Hotwork Accidents #1
This page was last updated on 05/06/2010
As part of the deactivation of a platform’s process drain line system, a construction employee was in the process of cutting a separator’s drain line with an electric band saw when condensate sprayed from the cut onto the employee and was ignited by the saw. The employee died days later from the resultant burns. Another employee was injured in his attempts to assist the fatally burned employee. The source of the condensate was the platform’s fuel gas scrubber whose drain line’s manual block valve was opened during the referenced construction operations. The opening of the valve and the decision of the construction employees to use the saw after previous attempts by the same employees to cut the line resulted in the spraying of condensate from the cut are considered major causes of the accident. Contributing in part to the accident were (1) a lack of procedural guidelines for the construction work to be performed, (2) misunderstandings and erroneous assumptions regarding the hot work permit, (3) a lack of adequate communication between designated operator and contractor personnel and among contractor personnel themselves, and (4) a relative unfamiliarity with the platform process equipment on the part of a contractor employee.
Therefore, from this information and information contained in the MMS report on the subject accident, the following are recommended:
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- Operators review their established procedure for coordinating proposed multiple work assignments for any facility. Operators should establish such a procedure, as described above, if one does not exist.
- Operators provide general written procedures for all construction projects, including an emphasis on safety issues. The procedures should address all aspects of the job that have been identified, through the results of a job safety analysis, as being potentially hazardous. For example, in the case of construction work to be performed on process piping, the procedures should address, but certainly not be limited to, the isolation of all relevant energy sources by, at a minimum, blinding, disconnecting, or double block and bleeding, and the purging of all involved lines prior to cutting.
- Operators review the method by which they monitor their contractors’ adherence to all agreed upon safety standards and requisite Federal regulations.
For details of the accident, see OCS Report MMS 2000-029. Copies of the report may be obtained from the MMS Public Information Office located at 1201 Elmwood Park Boulevard, New Orleans, Louisiana 70123 (1-800-200-GULF or local 504-736-2519).
Sparks ignited insulation in an already-damaged portion of a Riverside Manufacturing building at mid-afternoon Wednesday, Huron fire chief Doug Rahder said. (3/1/01)
A worker was using a cut-off saw to cut a piece of iron when sparks caught downed insulation on fire. The ceiling in the storage area on the south side of the building had collapsed earlier due to the weight of the snow. The area that was burned was less than 10 feet square, Rahder said. Workers were doing cleanup operations when the incident occurred. ©Huron Plainsman 2001
Three Men Seriously Hurt in Plant Explosion (2/28/01)
MESA, Ariz. – An explosion in an automotive airbag factory building being prepared for demolition injured three men critically, fire officials said. Fire officials said sodium azide, a powdery, volatile chemical used to deploy airbags, ignited and exploded Tuesday night at one of TRW Inc.’s Vehicle Safety Systems Inc. factories. At the time, the three TRW workers were using a blowtorch to cut pipes in a room in which sodium azide once had been stored, authorities said. The blast blew walls outward and hurled bits of debris at the men but didn’t produce a continuing fire, firefighters said. “Sodium azide is very, very explosive,” Deputy Mesa Fire Chief Mary Cammelli said, “and (it can be set off) if it’s handled in any way that is different than how it’s supposed to be handled or if there’s too much in the mix or anything. “Maybe there was some residual sodium azide that no one saw,” Cammelli added. “It just doesn’t take much of sodium azide to get an explosion.” The workers’ names and towns of residence weren’t released, but authorities said their ages ranged from 24 to 41. A 35-year-old was reported in extremely critical condition. Officials say sodium azide is known to break down quickly into nontoxic substances when exposed to air, and they did not order evacuation of surrounding homes. TRW’s two Mesa plants have been plagued with problems repeatedly over the last decade. Firefighters were called to the operations numerous times for fires and explosions mainly related to sodium azide. Neighbors filed a class-action lawsuit in April against TRW, the world’s second-largest airbag maker. The suit claims that from 1991 to 1999, fires and explosions at the plants exposed residents to sodium azide, hydrazoic acid, ammonia, chromium and nickel, harming their health and killing their pets. Overall, 16 workers were injured in 32 fires from 1993 to 1995, prompting the Mesa Fire Department to shut down one plant for a day in September 1995 to secure improved safety regulations. In April 1998, fire officials said, 1,400 pounds of sodium azide exploded in a smoke plume, but no one was hurt. In September 1994, a construction worker was killed and six employees were injured at one of the Mesa plants when ignited airbag propellant residue exploded. Cleveland, Ohio-based TRW later paid a $1.75 million fine in a plea bargain with the Arizona Attorney General’s Office to avoid a manslaughter charge. The company also agreed in January to pay nearly $25 million to settle criminal allegations that it illegally stored and dumped the toxic chemical. Investigators said TRW was shipping tons of wastewater containing sodium azide to landfills in Arizona, Utah and California. The settlement included $12 million in state and federal fines. To settle civil complaints, TRW agreed to pay a $5.67 million fine, to perform more than $5.7 million worth of projects to enhance the environment and to pay $1.5 million for cleanup of a contaminated landfill southwest of Phoenix.
Man Killed as Tank Explodes During Welding Operation; Gulfport, MS, United States; 1/17/2001- 12:00 PM
A welder working on a tank at Blacklidge Emulsion Inc. died when the tank exploded. No other injuries were reported.
The contents of the tank were not known. Larry Madison, Jr., 33, of Gulfport died as he was using a cutting torch near a tank at the company. No other details were available.
Two Workers Injured in Flash Fire at Oil Refinery; Saint John, New Brunswick, Canada; 11/1/2000- 1:00 PM
The incident occurred at the Irving Oil Refinery, the site of a billion-dollar upgrade that will significantly increase production at the plant. The facility is surrounded by homes, schools and businesses. A vacuum truck was collecting gases when some of the fumes drifted over to where a couple of welders were working. Their torches ignited the gas. The area was cordoned off and the workers were taken to the hospital. Sgt. Pat Bonner of the city police said one worker was treated and released. The other was admitted to the burn unit at the regional hospital.
