Inadequate propane technician and emergency responder training, and unsafe propane tank placement were the primary causes of a fatal accident in January 2007 at a West Virginia convenience store, the US Chemical Safety Board said on Sept. 25.
The Jan. 30, 2007, explosion at the Little General convenience store in Ghent, about 70 miles south of Charleston, killed two emergency responders and two propane technicians, CSB investigators said in their final draft report.
Six other people were injured in the blast, they said. All had remained in the vicinity of a propane release behind the store and did not evacuate the area. The explosion leveled the store.
The final draft report, which is subject to the full CSB's approval, calls on West Virginia to provide annual hazardous materials training and drills for all firefighters. It also recommends improved training for propane service technicians throughout the United States.
It said that 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.
Defective valve
Propane was released from the old tank's liquid withdrawal valve after the technician removed a safety plug from the valve, which the CSB later determined 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.
Investigators from the federal agency estimated the leak began at about 10:25 a.m. and that the building exploded just after 10:53 a.m.
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 US Occupational Safety and Health Administration regulations and the West Virginia state fire code, which require 500-gallon tanks to be placed at least 10 feet away from buildings. Southern Sun was later acquired by Ferrellgas in 1996, but the tank remained where it was against the store's back wall.
On the day of the explosion, the tank location enabled the liquid and vapor 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, the final draft report said.
Aware of requirement
"Our investigation team interviewed many delivery and service personnel who worked on this tank over the years. All of them were aware of the 10-foot separation requirement but none had reported the unsafe placement of this tank to their managers," CSB Lead Investigator Jeffrey Wanko said. Personnel mistakenly believed the unsafe tank placement had been approved, possibly under a variance. Ferrellgas inspections and audits did not uncover the situation over many years.
"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," Wanko said.
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.
The 911 operator dispatched the Ghent Volunteer Fire Department to the report of a propane leak at the Little General. Subsequently, a volunteer fire captain, firefighter, and two emergency medical technicians arrived at the store. Four employees remained inside the store, after posting a sign saying, "Store closed due to gas leak," the CSB's draft report said.
It said that at about 10:53 a.m., the captain told the firefighter, "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.
Did not recognize need
"We found that emergency responders' training was not sufficient to enable them to recognize the need for immediate evacuation," CSB Investigations Supervisor Robert Hall said. 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 draft report said.
The CSB also found that West Virginia and 35 other states have no requirements for training or qualification of propane technicians. "'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," CSB Chairman John S. Bresland said.
Training should include appropriate emergency measures including the need for immediate evacuation in the case of a significant propane release, the CSB said.
Propane emergencies occur frequently, according to Wanko. "There are about 17.5 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," he maintained.
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, he added. "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," he said.
Draft report's recommendations
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 emphasize the need to evacuate the scene of a release until all the hazards are known.
The National Propane Gas Association established its Certified Employee Training Program (CETP) in 1988 as a formal structure for training, testing and documentation to assure that propane industry employees have the necessary knowledge and skills to work safely and effectively, according to information at NPGA's website. PERC purchased the program in 2002, and it was revised into a more flexible "modular" format in 2004 which can be used in a variety of settings, NPGA said.
The CSB's 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.
Contact Nick Snow at [email protected]