The railroad car is carrying styrene, a chemical used to make plastics and rubbers
The rail car is leaking styrene, a chemical used to make latex, rubber and some plastics, and is reportedly extremely hot.
The railway runs parallel to Interstate 215, a major highway through central California. Officials have shut down the highway in both directions and evacuated residents in the homes surrounding the leak.
The leak has occurred in the small city of Perris, just south of San Bernadino and around 70 miles east of Los Angles.
It was first reported on Thursday night. Officials responded to a plume of smoke, fire chief John Crater said on Friday morning.
The leak could resolve itself in a couple of days, or “get worse before it gets better,” the fire chief added.
It’s unclear what kind of chemical reaction occurred inside the car or how the leak began, officials said.
Around 170 homes have been evacuated over a half-mile radius, and a shelter has been opened up at a local middle school.
Since heat had built up inside the rail car, an explosion was possible, Chief Crater said. Because of the intense heat, the car was “too dangerous to get close to it,” he explained.
While the rail car had begun to cool down, it remained at over 300 degrees Fahrenheit (149 degrees Celsius) on Friday.
The rail car is currently being monitored with drones.
People exposed to a lot of styrene can suffer from irritated eyes and respiratory systems, with long-term exposure linked to nervous system damage, according to the US Center for Disease Control. Health impacts from low levels of styrene exposure are unknown, the CDC added.
Hazardous materials experts, firefighters and environmental health workers are reportedly working to manage the leak. The evacuation order for the surrounding area was still in place on early Friday afternoon.