Four Firefighters Injured Fighting Chemical Blaze at Plastic Hose Manufacturer; Ridgefield, NJ, United States; 10/21/2000
The fire started at the Colorite plant here when a spark from a welder’s torch ignited some chemicals at teh plant, which manufactures plastic garden hoses. Maintenance people tried unsuccessfully to extinguish the blaze, but were forced to call firefighters when they failed. Ridgefield Fire Chief John Hoffman said four firefighters were injured when water used to battle the blaze caused a chemical reaction. The four did not require hospitalization. Hoffman said there was heavy black soot and smoke in the plant when firefighters arrived. Recognizing the potential danger of a chemical fire, Hoffman called for fire companies in Cliffside Park, Leonia, Edgewater, Fort Lee and Teaneck to stand by. “It wasn’t a huge fire, but it was a dangerous fire,” he said.
Man Found Dead After Explosion Behind Drywall Company Facility; Edmonton, Alberta, Canada; 4/17/2000- 5:00 AM
An explosion behind a west Edmonton, Alberta drywall maker has claimed the life of a worker. Ed Sager, a spokesman for Occupation Health and Safety, said investigators believe the man’s cutting torch triggered the explosion. “We know the worker was cutting a piece of steel using a 45-gallon drum of asphalt primer as a work table,” Sager said. “The worker burned a hole in the top of the drum and there was an explosion. he was found buried under a pile of pallets and the ambulance crew determined he was dead at the scene,” Sager said. Jean Kirkman, spokesman for the emergency response department, said when fire officers arrived they cleared people away because the pallet fire was close to bottles of oxygen and acetylene. “Our investigators have written order to the company over safety issues but no charges have been laid yet.”
81 Miners Killed in Methane Explosion; Three Mine Officials Charged; Krasnodon, Ukraine; 3/11/2000
Three mine officials were charged with violating safety rules in connection with this incident. The state prosecutor’s office said today that former Karakova mine director Leonid Kolesnikov, chief mechanic Oleksandr Bedlovskyi and conveyor foreman Oleksandr Kryvoruchko were charged with violations of safety that led to human casualties. The three face up to 10 years in prison if convicted, prosecutors said. Earlier, a government commission ordered the mine director and several other officials dismissed from their jobs because of the explosion. According to the commission, the blast was caused by gross neglect. It said a faulty cutting torch released a stream of oxygen and caused coal dust to explode. Contrary to safety rules, worker access to the area where the cutting work took place was not restricted, investigators said. They also said experts were not present, the area was not saturated with water as required and fire extinguishers were not at hand.
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Information Added: Monday, March 13, 2000 – 12:25 PM
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Rescue crews on Sunday dragged up the last of 81 people killed in a methane explosion in an eastern Ukrainian coal mine, the former Soviet republic’s worst mine disaster in decades. A preliminary investigation suggested that safety violations led to the accident Saturday at the Barakova mine in Krasnodon, about 425 miles east of Kiev, the Interfax news agency quoted President Leonid Kuchma as saying. Kuchma criticized the irresponsibility and neglect that has caused many job-related disasters in Ukraine in recent years. “If we do not finish with this (irresponsibility), how will we dare to look in the eyes of the victims’ families,” Kuchma said during a visit to Ukraine’s western city of Lviv, according to Interfax. Ukraine has the world’s highest coal industry death rate, blamed largely on outdated and badly functioning equipment and miners’ neglect of safety rules. Its mine accidents are often caused by methane, a naturally occurring, colorless, odorless and highly explosive gas that seeps out of coal seams and can build up easily in poorly ventilated mine shafts. At least eight miners were taken alive from the shaft after Saturday’s blast and hospitalized with burns. One died of injuries Sunday, hospital officials said. Nearly 200 miners escaped the shaft safely after the explosion, which happened at a depth of 2,191 feet. The 80 other workers in the mine at the time were killed immediately, the Emergency Situations Ministry said. Thirty-three rescue units worked through the night at the site, and dragged up the last of the bodies Sunday. Relatives and colleagues milled about the mine through the night, embracing and weeping in a light snow. Ashen-faced workers lined up to read a handwritten list of those killed posted on a wall in the mine’s offices. Ukraine’s mine elevators are made of rickety wooden planks and rusty wheels, and tattered ropes that struggle to haul workers up and down several times a day. A special government commission, which included Labor Minister Ivan Sakhan, Energy Minister Serhiy Tulub and local authorities representatives, started investigation Sunday on possible causes of the accident. Prime Minister Viktor Yushchenko, who heads the commission, will arrive in the region on Monday, Interfax said.
