RailAmerica

(RRA)

said part of Cincinnati was evacuated Sunday night after a rail car began venting styrene.

The company said the car was on the property of its Indiana & Ohio Railway and contained an estimated 20,000 gallons of styrene. The

toxic chemical is used to make plastics, rubber and resin. The

government has found styrene to potentially cause depression, loss of concentration, weakness, fatigue and nausea when people are briefly exposed at levels above the so-called maximum contaminant level goal, and says lifetime exposure above those levels can cause liver and nerve tissue damage as well as cancer.

RailAmerica said local public officials temporarily evacuated residents and businesses, but on Wednesday morning residents and businesses were allowed to return. The company said its Indiana & Ohio Railway unit "will conduct a thorough investigation to determine the cause of the incident and what can be done to prevent such situations in the future."

On Wednesday, RailAmerica rose 6 cents to $11.24.