Ohio Train Derailment Probe Focuses On Failed Pressure Valves On Cars With Toxic Chemical

The investigation into the Ohio train derailment has found that aluminum parts on three tank cars may have melted and caused pressure relief devices not to function, contributing to the release of toxic chemicals last month, the National Transportation Safety Board (NTSB) said on Thursday.

The Feb. 3 derailment of a Norfolk Southern-operated train in East Palestine, Ohio caused cars carrying toxic vinyl chloride and other hazardous chemicals to spill and catch fire. Since the derailment, some of the town's 4,700 residents have reported ailments such as rashes and breathing difficulties and fear long-term health effects.

The NTSB said its preliminary examination suggested aluminum covers on protective housing for pressure relief devices on three train cars melted. This could have caused the devices not to perform as intended.

The valves seek to regulate internal pressure of the tank cars in a fire to lessen the risk of an explosion.

Calling the NTSB statement on Thursday "particularly meaningful," former NTSB investigator Russell Quimby said the aluminum covers "may have not only failed to protect, but exacerbated the situation by impeding or preventing the vent valves from properly functioning."

In East Palestine, in addition to fires started by the derailment, railroad crews intentionally drained and burned vinyl chloride from five cars three days later, on Feb. 6.

Railroad and local officials have said this was the only option to avoid a "catastrophic" explosion ignited by one car with an internal temperature at dangerous levels. Thousands of residents had to evacuate, and the operation released a massive plume of smoke.

Toxicologists say this likely sent carcinogenic pollutants including dioxins into the environment. Lawsuits against Norfolk Southern claim the disaster was avoidable and blame failed pressure relief devices.

The Pipeline and Hazardous Materials Safety Administration on Thursday urged replacing aluminum covers on the devices with carbon steel ones to avoid melting in extreme heat.

Separately, the U.S. Environmental Protection Agency said it would require Norfolk Southern to begin testing for dioxins around East Palestine.

Norfolk Southern said in a statement that it was "committed to applying lessons learned" from the derailment of the train with nearly 150 cars and that it supports "accelerated migration" of rail tank cars to a newer and safer model.

The Association of American Railroads said in a statement that the seven biggest freight railroads - including Norfolk Southern - agreed to join the Federal Railroad Administration's "close call reporting system" that protects the jobs of railroad employees who disclose safety concerns.

Last month, NTSB chair Jennifer Homendy said the derailment might have been avoided if the railway company's alarm system had warned engineers earlier that bearings were overheating.

A bipartisan group of senators led by Ohio's Sherrod Brown and J.D. Vance introduced legislation on Wednesday aimed at preventing future train disasters, and Transportation Secretary Pete Buttigieg has vowed new regulations.

Norfolk Southern CEO Alan Shaw will testify next week before a Senate committee on the derailment.

President Joe Biden said on Thursday that he would visit the site of the derailment, though he did not say when.