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Information Added: Monday, March 13, 2000 – 11:49 AM
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Ashen-faced relatives stood in silence beneath a light snow, watching rescuers coated in coal dust drag up the bodies of 81 people killed in a Ukrainian mine explosion and load them onto refrigerator trucks Sunday. Survivors of the former Soviet republic’s worst mine disaster in decades described a confusing burst, a suffocating cloud of coal dust and the sickening smell of smoke before they were brought to the surface. A preliminary investigation suggested that Saturday’s accident was a methane explosion caused by a violation of safety regulations, the Interfax news agency quoted President Leonid Kuchma as saying. It occurred at the Barakova mine near the eastern town of Krasnodon. While Ukraine has the world’s highest coal industry death rate, the Barakova mine hadn’t seen major accidents before. Instead, it was known for the passion of its 3,000 workers, ever-ready to launch a strike to demand back wages and stand up for their rights in one of Ukraine’s poorest industries. On Sunday, that enthusiasm was nowhere to be found. A few grief-stricken miners wandered aimlessly among the crumbling premises of the mine, whose rusty, creaky elevators stand against the dark pyramids of coal rock. Several rescue workers in dirty orange overalls were packing their gear, the last of the 33 teams who worked since Saturday to pull the dead up from the rubble, at a depth of 664 meters (2,191 feet). Officials said 80 of the 277 miners who were underground at the time of the explosion died on the spot. Most of the others escaped safely. One died Sunday in the hospital. Seven coal workers remained hospitalized with wounds. One of them, interviewed in his hospital bed, described the moment of the blast on Russia’s NTV television. “I heard a burst, then saw cloudy coal dust, there was the smell of fire,” the survivor said through glazed eyes. His name was not given. “I called the dispatcher, and she said, ‘There’s been an explosion, you guys are the only ones left, hurry and come back up.”’ A hand-written list of the victims’ names hung on a bulletin board at the entrance to the mine’s administration building. Next to the list were two red carnations, a notice about volleyball practice, and a note advertising a country cabin for sale. “My son, my blood!” wailed one woman wrapped in a shawl, whose 21-year-old son Andriy Li-Chan-Yuk was on the list. Three young men stopped next to the list, and one started crying, touching the written names. “Five friends at once, just like that. Friends, schoolmates,” he said, turning away. Later Sunday, many of the victims’ relatives gathered in the yard of the Krasnodon hospital. Their feet sinking into the mud, they watched as medics pulled out stretchers loaded with bodies from three large refrigerator trucks. Inside the hospital, the floor was covered with a carpet of bodies. Forensic experts stepped over the corpses, most of them naked, trying to identify them. One miner was laying fully dressed, his hands resting peacefully on his chest. The accident underlined the messy state of Ukraine’s coal industry. Equipment is outdated and treacherous, and most of Ukraine’s more than 400,000 coal workers do not receive their wages on time. Much of eastern Ukraine, once proud of its coal riches, has turned into a wasteland of poverty and environmental destruction. The average monthly wage of Barakova miners is 920 hryvna (about dlrs 170), said Ukraine’s Energy Minister Serhiy Tulub. Tulub, who was at the accident site Sunday, also said safety violations were likely at fault, according by Interfax. But miners usually blame accidents on officials’ unwillingness to spend money on maintaining or upgrading equipment. Kuchma declared Monday and Tuesday days of national mourning. Many of the funerals were scheduled for Monday. Prime Minister Viktor Yushchenko was to visit the disaster site _ about 680 kilometers (420 miles) east of Ukraine’s capital, Kiev _ Monday as head of the government investigative commission. The president said the government has sent 10 million hryvna (about dlrs 1.8 million) to help the victims’ families. The number of people killed Saturday was the highest since at least 1980, when 68 people died at the Gorskaya mine in then-Soviet Ukraine. At least 274 miners died in mine accidents in Ukraine last year, down from about 360 in 1998. Ukraine’s mine accidents are often caused by methane, a naturally occurring, odorless and highly explosive gas that seeps out of coal seams and can build up easily in poorly ventilated mine shafts.
One Killed, Three Injured in Welding Incident Involving Oil Field Truck Repair; Kilgore, TX, United States; 10/17/2000- 7:00 AM
The explosion occurred at Key Energy, Inc., a New Jersey-based company. Shop foreman Ted Upmeyer, 52, was trying to weld a ball valve on the back of the oil field tanker truck when residue from a gaseous hydrocarbon ignited at Key. The blast blew a hole in the shop’s metal roof and sent pieces flying across the yard, Kilgore Assistant Chief Maxey Cerliano said. He said the explosion was felt a mile away. The three injured workers were treated and release from Laird Memorial Hospital. Key Energy employees are thoroughly trained in how to clean truck before they are returned to shops for maintenance, said Jack Loftis, the company’s general counsel. “But there must have been a flammable gas on the truck,” Loftis told the Tyler Morning Telegraph. “We are very safety conscious and if someone did not do something in the procedure, we need to find out and do our best to correct it.” He said Key Energy sent teams of safety investigators from Reno, Okla., and Kilgore to the explosion scene, where an inquiry will continue until a cause is determined. Key Energy recently purchased the Kilgore facility, which was previously supervised by Dawson Productions adn Mobley Oilfield Services and has been in operation about 20 years. The Occupational Safety and Health Administration (OSHA) investigation was in the preliminary stages, according to Kathryn Delaney, area director the OSHA’s Dallas office.
Worker Killed, Two Injured When Tanker Truck Explodes During Welding Operation; Taylor, MI, United States; 10/2/2000- 3:45 PM
Police in Taylor, which is 10 miles southwest of Detroit, responded to Quality Truck and Trailer about 3:45 p.m. after an explosion that could be heard for miles. The employees were welding on the empty semitrailer when fumes apparently ignited, police said. The names of the workers and the conditions of the two people injured were not immediately available. Company officials could not be reached for comment Monday evening (10/2/2000).
Repair Shop Damaged from Welding Incident; Grand Prairie, Alberta, Canada; 3/20/2000- 11:00 AM
A tanker truck under repair at Northern Truck Services Limited exploded when sparks from a welder ignited leftover fumes after it had been emptied of its load of flammable oil well service water, according to sources. The blast blew a hole 8 meters in diameter through the sheet metal roof, dented three overhead garage doors, and caused three bay doors to bulge outwards. Neighboring businesses felt the impact of the explosion and said at first they thought that a truck had crashed into their buildings. The worker heard a “strange” noise just before the explosion and dove to safety before the tank erupted. He is reportedly unharmed. Authorities estimate damage at $350,000 to the building and about $70,000 to the truck. This was the second welding accident in Grand Prairie in a week.
Tanks at Trucking Company Explode, Injuring Two; Rosepine, LA, United States; 3/15/2000- 3:00 PM
The two men were thought to be welding when the explosions occurred. The men were putting diesel tanks and a gasoline air compressor on a 2000 model logging truck at the time of the expolsion, according to Vernon Parish Deputy Sherrif Larry Smith. Both men were employees of Jimmy Shell’s Trucking Company. The firm conducts repairs and maintenance on logging trucks and sells truck parts. An investigation is underway to determine the exact circumstances that led to the incident.
