Dalton, Georgia, November 16, 2004 - The U.S. Chemical Safety and Hazard Investigation Board (CSB) today released preliminary findings on the April 2004 toxic gas release from MFG Chemical Inc. in Dalton, which forced the evacuation of more than 100 families and businesses. The findings were to be presented at a CSB community meeting in Dalton this evening.
Some 154 people had to be decontaminated and evaluated at a local hospital after exposure to the cloud of toxic allyl alcohol and possibly hydrogen chloride. Among those treated were 13 police officers and four ambulance personnel. In addition, 122 persons had to be sheltered in a church during the evacuation of a nearby neighborhood northeast of the plant. Contaminated water runoff from the MFG facility killed fish and other aquatic life for seven miles along two creeks.
The community meeting will be held at 7 p.m. tonight at the North West Georgia Trade and Convention Center, located at 2211 Dug Gap Battle Road in Dalton. At the meeting the Board will take comments from members of the public affected by the accident, as well as testimony from a panel of local emergency response officials. This information may help the Board develop findings, root causes, and recommendations for the final investigation report on the accident.
CSB investigators have determined that the toxic release occurred from a 2,000-gallon chemical reactor during the first-ever production-scale batch of triallyl cyanurate (TAC) at MFG. The reactor over-pressurized, bursting a safety device known as a "rupture disk." When the rupture disk burst, allyl alcohol and possibly hydrogen chloride were immediately released to the atmosphere, forming a gas and vapor cloud that rapidly spread from the plant site into the surrounding community.
In preliminary findings released today, investigators said that the reaction to make TAC generates significant heat and can self-accelerate or "run away" if the heat is not removed quickly enough. Although MFG conducted some laboratory tests and test runs in a small reactor, operators did not take into account that the heat could not be removed as quickly from a large reactor. Furthermore, MFG did not implement adequate controls to prevent a runaway reaction.
CSB investigators also found the MFG emergency plan for the 31,000 pounds of allyl alcohol present at the site focused only on its flammability, not its toxicity. Toxic effects of allyl alcohol include severe eye and respiratory irritation; more serious or prolonged exposures may cause lung, liver, and kidney complications. Investigators said MFG was not equipped to handle a toxic release, and when the release did occur the company communicated only the fire hazards of allyl alcohol to local responders. MFG was also unaware of federal EPA regulations that cover allyl alcohol as a toxic substance and that require an assessment of process hazards as well as the development of comprehensive accident prevention and response plans.
CSB Chairman Carolyn Merritt said, "This is yet another serious industrial accident that endangered the public and resulted from an uncontrolled chemical reaction. It is vital that chemical operators properly assess the hazards of reactive processes and put appropriate safeguards and emergency plans into place."
A recent study by the Board identified 167 serious reactive chemical accidents in the U.S. between 1980 and 2001 that caused a total of more than a hundred fatalities. Since the study was issued in September 2002, the Board has investigated seven other serious reactive accidents, including the accident at MFG, and has tracked about two dozen other related incidents.
Investigators anticipate gathering additional information from local emergency responders at the community meeting. Investigators have thus far determined that the fire and police departments responded rapidly to the accident scene and quickly began evacuations and other protective measures. However, a variety of problems surfaced during the more than 16 hours between the beginning of the release and the final sealing of the reactor.
For example, the Dalton fire department lacked specialized equipment needed to handle a toxic release, such as protective "level A" suits, the CSB said. They also had no monitoring devices to detect airborne toxic chemicals being released from the reactor. Likewise, Dalton police lacked protective equipment and were forced to withdraw from the area during the evacuation. Ambulance crews were unaware they were entering a toxic hazard zone and some crew members were sickened from chemical exposure and became unable to evaluate and treat injured personnel or transport victims to the hospital.
CSB lead investigator John Vorderbrueggen said, "Dalton firefighters and police put their lives on the line going into the affected area, trying to contain the release and helping residents to evacuate. However, they lacked the equipment, training, and hazard information needed to effectively and safely respond to this kind of incident."
Mr. Vorderbrueggen said the next steps in the investigation will include completing chemical testing, analyzing information gathered from the community meeting, and determining the root causes of the accident. The final report, expected next year, will contain safety recommendations to the company and others to prevent recurrences.
The CSB is an independent federal agency charged with investigating industrial chemical accidents. The agency's board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in safety management systems.
The Board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA. Further information about the CSB is available from www.csb.gov. For more information, contact Sandy Gilmour (202-251-5496) or Kara Wenzel (202-577-8448) in Dalton or Daniel Horowitz (202-261-7613) at CSB headquarters in Washington, DC.