If the rail car begins to cool, it will mitigate the risk of an explosion. However, that process could take days.
PERRIS, Calif. (KABC) -- Traffic is flowing once again and residents are allowed to go back home after a chemical leak in Perris forced evacuations and prompted the closure of the 215 Freeway.
Both directions of the 215 reopened late Friday after incident commanders deemed the contents of the rail car were not an imminent threat to the freeway, according to authorities.
The Harley Knox off-ramps remained shut down.
On Saturday morning, all evacuation orders were lifted.
The hazmat incident started around 7:40 p.m. Thursday after reports of a chemical leak from a rail car near Harvill and Oleander avenues, according to the Riverside County Fire Department.
Authorities said nearly 188,000 pounds of the chemical styrene leaked out of a rail car, creating a dangerous situation for nearby residents.
The chemical overheated and authorities said it could become volatile in that state. They feared that may cause some sort of explosion.
Authorities said the situation could extend for as many as three days due to the hazardous nature of the styrene chemical in the damaged rail car.
Roughly 170 residences and businesses were evacuated within a roughly half-mile radius of the leaking rail car, authorities said.
"This could resolve itself in two days, but it could get worse before it gets better,'' Cal Fire Division Chief John Crater said at a news conference Friday morning. "They've also said due to the heat building in the car, that builds pressure and it could have a release, meaning some sort of violent explosion. That's why we're taking an abundance of caution with this.''
Saturday's high in Perris is forecast to be 100.
On the flip side, if the rail car begins to cool, it will mitigate the explosion risk. However, that process could take days.
"Once we start seeing that that rail car is actually cooling, what that tells us is the chemical reaction that's happening in that car is actually now starting to solidify, which is the trend we want to see happening,'' county Fire Department Capt. Oscar Torres said.
Metrolink service on the 91/Perris Valley line has also been interrupted through the area, with the tracks closed between the Perris- Downtown and Moreno Valley/March Field stations. Service will remain disrupted until the situation is resolved.
City News Service, Inc. contributed to this report.