Two Killed, Two Injured In Explosion at Paper Plant; Company Says No Welding Permit Issued; Rock Hill, SC, United States; 3/14/2000- 11:30 AM
Bowater, Inc. never gave contractors SW&B the go-ahead to weld on equipment that led to this incident last month, company officials said last Friday (4/21/00). “They should not have been welding without a (Bowater) welding permit,” said Barre Mitchell, the director of technology at the Bowater plant. The company’s comments come after the York County Coroner issued a report saying inaction by both Bowater and SW&B contributed to the explosion. (see below)
As one of five factors that contributed to the accident, Bowater failed to meet general regulations for welding because it failed to physically inspect the site before issuing an in-house permit for the welding work to be done, York County Coroner Dough McKown’s report said. That allegation is “blatantly wrong,” because Bowater never have any approval for the welding that lead to the explosion, Mitchell said. “We did not know they (SW&B employees) were going to weld there,” Mitchell said. “That’s why a welding permit was not issued.”
SW&B President Scott Searway said Friday that it would be inappropriate for him to comment on Bowater’s allegation that no permit was issued, while internal and state Occupational Safety and Health Administration investigations are ongoing. McKown said Friday he stands by his report, prepared by Bill Finch of Rock Hill-based Occupational Safety Consultants, a company that often investigates work-related accidents. “It is our understanding, based on the information we have, that Bowater issued welding authoritzation,” McKown said. “If the information is incorrect, we’ll stand corrected, but I don’t know that’ll change anything. The bottom line is the work site was unsafe.” “Finger-pointing is going to go on from this point out. Someone’s gotta be the bad guy,” McKown said. But, he said, “The reason we did that report was not to lay fault with Bowater or SW&B. It’s to determin the contributing factors in those mens’ deaths.” (Source: The Herald, Rock Hill, S.C. 4/24/2000)
Blast at Furniture Plant Kills Owner; Richwood, WV, United States; 3/14/2000
A California furniture-maker who came to West Virginia to start a new business was killed Tuesday in an explosion at his company’s Richwood plant. Mark Newman, 55, of San Bernardino, Calif., was doing welding work on a discarded 55-gallon barrel when an explosion rattled Cherry Valley Furniture Co.’s warehouse. Newman was pronounced dead at the scene, Richwood Police Chief Larry Tinney said. About 13 other workers were in the factory at the time of the explosion, but they were not injured, he said. An official from the federal Occupational Safety and Health Administration is investigating. The exact cause of the blast is unknown. Richwood Mayor Jeromy Rose said the town is devastated at the loss. “A lot of people are shook up,” Rose said Wednesday. “He came to our town to help our town out (economically), and he loses his life doing it. That’s an awful big price to pay for doing something good.” Cherry Valley produces solid hardwood living room and bedroom furniture geared toward high-end buyers.
Four Recycling Workers Killed Following Gas Explosion; Hangzhou, China, Peoples Republic of; 3/14/2000
The four were sent to Dengta Village in the suburbs to cut the steel structure over an abandoned biogas generating pit. Their arc welding-cutting device ignited the remaining gas in the pit, resulting in the explosion. Local police said the men were employees of Hangzhou Materials and Wastes Recycling Company. Hangzhou is the capital of east China’s Zhejiang Province.
Firefighters Battle Fire at Fertilizer Plant; Lake Alfred, FL, United States; 3/7/2000- 10:00 AM
Plant workers at Growers Fertilizer Corporation were welding a large metal bin when chemicals inside caught fire. Workers noticed smoke about noon. The fire began inside a 12 foot by 30 foot hopper. It contained a mixture of sludge, or sewage, and ammonium nitrate used to make the fertilizer. Lake Alfred Fire Department Lt. Jeff Allen said ammonium nitrate burns quickly and is explosive. Firefighters evacuated 15 workers and were preparing to evacuate nearby buildings when they brought the fire under control, Allen said. Mutual aid was provided by Winter Haven and Polk County fire departments. Nearly 40 firefighters battled the fire. The Environmental Protection Agency and the Polk County Hazardous Materials Team were notified, and sand was placed around a nearby storm drain to contain the chemicals. There were no injuries reported. The plant is expected to be closed for several days while workers repair damage and clean up after the fire.
Man Killed While Welding Ventline on Top of Large Wastewater Tank; Anchorage, AK, United States; 2/18/2000- 2:00 PM
The man worked at Energy Recovery Services, Inc., which cleans contaminated jet fuel so it can be reused. The explosion ripped a 20-foot-by-15-foot hole in the roof and tossed several large steel support beams into the air. The Anchorage Fire Department said Dale Stetler, 44, of Palmer was welding a ventline on top of a large wastewater tank when it blew up. Investigators said Stetler was blown through the roof of the building and killed instantly, while two men welding on the side of the tank were not hurt. A police spokesman said it was amazining the other two men were not hurt. Investigators believe the tank was contaminated with some kind of combustible or flammable fumes, which possibly caused the blast. “You can drain a tank completely and even put water in there, but there’s still fumes in the metal itself and all it takes is a slight strike to blow that thing right open,” said welder Bill Triplett. Firefighters said welding on tanks can be very dangerous. “We’ve had several fatalities in Anchorage when cutting and welding has ocurred on tanks,” said Bridget Bushue of the Fire Department.
Three Die in Explosion at Hong Kong Construction Site; Hong Kong, China, Peoples Republic of; 2/12/2000
The explosion killed three and injured four others. The workers were welding near pipes containing highly flammable (unidentified) gases. The pipes exploded and sent metal flying into the air, a spokesman for the police said. The three men, aged 43, 50, and 66 died after being hit by metal plates they were working with when the explosion occurred. The conditions of the injured men were not known. Fire officials were investigating what caused the gas leak.
Welder Seriously Injured When 55-Gallon Drum Explodes; Fargo, ND, United States; 2/9/2000- 3:00 PM
The 42-year old man was welding a pipe onto the 55-gallon drum when oil vapors ignited, causing the explosion. The drum had been used to store waste oil, Maj. Mike Fonder, a Grand Forks deputy said.
The man was reported in serious condition Thursday, with head trauma and cuts to the face and neck. The incident happened in the Opp Construction shop on U.S. Highway 81. The man had been working there for about 10 days.
