CSB faults Georgia company in toxic cloud release

16 November 2004 17:42  [Source: ICIS news]

HOUSTON (CNI)--MFG Chemical failed to implement adequate controls to prevent a runaway reaction that forced the evacuation of more than 100 families and businesses last spring in Dalton, Georgia, according to preliminary findings released Tuesday by the US Chemical Safety and Hazard Investigation Board (CSB).

The CSB also cited emergency response problems, saying MFG was not equipped to handle a toxic release.

MFG said it disagreed with many of the CSB's preliminary findings. The agency planned to present the findings at a community meeting in Dalton Tuesday evening.

Some 154 people were decontaminated and evaluated at a local hospital after exposure to the cloud of toxic allyl alcohol and possibly hydrogen chloride in the 12 April 2004 accidental release, according to the CSB. Among those treated were 13 police officers and four ambulance personnel.

CSB investigators said the release came from a 2000-gal 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 released, forming a gas and vapour cloud that rapidly spread from the plant site into the surrounding community.

Investigators said 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, investigators said.

CSB investigators also said the MFG emergency plan for the 14 tonnes 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 Environmental Protection Agency (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, according to the CSB.

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.”

 MFG, based in Dalton, issued a statement that took issue with many of the preliminary findings.

"Contrary to the implication of the CSB preliminary findings, MFG had taken steps to provide sufficient cooling to the reaction," MFG said. "In fact, MFG had in place equipment providing cooling for a later step in the reaction that was expected to generate higher levels of heat. That step in the reaction was never reached, though the cooling equipment had pre-chilled the reactor entire reaction."

MFG said that before it brought the chemicals to its facility to perform the reaction, it notified local emergency resnders that the chemicals would be present at the plant and provided the dates that the compounding would occur. MFG said it provided emergency responders with the Material Safety Data Sheet (MSDS) for all chemicals to be used in the reaction. MFG said the sheet contained information regarding flammability, toxicity and other hazards associated with chemicals. The company said it also provided a 74-page material safety product guide to the Dalton Fire Department generated by the manufacturer providing the allyl alcohol.

Regarding the number of people who were decontaminated and treated for toxic gas and vapour exposure, MFG said it was unable to confirm that the all of the 154 people were actually decontaminated or treated for any exposure.

MFG said no definitative cause for the incident has been determined although "various possibilities and theories are being scientificially evaluated."

"MFG rejects the suggetion that it lacked sufficient safety equipment at its facility," the company said. "MFG had a foam suppresant on site to handle a spill of allyl alcohol until the Dalton Fire Department, which has foam suppressant capabilities, could arrive and take over that effort."

MFG acknowledged that it did not have an EPA risk management plan in place prior to receiving the shipment of allyl alcohol, but said it rejected any suggestion that the volume of the chemical present at the plant was related to the chemical release.

"MFG has no plans to repeat this reaction at its facility...and does not intend to attempt the production of the intended chemical," the company said.   

FG operates two plants in Dalton. The company manufactures speciality surfactants for use in the textile and coatings industries.

Investigators said 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.

CSB lead investigator John Vorderbrueggen said in a statement: “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.”

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. 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 CSB does not issue citations or fines but does make safety recommendations to plants, industry organisations, labour groups, and regulatory agencies such as the Occupational Safety and Health Administration and EPA.

By: Brian Ford
+1 713 525 2653

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