FIP Investigation #2
Three Firefighters Injured While Recharging A Pressurized Water Fire Extinguisher
To:
Division of Safety Research, National Institute for Occupational Safety and Health
From:
Firefighter Injury Project (FIP), New Jersey Department of Health (NJDOH)
Subject:
Three Firefighters Injured While Recharging A Pressurized Water Fire Extinguisher, Firefighter Injury Investigation #2
Summary
On January 7, 1997, a 28 year-old firefighter was injured when he and two co-workers charged a pressurized water fire extinguisher with air from a self contained breathing apparatus (SCBA) air tank. The extinguisher exploded and the firefighter was injured when he was cut by the metal of the extinguisher. His two co-workers received minor injuries. NJDOH Firefighter Injury Project investigators concluded that, in order to prevent similar incidents, the following safety guidelines should be followed:
- A task hazard evaluation should be completed; policies and training should be implemented based on the findings of the hazard evaluation.
- Fire departments should establish a standard operating procedure for safely recharging pressurized water fire extinguishers.
Introduction
On January 9, 1997 the NJDOH was informed of this work-related firefighter injury by a supervisor with the NJ Department of Community Affairs, Division of Fire Safety (DFS) who also contacted the Fire Department officers to arrange a site visit. A site visit was conducted on February 4, 1997 with a representative of the NJDOH Public Employees Occupational Safety and Health (PEOSH) Program and the DFS. The three injured firefighters were interviewed and the site of the incident observed.
The employer of the three firefighters was a paid, municipal fire department in a New Jersey city that employed 162 persons. The department had six fire stations with six engines, three trucks, and a hazardous materials unit. The department answered approximately 5000 calls in 1996. The fire department employed a full time training officer. Firefighters, who are unionized, work rotating shifts that consist of two ten hour days, off duty for 48 hours, return for two 14 hour shifts, and then off duty for 72 hours.
The fire station to which the injured firefighters were assigned serviced a section of the city that was heavily industrialized as well as a smaller residential area. Firefighter # 1 had been on the job less than two years. Firefighter # 2 and # 3 had less than four years experience. All had been trained through a Firefighter 1 course.
Investigation
The incident occurred on the apparatus floor of the of the fire station. The apparatus floor is the section of the fire station that houses the fire trucks (apparatus). The two bay doors were closed and the fire trucks were parked inside. The crew had started their first day shift at 8 a.m. that morning and firefighter # 1 was conducting an equipment check at 12:45 p.m.. Since he was the assigned driver, part of his job was to check the truck-mounted fire extinguisher. He noted that the indicator on the pressurized water fire extinguisher read low and informed his commanding officer, an acting lieutenant, who advised checking the pressure by attempting to spray water from the extinguisher. The water only dribbled out, indicating loss of pressure in the cylinder.
The firefighter filled the extinguisher with 2 ½ gallons of water and reassembled it. The firefighter was following the procedure he had observed and performed many times before. He obtained a SCBA air tank which had been taken out of service and no longer used for breathing air. The tank had a short air hose (approximately two feet long) connected to it that was frayed and wrapped with black tape. The firefighter connected the air hose to the valve of the extinguisher; there was no regulator on the connection between the air tank and the extinguisher. The SCBA tank may have contained more than 2000 pounds of pressure. The extinguisher, which they normally charged with about 125 pounds of pressure, was placed upright on the floor. Firefighter # 2 steadied the extinguisher while firefighter # 3 stood behind firefighter # 2. Firefighter # 1 knelt on one knee in front of the cylinder so he could observe the gauge and opened the valve on the SCBA tank. The needle on the extinguisher didn't move (it was apparently defective). He decided to use more air and opened the valve again. On his third attempt, they saw that the gauge was moving. It was then that the extinguisher exploded with a deafening sound. The extinguisher exploded downward, splitting almost in two and mangling the metal. The plastic at its base shattered. No damage was done to any equipment or any part of the room.
Injuries
Firefighter # 1 was wearing leather work boots and the metal cut through the leather to lacerate his foot, severing a tendon and bone. He also had lacerations to his knee. He was removed from the fire station by an ambulance and air transported to the nearest trauma center, in another city. Surgery was performed a few hours after the incident and he was hospitalized for four days. It was anticipated that he would be able to fully resume his firefighter duties within a few months of the injury. Firefighter # 2 was treated in the local hospital emergency room. He experienced ringing in his ears and a smashed finger. He returned to light duty after three weeks and his hearing was unimpaired. Firefighter # 3 was also treated for ear trauma in the local hospital emergency room. He returned to full duty three weeks after the incident.
A critical incident stress debriefing unit provided counseling to firefighters involved in the incident.
Recommendations/Discussions
Recommendation #1:
A task hazard evaluation should be completed; policies and training should be implemented based upon the findings of the hazard evaluation.
Discussion: Although the department's firefighting activities have been reviewed and extensively taught, department officers should conduct a task hazard evaluation that focuses on non- firefighting jobs the firefighters are expected to do. The evaluation will be more effective if done with input from the firefighters. The task analysis should examine all areas and equipment for hazards the firefighters may encounter.
After identifying potential hazards, firefighters should be instructed on how to correct or avoid them. Standard operating procedures should be written and firefighters trained in appropriate work practices.
Recommendation #2:
Fire departments should establish a standard operating procedure for safely recharging pressurized water fire extinguishers.
Discussion: The fire department did not have a standard operating procedure on how to fill and charge the extinguishers. Although the firefighters involved in this incident were not formally instructed to fill and charge the pressurized water extinguishers, they were taught on-the-job by more senior firefighters and had completed the procedure several times. The method they used was one of several that had become common practice throughout the fire department. Until 1992, the extinguishers were filled and repaired at a fire department repair facility.
The manufacturer's label on the canister did not give specific directions on how to maintain or recharge the canister but did state that the extinguisher should be recharged with 2 ½ gallons of clean water and pressurized with air to 100 psi by an authorized distributor in accordance with the service manual. The service manual, obtained from a firefighting equipment supplier, gives directions for maintenance and recharging. Included are warnings to use a regulated pressurizing source (air or nitrogen) and set the regulator no more than 25 psi higher than the gauge operating pressure. Instructions in the service manual include setting the pressure regulator to no more than 125 psi.
few days after this incident, the department fire chief issued an order that no firefighter is to repair or refill a fire extinguisher. All extinguishers needing refilling or repair will be taken out of service and sent to an outside contractor.
It is unknown how most fire departments refill and recharge their pressurized water fire extinguishers, but a similar practice is apparently used in other fire departments. It is recommended that, for those departments that will service their own pressurized water extinguishers, a standard operating procedure should be researched and developed, based on manufacturers' recommendations, and formally taught to all firefighters involved in this procedure.
Attachment
- U.S. Department of Labor, Occupational Safety and Health Administration, Job Hazard Analysis 1988, (OSHA 3071)
Reference
- National Fire Protection Association # 10, Standard for Portable Fire Extinguishers, 1988.
