The suit, filed in Common Pleas Court in Philadelphia, names Conrail and its parent companies, Norfolk southern Corp. and CSX Corp., as defendants.
Plaintiffs include 12 Paulsboro and Greenwich Township officers who responded, along with some of their spouses and children. A Paulsboro public works employee who helped officers put up barricades is among the group.
Vinyl chloride is a flammable gas that has been linked to liver cancer, notes the suit, which says exposure affects the central nervous system.
"The purpose of this suit is to call attention to the complete failure of the emergency response and the failure to protect the first responders," said Mark R. Cuker, an attorney with the Philadelphia firm of Williams Cuker Berezofsky, one of the offices representing plaintiffs.
"Conrail put the safety of the officers last, not first," he said.
First responders, who worked 12-hour shifts, were not immediately warned about the high levels of vinyl chloride in the area. They were not given breathing masks initially, and when they got them four days later, they lacked filter cartridges, he said.
In one cited instance, Paulsboro Patrolman Rodney Richards and Sgt. Donald Grey were at a meeting at the Wells Fargo Bank in Paulsboro on Dec. 3 and saw responders rushing away from the nearby scene. The officers only learned about another release of vinyl chloride "through word of mouth," the suit says.
The environmental contractors, who were hired by Conrail, had left around 4 p.m. Dec. 3 without alerting people about the exposure, the suit said.
Mike Hotra, a Conrail spokesman, declined to comment in detail on the suit.
"Conrail will respond to this lawsuit in court and through our legal filings," he said Tuesday.
The suit also alleges that the defendants failed to provide proper environmental and biological monitoring.
The suit seeks unspecified monetary damages and medical monitoring and care. It is among at least a dozen suits filed against the three companies since the derailment. Conrail officials knew there were problems with the Paulsboro bridge mechanism and signal, the plaintiffs say.
Conrail had received 23 "trouble tickets" from crews and others about the bridge in the preceding year, including nine such reports since Oct. 27, officials of the National Transportation Safety Board said in December.
A crew report Nov. 19 indicated that the bridge had not locked properly, and on Nov. 29, a day before the accident, a crew reported that the rails were four inches away from being locked, the NTSB said.
"The bridge was an accident waiting to happen," Cuker said.
Contact Darran Simon at 856-779-3829 or at dsimon@phillynews, or follow on Twitter @darransimon.