Jackson, Mississippi, June 12, 2007 - In a case study report released today on a fatal explosion and fire last year at a Smith County oilfield, the U.S. Chemical Safety Board (CSB) found that unsafe work practices were the cause of the accident and recommended increased Occupational Safety and Health Administration (OSHA) inspections of the region's oil and gas production facilities.
The report also called on the Mississippi Oil and Gas Board to identify, and refer to OSHA, potentially unsafe health and safety conditions observed during field inspections of well sites and drilling operations.
At around 8:30 a.m. on Monday, June 5, 2006, loud explosions and a fire were reported at the Partridge-Raleigh oilfield in Raleigh, Mississippi. Three contractors died and one contractor suffered serious injuries. The contractors, all employees of Stringer's Oilfield Services, were completing piping connections between tanks when welding sparks ignited flammable vapor venting from one of the tanks.
Partridge-Raleigh earlier contracted with Stringer's Oilfield Services to relocate three oil production tanks located on the Partridge property. Four tanks were arranged in a straight line approximately four feet apart where the workers were to perform the tank connection. The tanks ranged from 15 to 20 feet tall and 12.5 feet in diameter. The tank contents included flammable hydrocarbons, ethyl benzene, xylene, toluene, and naphthalene fumes.
On the day of the accident, two Stringer's workers and a foreman had climbed on top of the tanks and placed a ladder between two tanks to serve as a makeshift scaffold. A welder attached his safety harness to the top of one of the tanks and positioned himself on a ladder. To connect the piping to the two tanks, the welder had to weld a pipe fitting onto the side of one tank before attaching a short length of pipe to the fitting and to a nearby, open-ended pipe on an adjacent tank.
Almost immediately after the welder started welding, flammable hydrocarbon vapor venting from the open-ended pipe ignited. Welding sparks ignited flammable vapor escaping from the open-ended pipe about four feet from the contractors' welding activity.
The fire flashed back into the tank on which the two workers were holding the ladder and also quickly flashed back into the third tank. The pressure from the burning vapor inside the two tanks caused the tops to blow off. The workers were thrown by the force of the explosion, which resulted in blunt force trauma and fatal injuries. The welder suffered a broken ankle and hip, but survived since he was wearing a safety harness that prevented him from falling to the ground.
The investigation found that unsafe work practices directly contributed to the severity of this accident. The ladder placed between the tanks should not have been used as a makeshift work platform and the open pipe on the adjacent tank was not capped, or otherwise isolated with a closed valve to prevent flammable vapor from accumulating near the area where the welding was to be done.
Additionally, while not a cause of the accident, the welder inserted a lit oxy-acetylene welding torch into the tank's hatch and then into an open nozzle on the opposite side of the tank to verify that all flammable vapor was removed from the tank instead of using a flammable gas detector.
Lead Investigator Johnnie Banks said, "While recognized to be dangerous, this practice is common in oil field operations and even has a name--flashing." He added, "Neither Stringer's nor Partridge-Raleigh required hot work permits to perform welding on the tanks."
The fatality rate of the oil and gas extraction industry is over eight and a half times higher than the average for all industries in the United States. CSB Chairman Carolyn W. Merritt said, "Lives cannot be an acceptable added cost of providing fuel to American consumers."
CSB found that Stringer's lacked hot work safety procedures and did not implement available guidelines from the American Petroleum Institute (API) 2009 standard, "Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries" in preparing and conducting the welding operation on the day of the incident. In addition, Stringer's and Partridge Raleigh did not adhere to OSHA requirements addressing safe welding practices.
The CSB recommended that Stringer's Oilfield Services management develop and implement written procedures to ensure safe work practices during hot work, tank cleaning, and work from elevated locations. The CSB also recommended that Partridge Raleigh management establish written health and safety performance standards and performance metrics such as those found in the API Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operations - API RP-74.
CSB recommended the Mississippi State Oil & Gas Board (MSOGB) establish a program to identify and refer to the federal OSHA potentially unsafe health and safety conditions observed during Board field inspections of well sites and drilling operations. The program should include a written referral procedure and the training of field inspectors. MSOGB has the primary task to enforce compliance with its rules related to spill control and containment; housekeeping, such as grass control; and access to, and egress from, tanks.
The CSB also recommended that OSHA Jackson, Mississippi Area Office implement a Local Emphasis Program to inspect companies in the oil and gas production and extraction sector. Chairman Merritt said, "No worker should have to suffer injury or death to make a living. It is the responsibility of the owners to protect their employees from the hazards of the work to be performed." She added, "While it is the responsibility of the company to comply with OSHA standards, without effective enforcement, too many companies may simply ignore these life saving protective standards."
OSHA had not inspected Partridge-Raleigh or Stringer's in the three years prior to the explosion or conducted a planned inspection at any of the nearly 6000 oil fields in Mississippi in the preceding five years. Inspections were conducted resulting from employee complaints or accidents. Following the explosion, OSHA cited Stringer's for 13 serious safety violations.
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 regulations, industry standards, and 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. Visit our website, www.csb.gov.
For more information contact Jennifer Jones onsite in Jackson at (202) 577-8448 cell or Hillary Cohen (202) 261-3601 in Washington, DC.