Plumber Working in Hospital Injured When Welding Tank Explodes; Garrison, ND, United States; 1/19/2000
The plumber was welding pipes at the Garrison hospital when the acetylene tank he was using blew up. He was doing maintenance work in a tunnel system under the building at the time of the explosion. He suffered only minor injuries and the explosion, although felt on the first floor of the hospital, caused only limited damage. The man was flown to a burn center in Minnesota.
Two Killed in Blast at Nebraska Power Plant; Hallam, NE, United States; 12/29/1999
The explosion rocked the top of the 100-foot-tall silo used to store ash from a power plant today (12/29/1999), killing two workers who were hurled to the ground more than 80 feet below. A third employee who was working with the other two was treated in a hospital for cuts and bruises. He survived because he was not standing near the door, and was instead thrown to the floor. The cause of the incident is being investigated. The three men were welding throughout the morning, and when they stopped the explosion happened, the Lancaster County sheriff, Terry Wagner, was quoted as saying. A small fire was ignited by the explosion. It burned for about an hour. The silo is used to store flying ash captured from the plant’s burning area. It is relatively new and the crew was making some modifications in its operations room. The plant is operated by the Nebraska Public Power District. The plant was shut down to allow counselors to meet with employees. 83 people work at the plant.
Three Killed, One Injured in Fuel Cistern Explosion; Zhovtneve, Ukraine; 12/24/1999
The explosion occurred while workers at a tractor depot in central Ukraine were welding the 30-ton cistern.
The cistern was empty of fuel, but was full of diesel fumes. The welding ignited the fumes, according to the Emergency Situations Ministry
Explosion Destroys Oslo Theater; Oslo, Norway; 12/23/1999- 5:00 AM
The explosion at the ABC Theater blew a 30-foot hole in one wall, blew out most windows in the first two floors and reduced the theater’s furnishings to kindling. Debris was strewn on the street and even stuck on the walls of nearby buildings after the explosion, which occurred just after 5 a.m. meaning there was no one in the building and few nearby. The cause of the explosion was not immediately known. Fire officials said it probably was due to gas leaking from welding tanks used in remodeling the six-story building. The small theater was on the first floor. The other five were being turned into a hotel that had been due to open in April.
Gas Leak, Welding Spark Suspected in Hong Kong Tunnel Explosion; Hong Kong, China, Peoples Republic of; 12/13/1999- 2:52 PM
Investigators believe a “flash over” — a concentrated cloud of flammable gas — caused Monday’s Chai Wan tunnel explosion that injured eight construction workers. Five of the eight are still hospitalized, two in critical condition, two serious and one stable. Because the tanks were intact, investigators believe that a welder’s spark ignited gas that had leaked into the tunnel. Experts conducting the investigation found evidence that a gas leak had occurred just before the explosion. The explosion occurred in a sweage tunnel being drilled 130 meters underground in Chai Wan. A spokesman for the drainage service department (DSD) said that they had told the three main contractors to pay close attention to industrial safety. The contractors conformed to safety standards by using fireproof materials for the project, which explained why damage to equipment and the number of casualties were minimal. There were 32 workers in the tunnel at the time of the blast. A witness said the explosion occurred as a technician was igniting a torch of mixed gas to cut an iron bar.
Small Explosion at Canadian Auto Plant Injures Two; London, Ontario, Canada; 11/27/1999- 7:30 AM
Two General Motors workers were taken to hospital to after a small explosion at the automotive plant Saturday morning.(11/27/99) The pair were welding and grinding a machine when a spark ignited a gas leak, causing the blast and a small fire, said Denny Lang, director of human resources and public relations for GM Diesel Division. “Our fire department had it out before the London fire department arrived,” Lang said. The two workers were given a clean bill of health at the hospital and by the company’s medical staff. They returned to work within a few hours of the blast after 7:30 a.m. There were about 100 employees working but most weren’t affected. Only the area near the incident was evacuated, Lang said. There was no impact on production and everything was back to normal by early afternoon, he said. It was not clear from the report whether natural gas or gasoline was involved in the explosion.
Explosion at Iowa Chemical Plant, Three Workers Hospitalized, 5 Others Hurt; Clinton, IA, United States; 10/28/1999- 9:10 AM
One of the workers was welding near a tank about 8 feet long and 3 feet in circumference when a flash fire, lasting only a second or two, occurred inside the tank, according to Tom Nunheimer, spokesman for Equistar Chemicals, where the incident occurred. The tank normally contains ethylene gas, but had been purged with nitrogen to ensure that none of the flammable gas remained. The concussion from the flash fire went in all directions from the tank, Nunheimer said. Company officials said investigators were interviewing witnesses to determine the cause of the blast. The tank was not damaged.
Three maintenance workers remained hospitalized today (10/29). Lonnie Boerma was in serious condition at University Hospital in Iowa City. Dan Carlson was in fair condition, while Russell Mussman was in good condition. Injuries included burns, and one of the men was knocked off a platform. Five other workers wee treated at Mercy Medical Center for cuts, bruises and minor burns and sent home. Texas-based Equistar Chemicals, with 18 factories in the Midwest and Gulf Coast, is owned by Lyondell Chemicals, Millennium Chemicals and Occidental Petroleum. The company produces ethylene, propylene, polyethylene, polypropylene, petrochemicals, wire and cable compounds, color and additive concentrates.
Welding Incident Claims Father and Son; Redcliff, Alberta, Canada; 10/27/1999- 5:30 PM
A 48 year-old man was killed instantly from an explosion that occurred inside a workshop at an industrial strip mall while he was welding the roof of a water-tanker. His 19 year-old son died in the hospital. Authorities believe that hydro-carbon fumes emanating from a combination of distillate, gaseous substances and hydro-carbons in the tank may have ignited to cause the blast. It appeared that the tank, which was used for picking up water around oil well sites, had not been purged prior to welding.
Information Added: Monday, November 1, 1999 – 4:34 PM
The Royal Canadian Mounted Police say it appears that welding sparks caused the explosion.
