Officials with materials maker Oxy Vinyls LP and Norfolk Southern Corp. were questioned at a two-day government hearing on the February train derailment and burnoff of plastics feedstock vinyl chloride monomer (VCM) in East Palestine, Ohio.
The hearing was held June 22-23 at East Palestine High School. At the hearing, Paul Thomas — vice president of health, environment, safety and security with Dallas-based Oxy, which owned the VCM being transported — said Oxy officials "made it clear that the VCM was not likely to spontaneously polymerize under the conditions described to us by Norfolk Southern and their contractors."
After the derailment, polymerization could have caused one or all of the VCM cars to explode. Oxy had a three-person team on-site shortly after the derailment took place. Thomas said the team told NS three times that polymerization wasn't occurring in the VCM rail cars. "We did not participate in or recommend the decision on the burnoff," he added.
The burnoff of almost 116,000 gallons of VCM contained in the five rail cars led to chemical odors and thick black smoke throughout the area. Some local residents were treated for respiratory and other medical issues related to the burnoff. The derailment and burnoff caused residents living within a mile of the site to be evacuated for several days.
NS hazardous materials director Robert Wood also spoke at the hearings. He said NS communicated with the Oxy team and other experts at the site but added that the railroad "was assessing a high-risk situation in real time."
"We observed what we believed to be multiple signs of polymerization in the tank cars containing VCM," Wood added. "Our concern grew quickly because an uncontrolled explosion of a tank car would be catastrophic.
"If polymerization occurred, rapid action would be needed to prevent an uncontrolled or potentially deadly explosion," he said.
After other options were considered "too dangerous and potentially ineffective," Wood said a controlled burnoff of the VCM "was determined to be the best and safest action." He added that the decision was made by the incident commander, East Palestine Fire Chief Keith Drabick, and "was supported by all members of unified command."
Many documents regarding the incident were supplied at the hearing, including an April 14 letter from Oxy — one of North America's largest producers of PVC resin — to National Transportation Safety Board investigator Ruben Payan. In the letter, Oxy officials said personnel responding to the scene may have misunderstood some factors that could have caused polymerization after the derailment. These factors include the significance of temperature reading and the activation of pressure-release devices.
"We are concerned some of the parties may have already concluded the content of one or more of the rail cars carrying stabilized VCM were undergoing a polymerization reaction," Oxy officials said. "Oxy Vinyls does not believe that the evidence confirms such a determination, and we caution against a premature conclusion regarding polymerization."