WHITEWATER TOWNSHIP, Ohio (AP) — An evacuation order remained in effect Wednesday for residents in an Ohio community as crews continued to work at the scene of a dangerous chemical leak.

Styrene, a toxic and flammable chemical that is used to make plastic and rubber, began leaking Tuesday afternoon from a railcar in Whitewater Township, a community of about 6,000 people just west of Cincinnati. The Hamilton County Emergency Management Agency advised anyone within a half-mile (about 800 meters) of the area near U.S. Route 50 and the Great Miami River to leave immediately.

Tom Ciuba, a spokesperson for Central Railroad of Indiana, which operates the tracks, said Wednesday that the railcar was no longer venting, He said crews worked overnight to put water on the car, but it hadn't been removed from the tracks and wouldn't be until officials determine it is safe to do so. He said air and water quality continue to be monitored, and that several roads near the area will remain closed indefinitely.

It isn't clear when the evacuation order might be lifted. The area has a mix of businesses, homes and large swaths of undeveloped land.

Several are schools were closed after the leak and remained shuttered Wednesday. No injuries have been reported.

Authorities have said a pressure release valve on the railcar was leaking the styrene, which can cause headaches, nausea and respiratory issues in the short term and more serious health problems including organ damage in the long term.