Authorities will conduct a controlled burn Wednesday of products that leaked from a railcar last week in Gloucester County.

Logan Township police said Wednesday morning that the planned flaring off would take about eight hours. The flames could be 30 feet high and visible for some distance from the site, which is close to I-295, authorities said.

The burn comes after a railroad tanker car leaked propylene, a flammable byproduct of oil refining and natural gas processing, in the Pureland industrial park on Thursday.

It took emergency crews more than five hours to contain the leak, which prompted road closures and evacuations of nearby warehouses.

The air quality was tested and there were no lingering hazards, officials said. Wednesday's controlled burn poses no threat to nearby residents, police said.