Little General store propane explosion
09 October 2008
The US Chemical Safety Board (CSB) has concluded that inadequate propane technician and emergency responder training and unsafe propane tank placement were the primary causes of a fatal accident in January 2007 at the Little General convenience store in Ghent, West Virginia.
Little General store propane explosion
The propane explosion on January 30, 2007, killed two emergency responders and two propane technicians. Six others were injured. All of the victims had remained in the immediate vicinity of a propane release from a storage tank behind the store and did not evacuate the area. The store, which was levelled in the explosion, was located in rural West Virginia about 70 miles south of Charleston.
The draft report calls on West Virginia to provide annual hazardous materials training and drills for all firefighters and recommends improved training for propane service technicians throughout the country.
The accident occurred as a junior propane technician, who had not been formally trained and had been on the job only one-and-a-half months, prepared to transfer about 350 gallons of propane from an old 500-gallon tank to a new tank.
Propane was released from the old tank's liquid withdrawal valve after the technician removed a safety plug from the valve. The CSB later determined the valve had a manufacturing defect that caused it to be stuck in an open position. The CSB also determined that, probably because of a lack of training, the technician likely did not observe a telltale sign that the valve was defective: the safety plug has a small hole through which propane may be seen leaking if the valve is stuck open, before the plug is fully removed.
The CSB estimated the leak began at about 10:25 a.m. and that the building exploded just after 10:53 a.m.
“We investigated this accident because of the tragic, unnecessary loss of life,” said John Bresland, CSB chairman and CEO. “Nearly 30 minutes elapsed between the release and the explosion. If there'd been an evacuation during those 30 minutes, all of the lives would have been saved.”
The CSB investigation found that a propane tank had been installed against the back wall of the store in 1994 by propane supplier Southern Sun, in violation of OSHA regulations and the West Virginia state fire code, which require 500-gallon tanks to be placed at least ten feet away from buildings. Southern Sun was later acquired by Ferrellgas in 1996, but the tank remained where it was against the back wall.
On the day of the explosion, the tank location enabled the liquid and vapour shooting up from the valve to enter directly into the building through overhanging attic vents located above the tank. Propane then diffused down through the ceiling, and bathroom ventilation ducts also likely carried propane into the store.
CSB Lead Investigator Jeffrey Wanko said, “Our investigation team interviewed many delivery and service personnel who worked on this tank over the years. All of them were aware of the ten-foot separation requirement but none had reported the unsafe placement of this tank to their managers,” Personnel mistakenly believed the unsafe tank placement had been approved, possibly under a variance. Ferrellgas inspections and audits did not uncover the unsafe tank placement over many years.
Wanko said, “Had the tank been ten feet away from the building - as required by OSHA standards and the state fire code - it is unlikely that an explosive concentration of propane would have built up inside the store.”
CSB investigators found that the junior technician, an employee of Appalachian Heating, had been working alone and unsupervised on the propane system at the Little General, despite having no formal training. As propane continued to escape and infiltrate the store, the technician called his supervisor, who had left for another jobsite, then called 911. Despite the severity of the release, the technicians did not recommend an evacuation of the store and the surrounding area.
At about 10:53 a.m., the captain told the firefighter to 'Make sure everybody's out, okay?' But before the firefighter could act, the propane ignited from an undetermined source and the store exploded. Debris struck and fatally injured the two technicians, the fire captain, and an emergency medical technician. The workers inside the store survived with serious injuries.
CSB Investigations Supervisor Robert Hall said, “We found that emergency responders' training was not sufficient to enable them to recognise the need for immediate evacuation.” West Virginia only requires initial hazardous materials training for firefighters, generally a four-hour course when firefighters begin their careers, but refresher training is not required. The Ghent volunteer fire captain had received hazardous materials training only once, in 1998.
The CSB also found West Virginia and 35 other states have no requirements for training or qualification of propane technicians.
Bresland said, “Emergency responders often need to call on propane technicians for assistance during propane-related emergencies. There is a need for training of both firefighters and technicians so they may work together to safely deal with propane releases that threaten the lives of residents, workers, and responders.”
Training should include appropriate emergency measures including the need for immediate evacuation in the case of a significant propane release, the CSB said.
Wanko noted that propane emergencies occur frequently: “There are about 17 ½ million propane installations in the United States. Firefighters respond to propane emergencies nearly every day. Propane technicians, firefighters, and 911 operators have to be prepared for these emergencies.”
Wanko said that 911 operators typically use a set of guide cards to acquire pertinent information from callers and give appropriate instructions while dispatching responders to calls for help. However, there is no card specific to propane emergencies.
“Such a guide card would prompt operators to ask about the size and nature of propane leaks and potential dangers, and increase the likelihood of timely evacuations while firefighters determine the extent of the threat,” Wanko said.
The draft report recommends that the governor and legislature of West Virginia require training and qualification for all propane technicians. To improve training across the United States, the report recommends the National Fire Protection Association amend the national fire codes to call for specific training and testing for all personnel who handle propane.
To assure propane technicians are knowledgeable in handling emergencies, the draft report recommends that the Propane Education and Research Council, established by Congress to promote the safe use of propane, revise its training program to include emergency response guidance. Investigators said this training should emphasise the need to evacuate the scene of a release until all the hazards are known.
The draft report also recommends that Ferrellgas establish an improved inspection program and auditing system for propane installations.
The draft report calls on West Virginia to require annual hazardous materials training for all firefighters and emergency medical technicians in the state. The report also recommends that the West Virginia State Fire Commission require all fire departments to perform at least one hazardous materials response drill each year.
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