Nine killed, four burned at Plastics Warehouse South of Moscow, Russia; Moscow, Russia; 9/25/1999
Faulty welding equipment is reported to have sparked the fire at Khimpolimer’s (Moscow) plastics warehouse south of the capital. No other details were available. The exact date of the incident is not known.
Explosion at Polyester Plant Kills Two, Injures Two; Grover, NC, United States; 9/14/1999- 4:30 PM
Two maintenance workers welding on an outdoor chemical tank were killed, and two others injured. The employees worked for a company called Becon, a maintenance company. A company known as Ticona also operates at the same facility as KoSa, a polyester fiber manufacturer and Cleveland County’s second largest industrial employer.
Russian Chemical Plant Fire Kills Nine, Injures 4; Mytischi, Russia; 9/10/1999
What was described as a “large” fire burned through a chemical plant just north of Moscow, claiming the lives of nine workers and injuring four others. The fire was repored at the Khimpolimer plant. It was reportedly started by faulty welding equipment, according to the Interfax news agency. No other details were made available. The condition of the injured workers was not known, except that they all suffered burns of varying degrees.
Three Welders Injured In Natural Gas Pipeline Fire; El Paso, TX, United States; 9/1/1999- 3:45 PM
Three welders were injured while working on an above ground natural gas pipeline 25 miles east of El Paso, Texas.
A release reportedly occurred from a 6 inch blow off line that comes off of a 26 inch line. The “puff” release ignited into a small fire while the workers were welding near the pipeline. The three workers were taken to a hospital.
The pipeline is regulated by the Department of Transportation
Oil Tank Explodes, Two Miners Injured; Thorburn, Nova Scotia, Canada; 8/16/1999- 1:00 PM
Two men were rushed to a hospital after the oil tank on which they were using a welding torch exploded. The Labour Department is investigating the cause of the incident. The men worked at a strip mine operating under the name Thorburn Mining Ltd., a subsidiary of Pioneer Coal.
Oil Tank Explosion kills 2, Injures 1; Livingston, TN, United States; 6/30/1999- 7:30 AM
A 25-year old Overton County man (Jack Daniels of Allon) has died from his injuries suffered in the blast. The total number of fatalities in this incident now stands at three.
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Information Added: Friday, July 9, 1999 – 12:02 PM
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During the repair of an oil storage tank, a spark from a grinder, used to prepare the tank for welding, ignited gas that had built up in the tank overnight. It had been vented of gas the day before.
Fire and Explosion in Norwegian Highway Tunnel Kill Two, Injure 15; Drammen, Norway; 6/29/1999
Officials speculate that a spark from welding activity may have started this fire in a highway tunnel under construction. The fire spread to dynamite used to blast the tunnel causing an explosion that resulted in the deaths of two fire fighters and injury to fifteen other fire fighters and construction workers. Two people were also still missing at the time of the news report.
2 Killed 2 Injured When Pipe Explodes at Coal Tar Distillation Plant; Clairton, PA, United States; 12/4/1998
Information Added: Thursday, July 29, 1999 – 11:53 AM
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Two workers were killed and two injured after an explosion at Koppers Industries in Clairton, PA. The explosion occurred during welding work on a pipe connected to a coal tar distallation tank. See http://www.chemsafety.gov for additional information.
1 Killed, 2 Injured in ARCO Oil Refinery Explosion; Carson, CA, United States; 8/19/1998
A contract worker was killed and two employees were injured after a small explosion occurred during routine maintenance welding on a tank in a Cogeneration facility located on the grounds of ARCO’s Los Angeles area refinery. The welder worked for Total Western, a California firm. The two injuries were reported to be minor.
3 Killed in Explosion at Florida Trucking Co.; Brooker, FL, United States; 8/18/1998
Three people were killed in a explosion at a Crawford Trucking in Brooker, Fla. According to the Bradford County Sheriff’s department vapors ignited during a welding procedure. The CSB closed the review for this incident without issuing any findings. See http://www.chemsafety.gov for additional information.
FIRE PREVENTION DURING WELDING AND CUTTING OPERATIONS
On May 23, 1993, Reuter reported that an explosion and fire at the Zaporizha nuclear station in the Ukraine killed one worker and seriously injured another. The explosion and fire occurred when sparks from a welder’s torch ignited hydrogen from a cooling line. According to the station director, the two workers had misidentified a line for repair and dismantled part of a pipe containing hydrogen. Fires at Department of Energy facilities are not uncommon. In June 1991, the Office of Environment, Safety & Health issued Bulletin 91-3 (DOE/EH-0196), Fire Prevention Measures for Cutting/Welding Activities, in which it was reported that more than 100 fires occurred at Department facilities the previous year. Many of these fires started as a result of cutting or welding activities. According to Bulletin 91-3, most of these fires resulted from failure to follow precautionary practices such as isolation or protection of combustibles in the surrounding work area, use of fire watches, adequate authorization and supervision, and failure to meet the Occupational Safety and Health Administration fire protection requirements given in the 29 CFR 1910. Management commitment to the improved risk objectives of DOE 5480.7, Fire Protection, can lead to improvements in these areas, according to the Bulletin. More recently, several fires attributed to welding and cutting activities occurred at DOE nuclear facilities. Workers were injured during some of the fires and, in one case, a fire resulted in a site-wide ban on all welding and burning activities. Fire prevention should be an important consideration in all welding, cutting, and grinding work. Open flames, electric arcs, hot metal, sparks, and spatter are ready sources of ignition. Many fires are started by sparks that pass through small openings such as cracks or holes. When possible, welding should be performed in specifically designated areas or enclosures made of noncombustible materials and should be kept free of combustibles. When combustibles cannot be removed, they should be covered with tight-fitting, flame-resistant materials. A fire watch should be maintained where the combustibles are located. The risk of fire is increased by combustibles in the work area. Welding or cutting too close to combustibles that have not been properly shielded also causes fires. The most commonly ignited materials include floors, roofs, insulation, trash, paper, chemicals, paint, and other flammable liquids and gases. When welding outdoors, care should be taken to avoid igniting dry grass, brush, and trash. Hot work permits are useful when welding or cutting is planned in areas not normally reserved for such operations. The purpose of a hot work permit is to alert area personnel of a fire risk because of planned operations in these areas. Permits should be limited to short periods of time and one welding operation. Burns of the eye or body are serious hazards of welding. To prevent injuries to the eye, face, and body, protection for the welder and others in the work area should be required. The protective equipment worn should be appropriate to the specific welding activity. Several publications provide additional guidance on reducing fire hazards associated with welding and cutting operations. Bulletin 91-3 provides detailed recommendations on isolation or protection of combustibles in the surrounding area, use of a fire watch, elements of adequate authorization and supervision, and management commitment to loss prevention. The following are publications that contain many general and specific recommendations that should be consulted by appropriate facility personnel. Industrial Fire Hazards Handbook, 3rd ed., National Fire Protection Association, Quincy , Mass., 1990. Cutting and Welding Processes, Standard 51B, National Fire Protection Association, Quincy, Mass., 1992. Brazing Safely, American Welding Society, Miami, Fla., 1992. Arc Welding Safely, American Welding Society, Miami, Fla., 1988. Oxyfuel Gas Welding, Cutting, and Heating Safely, American Welding Society, Miami, Fla., 1992. Safe Practices, American Welding Society, Miami, Fla., 1992. Safety in Welding and Cutting, ANSI/ASC Z49.1-1988, American Welding Society, Miami, Fla., April 5, 1988.
