'Vent and burn' of toxic chemicals in East Palestine, Ohio train crash was 'not necessary': NTSB

On Tuesday, Jennifer Homendy, chair of the National Transportation Safety Board (NTSB), announced that a “rail car’s defective wheel bearing caused the derailment and subsequent hazardous material release” in East Palestine, Ohio, on February 3, 2023.

Investigators further found that the decision by the local incident commander three days later to conduct a vent and burn of the contents of the tank cars carrying vinyl chloride monomer “was based on incomplete and misleading information provided by Norfolk Southern officials and contractors.”

NTSB investigators found that the derailment occurred when a bearing on a hopper car failed and overheated, leading to the fiery derailment in the center of the small Ohio town. 

The investigation revealed that “the vent and burn was not necessary to prevent a tank car failure.” According to the Federal Railroad Administration, a vent and burn procedure should be a last resort when a tank car is about to fail. The investigation found that Norfolk Southern rejected three other removal methods and began planning for a vent and burn shortly after the derailment. Additionally, the severity of the hazardous materials release was substantially worse because of the continued use of DOT-111 tank cars to transport flammable liquids and other hazardous materials. 

Investigators found that during the derailment, three DOT-111 cars were mechanically breached, releasing flammable and combustible liquids that ignited. The fire spread and exposed other tank cars to heat, leading to a decision to conduct vent-and-burn action on five tank cars carrying vinyl chloride. The vent and burn resulted in a mushroom cloud that towered over the town and surrounding area. The DOT-111 tank car is being phased out of flammable liquids service because of its long record of inadequate mechanical and thermal crashworthiness and propensity to release lading in a derailment. This unacceptable safety record is why the NTSB is calling for an accelerated phaseout of DOT-111 tank cars in hazmat service.

According to the NTSB, overheated wheel bearings are a common cause of rail accidents, but hot bearing detectors are part of a system intended to warn crews to stop the train before the hot bearing can cause a derailment. However, the crew did not receive a hot bearing warning until the train passed over a detector in East Palestine when the overheated bearing was about to cause its axle to fail. The crew began to slow the train using dynamic braking, but it was too late. 38 rail cars derailed, including 11 rail tank cars carrying hazardous materials. 

Following the investigation, the NTSB issued new safety recommendations to the Secretary of Transportation, FRA, PHMSA, the state of Ohio, the Association of American Railroads, Columbiana County Emergency Management Agency, the Chlorine Institute, Norfolk Southern Railway, the International Association of Fire Chiefs, the International Association of Fire Fighters, the American Chemistry Council, Oxy Vinyls, LP and the National Volunteer Fire Council. The recommendations will be part of a more detailed report that will be released in the coming weeks.