Ohio carries out controlled release of chemicals at train derailment site

The "controlled release" of pressurized vinyl chloride, a highly flammable and carcinogenic gas, began with a scheduled explosion, followed by continuous burning of the substance, said Sandy Mackey, a spokesperson for the Ohio Emergency Management Agency.

No injuries were reported, Mackey added.

Live video footage shot by ABC affiliate WYTV showed a towering column of thick, black smoke rising from the accident site in East Palestine, Ohio, a town close to the Pennsylvania border northwest of Pittsburgh.

The train, operated by Norfolk Southern Railroad, derailed late on Friday (February 3), setting off a massive fire that forced the evacuation of homes in the immediate vicinity.

Public safety concerns deepened after the railroad said pressure-relief devices on some of the stricken cars were found on Sunday (February 5) to have stopped working, which the company said could "result in a catastrophic failure."

Vinyl chloride is a colourless, industrially produced gas that burns easily and is used primarily in the manufacture of polyvinyl chloride (PVC) pipe and other products, according to the National Cancer Institute. It also is a byproduct of cigarette smoke.

The precise means by which crews vented the toxic gas was not explained. But the railroad said its workers had prepared drainage pits and embankments, apparently to contain residue from the release. It said state environmental officials would monitor air quality.

The company said in a short statement nearly two hours after the operation began that the "controlled breach of several rail cars has been completed successfully."

Reuters