The Ventura County and Oxnard fire departments responded to the fire in the 3400 block of Sturgis Road about 1:15 p.m. Officials said they believe the fire started on or near an 18-wheel tractor trailer parked at an agricultural storage facility.
Haz-Mat crews also responded to the swelling fire to assess the toxicity of the smoke. Officials said nearby residents were not in danger and evacuations were not expected to take place, but were told to stay away as chemicals went up in smoke.
"We sent hazardous materials teams down wind to start monitoring the level of smoke that appeared to be there but also using air monitors to see if there were any problems," Ventura County Fire Capt. Ron Oatman said. "There were no immediate problems so we didn't cause evacuations."
Fire crews also planned to be at the scene for several more hours because of environmental health concerns. The fire was battled well into Sunday night. They were expected to continue through the early Monday morning hours.
Oatman said an environmental agency would be in charge of the clean up effort.
According to California Highway Patrol, dispatchers received dozens of phone calls from people who saw the fire.
No injuries were reported.
Officials with the Camarillo Airport, which is just east of the blaze, said its tower ceased operations for a short time to assess the situation and ensure the smoke was not toxic. They said everything resumed back to normal at 3:10 p.m.
Pilots were able to take off and land by communicating with each other.