JURUPA VALLEY, Calif. --Cal-Fire and Riverside County firefighters responded to a hazardous-materials situation in Jurupa Valley Friday night.
At least 35 employees were initally affected by the odor from an unknown substance at Swift Transportation, located at 11888 Mission Boulevard, according to authorities.
Forty firefighters responded to the scene. Affected employees were being treated in triage areas in the parking lot. Many victims were given oxygen and rinsed off with a fire hose before being taken to a hospital.
Nineteen employees were transported to an area hospital via ground ambulance. Ten more were transported to an area hospital via a Riverside Transit Authority (RTA) bus, according to authorities.
Melody Hendrickson, a spokeswoman for the California Department of Forestry and Fire Protection in Riverside County, said Saturday that sodium benzoate was the cause of the fumes. The substance becomes an irritant when it becomes moist.
Hendrickson said none of those hospitalized were seriously injured.
The Associated Press contributed to this report.