Two CSX trains derailed yesterday in Westmoreland County, and authorities were still working in the afternoon to contain a paint additive leaking from a ruptured tanker car.

No one was injured in the 10 a.m. derailment that affected mixed-freight trains traveling in opposite directions in Reduction, CSX spokesman Garrick Francis said.

A westbound train heading from New Castle to Chicago derailed first. An eastbound train going from Willard, Ohio to Cumberland, Md. then struck one of the derailed cars, causing it to go off the rails, Mr. Francis said. The result was a 22-car pileup.

Authorities were concerned that the additive might enter a stream running parallel to the railroad tracks, Mr. Francis said.

CSX employees were working with local firefighters to contain the spill. Investigators had not pinpointed the cause for the initial derailment.

Mr. Francis said the state Department of Environmental Protection had been notified.