SPARK FROM METAL CUTTING OPERATION CAUSES FILTER FIRE
On July 7, 1999, at the Allied Technology Group (ATG) Catalytics facility at Oak Ridge, contract welders cutting 1-in.-thick carbon-steel shielding caused a fire in a local-area process ventilation roughing filter constructed of pleated paper. They were cutting and shaping the shielding with an oxyacetylene torch 10 to 12 ft above floor level and approximately 3 ft from a ventilation duct when they saw flames in the filter. Facility personnel secured all ventilation fans to prevent the fire from spreading and all unnecessary personnel evacuated the building. An ATG shielding-installation supervisor attempted to extinguish the fire by injecting carbon dioxide into the ventilation duct, but this was unsuccessful. The supervisor eventually smothered the fire by removing a metal inspection plate upstream of the filter and injecting a dry chemical fire-extinguishing agent into the duct. There was no damage to the facility. The workers had unknowingly violated facility procedures that prohibited cutting, grinding, or welding within 35 ft of combustible material. This event is significant because many DOE facilities have changed over to deactivation and decommissioning activities, which increases the volume of cutting and welding operations and the hazards associated with them. (NRC Event Report Number 35914)
This facility accepts highly radioactive spent resin from commercial nuclear power plants and reduces the volume of the resin by a heated, pressurized, catalytic conversion process that creates a solid matrix of material for disposal. The facility’s radiation safety officer stated that the fire started when sparks from the cutting operation were sucked into the process filter through small holes in a ductwork seam that were not seen by the workers. Although the filter was slightly contaminated, local-area air monitors and stack samplers indicated that no radioactive release occurred, and personnel surveys indicated that no one was contaminated during the fire. The safety officer also said that facility managers prohibited any welding and cutting activity until all hot-work procedures were revised to clarify their safety requirements and the contract workers were retrained on the procedures. Additionally, facility supervisors will tour and inspect work sites prior to approving any hot-work permits and periodically when any cutting or welding operations are in progress.
A similar event also occurred recently at a commercial nuclear power plant. On July 13, 1999, welders were removing and cutting apart unused tanks in the waste evaporator feed tank room. While they were cutting a hole in a concentrator tank to characterize what remained inside the tank, their torch ignited a stainless steel mesh filter that was mounted inside the tank. The filter, which contained resin fines, ignited and smoldered. Fire brigade members extinguished the fire with a water extinguisher. (NRC Event Number 35916)
NFS has reported cutting and welding events in several Weekly Summaries. Following are some examples.
· Weekly Summary 97-45 reported that personnel at a commercial nuclear hot-cell facility reported a small fire in a flexible exhaust duct. Facility personnel believed the fire started when a piece of hot slag fell on the duct during the cutting of some steel plates being removed from a decommissioned hot cell. A fire watch extinguished the fire and was later hospitalized overnight for smoke inhalation. There was no release of radioactivity to the environment and no damage to the facility. (NRC Event Number 33204)
· Weekly Summary 97-40 reported that a safety engineer at the Savannah River Site observed several safety violations by subcontract welders during two welding operations and stopped them. The violations included fire watch violations, failure to use proper protective equipment, and combustible materials in the immediate area. Corrective actions required the subcontract personnel to review (1) requirements for preparing a work site prior to welding, (2) requirements for fire extinguishers at the work site while welding, and (3) fire watch roles and responsibilities. (ORPS Report SR–WSRC-RMAT-1997-0009)
· Weekly Summary 97-11 reported that a welder at the Oak Ridge K-25 Site was fatally burned during a cutting activity when two layers of his anti-contamination clothing and coveralls caught fire, engulfing him in flames. All of the clothing was cotton. A DOE Type A accident investigation determined that sparks or molten metal (slag) from the cutting operation ignited his clothing. (Type A Accident Investigation Board Report on the February 13, 1997, Welding/Cutting Fatality at the K-33 Building, K-25 Site Oak Ridge, Tennessee, and ORPS Report ORO–LMES-K25GENLAN-1997-0001)
These events illustrate the potential dangers associated with welding, cutting, and grinding activities. These activities pose safety and health hazards to workers under any circumstances, but they pose unique hazards to facility personnel performing decontamination and decommissioning activities. Fire prevention is an important consideration for these operations. Open flames, electric arcs, hot slag, sparks, and metal spatter are ready sources of ignition. Sparks from cutting, particularly oxyfuel gas cutting, are generally more hazardous than those from welding because the sparks are more numerous and travel greater distances because they are propelled by the oxygen or air stream used in the cutting process. Isolation or protection of combustibles is essential, for they may be exposed to sparks that fall through holes, cracks, or other openings. If those sparks retain heat for a sufficient time, they might ignite combustibles.
