: US agency releases report on toxic Ohio train wreck #IndiaNEWS #International Washington, Feb 24 (IANS) The National Transportation Security Board (NTSB), a US federal agency, has released a preliminary

US agency releases report on toxic Ohio train wreck #IndiaNEWS #International
Washington, Feb 24 (IANS) The National Transportation Security Board (NTSB), a US federal agency, has released a preliminary report on the derailment of a train carrying hazardous chemicals in East Palestine, Ohio, earlier this month.
The report released on Thursday said the Norfolk Southern train passed three hot bearing detectors (HBD) on its trip before the derailment on the night of February 3, reports Xinhua news agency.
The function of the HBD is to detect overheated bearings and provide audible real-time warnings to train crews.
One of the HBDs transmitted a critical audible alarm message instructing the crew to slow and stop the train to inspect a hot axle, according to the report.
After hearing the warning, the train engineer increased the dynamic brake application to further slow and stop the train and the crew later observed fire and smoke and notified the dispatcher of a possible derailment.
The derailed equipment included 11 tank cars carrying hazardous materials that subsequently ignited, fueling fires that damaged an additional 12 non-derailed railcars.
First responders implemented a one-mile evacuation zone surrounding the derailment site that affected up to 2,000 residents.
There were no reported fatalities or injuries.
Responders mitigated the fire on February 5, the NTSB report stated. But five derailed specification tank cars carrying 115,580 gallons of vinyl chloride continued to concern authorities because the temperature inside one tank car was still rising.
This increase in temperature suggested that the vinyl chloride was undergoing a polymerization reaction, which could pose an explosion hazard.
Vinyl chloride is a colourless gas that burns easily. It does not occur naturally and must be produced industrially for its commercial uses.
Vinyl chloride exposure is associated with an increased risk of a rare form of liver cancer as well as primary liver cancer, brain and lung cancers, lymphoma, and leukemia.
The NTSB said on Thursday that responders scheduled a controlled venting of the five vinyl chloride tank cars to release and burn the vinyl chloride and dug ditches to contain released vinyl chloride liquid while it vaporized and burned.
The controlled venting began on February 6, which discharged toxic and potentially deadly fumes into the air.
While residents were allowed to return to their homes in East Palestine two days later, they remain concerned about the handling of the incident as well as the health impact of exposure to those chemicals.
The hazardous material tank cars have been decontaminated, the NTSB said.
The agencys investigators returned to Ohio earlier this week to examine each hazardous material tank car, document damage, and secure evidence for laboratory analysis.