Refiner PBF Energy will only use safer railcars to move Bakken crude oil starting on April 1, Chairman Tom O’Malley said on Thursday, as the industry faces pressure to rely on newer cars that can better withstand crashes.

“While we are expanding our rail operations we are doing so with a keen focus on safety,” he told investors on a quarterly results call.

A spate of fiery crashes involving trains carrying crude oil has put pressure on producers, railroads and refiners to redouble safety procedures.

A Norfolk Southern Corp train carrying crude oil derailed in Pennsylvania on Thursday.