Nearly 40 people were taken to hospitals for decontamination and homes and businesses for a mile around were evacuated after a mysterious chemical mixture burst into flames at a Southern California waste facility.
The flames and danger had mostly eased late Tuesday, Ventura County fire officials said.
A vacuum truck exploded into flames about 3:45 a.m. at the Santa Clara Waste Water Co., spreading about 1,200 gallons of a mysterious waste chemical mixture that contained sulfuric acid and a highly combustible organic peroxide, fire officials said.
"As the liquid began to dry out, the (fire engine) companies on scene noticed that it was very unstable and reactive," Ventura County fire Capt. Mike Lindbery said. "And as they stepped on it, or tried to move their engine, it would spontaneously ignite under the tires of the engine or their boots."
No burn injuries were reported, but two drivers on a vacuum truck, three firefighters, hospital medical staff and a few nearby residents were washed down or treated for complaints such as breathing problems, red eyes and skin rashes, said Lori Ross, a spokeswoman for the Ventura County Fire Department.
Fire Engineer Rick Macklin said 37 people were taken to hospitals, including one from the initial blast who had non-life-threatening trauma injuries.
However, hospital and other estimates put the figure at 46, although by midafternoon, only one person remained at the hospital and was in stable condition, the Ventura County Star reported.
There was no immediate way to reconcile the different figures.
Firefighters backed off and let the fires burn themselves out rather than try to put water on the chemical and potentially flush it into the nearby Santa Clara River.
Concerned that toxic smoke might be drifting from the fires, authorities ordered the evacuation of the area within a mile of the plant, but the area is mostly composed of farmland, light industrial businesses and only a few homes, Ross said.
Two schools were closed, along with the Santa Paula satellite campus of Ventura College.
As the day ended, the fires wound down, winds eased and the evacuation area was reduced to a half-mile, Macklin said. "The weather is now in our favor," he said.
By early evening, hazardous materials teams had begun entering the plant to sample the chemical mixture and were expected to remain there most of the night, Macklin said.
Santa Paula, with a population of about 30,000, is about 50 miles northwest of Los Angeles.