.m. Sunday. Officials said a big rig struck a guardrail and overturned. No other vehicles were involved in the incident.
Investigators said at least 150 gallons of diesel fuel possibly went down a storm drain while loads of tomatoes and green peppers scattered across lanes.
The driver of the big rig was not injured, and the cause of the crash was under investigation, officials said.
Hazmat crews and officials from an Orange County health department, U.S. Coast Guard the California Department of Fish and Wildlife responded to the scene to help minimize any impact from the spill.
Crews at the scene were also attempting to get the big rig on its wheels and clean up the vegetables.
The closure was expected to last through at least 9 a.m.