On July 2, 2015, a train derailment and fire shortly after midnight near Maryville, Tennessee caused more than 5,000 people to have to be evacuated because one of the derailed railcars carried flammable acrylonitrile – also known as vinyl cyanide, a confirmed animal carcinogen and probable human carcinogen – had caught fire and was releasing toxic black smoke including hydrogen cyanide. A mandatory evacuation was ordered for everyone within a 1.5 mile radius of the fire, which was finally extinguished almost 24 hours later.
The train had 57 railcars, of which 27 carried hazardous materials. Ten first responders and some residents were treated for irritation due to smoke inhalation, headaches, dizziness and nausea, Twenty-five people had to be hospitalized. The cause of the derailment is unclear, but the rail car carrying the acrylonitrile had a broken axel which apparently punctured the tank.
On May 4, 2013, a train transporting acrylonitrile, butadiene and triethylaluminum derailed at Wetteren, Belgium, resulting in several rail cars carrying acrylonitrile exploding with fire. More than 2,000 people were evacuated. Responders concentrated on cooling intact railcars with water. The acrylonitrile fire produced a toxic cloud containing hydrogen cyanide. One nearby resident died and two other residents experienced life threatening injuries due to inhalation. about 200 people sought treatment at surrounding hospitals.
Aristatek, Inc, a leading provider of hazardous materials planning and response solutions, has prepared a written brief detailing the consequences of vapor cloud explosions, fireballs and toxic plumes for various quantities of acrylonitrile which the company will make available at no cost to hazmat teams, fire departments/fire marshals, sheriffs, and other first responders and emergency response officials and public safety/health professionals. The document is available to those that visit the Aristatek’s website at www.aristatek.com.
Aristatek’s Acrylonitrile Brief was prepared to help with planning and response to accidents involving acrylonitrile, a flammable liquid used in the manufacture of resins and plastics.
“Acrylonitrile is probably not a substance on the minds of many emergency planners and responders,” stated Bruce King, CEO of AristaTek, “However, after the recent accident in Tennessee involving the substance, questions started coming in from our customers about this substance and they wanted more information.”
According to Aristatek, “Acrylonitrile presents several hazards when it is spilled in the environment and the brief summarizes these hazards in useful tables. The first hazards happen when spilled acrylonitrile vaporizes, contacts an ignition source, explodes and also rapidly burns in a fireball. The resulting hazards are an explosion whose blast is measured in overpressure, and thefireball which has a burn hazard for those standing too close. The other hazard is an inhalation hazard associated with an evaporating pool of spilled acrylonitrile. The tables [in the technical brief] offer safe-standoff distances for various quantities of spilled acrylonitrile for all three hazards.”
“We prepared the tables of hazards using our flagship PEAC-WMD software,” King said, saying, “We are proud to continue to provide free resources to the emergency planners and responders tasked with protecting our communities.”
Exposure symptoms are similar to cyanide poisoning. Inhalation or ingestion may cause dizziness, headache, nausea, vomiting, weakness tremor and shortness of breath. Ingestion causes abdominal pain, irritation of eyes, throat and respiratory tract. Prolonged skin contact can result in blisters and systemic toxicity due to absorption through skin. The affected area may resemble a second degree thermal burn. There’s also the possibility of liver and kidney damage. Air concentrations irritating to adults may be fatal to children.