The suit was filed Wednesday in state Superior Court.
Hundreds of people who live or work near the site of the Nov. 30 derailment in Paulsboro have sued or plan to over exposure to vinyl chloride that was released from a ruptured tanker car.
In the latest suit, the public safety workers contend that Conrail officials were telling them that the cloud of gas was "not that toxic" even though the company knew there were dangerous levels of it.
Vinyl chloride has been linked to cancer in high amounts.
A Conrail spokesman says the company will respond in court.