Managers at DOE facilities undergoing deactivation need to ensure that vendors and subcontractors understand local work control practices and the importance of following safety requirements. Several publications provide guidance on welding and cutting safety and on reducing fire hazards. The following publications contain many general and specific recommendations and should be consulted by supervisors of welding and cutting operations.
· DOE/EM-0142P, Decommissioning Handbook, March 1994, DOE Office of Environmental Restoration, provides requirements for worker protection during decontamination and decommissioning activities. It states that worker protection is an important element of any project. The handbook divides worker protection issues into three categories: (1) protection from radiation, (2) protection from toxic and hazardous materials, and (3) protection from traditional industrial safety hazards. It further states that DOE decommissioning activities may produce a combination of hazards not commonly encountered elsewhere (such as industrial safety hazards and radiological hazards) and lists OSHA regulations that apply to decommissioning, as well as key elements of a health and safety program. Section 12 of the handbook states that extra precautions are required for worker safety because hazards in the facility may be unknown and many activities are infrequently performed.
· DOE/EH-0196, Bulletin 97-3, “Fire Prevention Measures for Cutting, Welding, and Related Activities,” describes the fire protection measures necessary for those activities. Guidelines outlined in the bulletin include provisions for (1) management commitments, (2) job safety analysis, (3) permits, (4) isolation/protection of combustibles, (5) personnel protective equipment, (6) dedicated fire watches, (7) manual fire-fighting equipment, (8) emergency services, (9) site-specific hot work policies and procedures, and (10) information sharing.
· 29 CFR 1910.252, General Requirements, states that “cutting or welding shall be permitted only in areas that are or have been made fire safe.” Section (a)(2)(vii) requires relocating combustible materials at least 35 ft from the work site. Where relocation is impracticable, combustibles shall be protected with flameproofed covers or otherwise shielded with metal or asbestos guards or curtains. Subpart I, Appendix B, “Non-mandatory Compliance Guidelines for Hazard Assessment and Personal Protective Equipment Selection,” states that walk-downs of work areas should be performed to identify hazards before work begins.
· The National Fire Protection Association (NFPA) publications Industrial Fire Hazards and Standard for Fire Prevention During Welding, Cutting, and Other Hotwork provide guidance for the removal and protection of combustibles during welding and cutting activities.
· American National Standards Institute Standard Z49.1, Safety in Welding, Cutting and Allied Processes, covers all aspects of safety and health in the welding environment, emphasizing oxygen gas and arc welding processes. It contains information on protecting personnel and the general area, ventilation, fire prevention and protection, and confined spaces. Paragraph 6.2.2 requires a fire watch when combustible materials are closer than 35 ft to the point of operation. Paragraph 7.2.3 requires ducts used for local exhaust ventilation to be constructed of non-combustible materials and inspected to ensure proper function and to ensure that the internal surfaces are free of combustible residuals.
The following two welding and cutting safety publications, as well as many others, can be ordered from the American Welding Society, 550 N.W. LeJeune Road, Miami, Florida 33126, by calling (800) 443-9353, or at http://www.aws.org: Fire Safety in Welding and Cutting outlines precautionary measures and safe practices to help avoid the hazards of fire and explosion; Safe Practices covers the basic elements of safety applicable to all welding, cutting, and related processes.
DOE/EH-0197, Safety Bulletin 97-3, can be obtained at http://tis.eh.doe.gov:80/docs/ bull/links.html. OSHA regulations can be found at http://www.osha-slc.gov/OshStd_toc/OSHA_Std_toc.html. Industrial Fire Hazards and Standard for Fire Prevention During Welding, Cutting, and Other Hotwork, Standard 51B, can be obtained from the National Fire Protection Association, 1 Batterymarch Park, P.O. Box 9101, Quincy, Massachusetts 02269-9101. NFPA codes and standards can also be ordered at http://www.nfpa.org or by calling the NFPA at (800) 344-3555.
Louisiana Worker Injured in Explosion, Fire at Oil Collection Facility; Lake Rosemound, LA, United States; 10/18/1999- 8:00 AM
A worker salvaging pipe from an abandoned gas and oil collection facility in rural West Feliciana Parish was injured after he was engulfed in a fireball that erupted after an initial explosion blew the top off a 1,000-barrell crude oil storage tank. The man, Herbert Isidore, was in stable condition Monday (10/18) afternoon at the Baton Rouge General Medical Center’s Burn Unit. Sgt. Chirs Viator of the State Police Hazaradous Materials- Explosives Unit, said the crew had worked on the site for about an hour before a torch was used to cut a pipe connected to the tank that exploded. Detective Randy Holden said Isidore’s co-workers reported that the victim ran from the scene with his clothing on fire and they wrestled him to the ground and extinguished the flames. Viator and Fire Chief Tommy Boyett said the fire spred to two more tanks, including a large fiberglass unit that the heat reduced to a huge lump.
The material left in the tanks burned for about 45 minutes before firefighters moved in with chemical foam and water to cool the debris and extinguish the remaining flames. Firefighters chose not to attack the blaze because there was nothing at the abandoned site to save. The last well in production at the location was shut down about seven or eight months ago.
Torch Ignites Leaking Propane, Arizona Businesses Evacuated; Tuscon, AZ, United States; 10/4/1999
A workman’s torch ignited propane leaking from a metal cylinder causing an explosion at a storage yard. One of the tanks was ripped apart and few “like a torpedo”. It hit a building 40 feet away at a height of 15 feet, according to fire department spokesman Brian Delfs.
Woman Dies After Flash Fire; Mauldin, SC, United States; 9/2/1999
The three workers (women) were using acetone to clean a 55-gallon drum when chemical vapors apparently were ignited by the spark of a welder’s torch, fire officials said. The flames were extinguished by other employees before firefighters arrived. The incident occurred at Russell-Stanley Container Management Services plant. The other women suffered burns over 20 to 30 percent of their bodies, according to authorities. The 22-year old female victim, Catalina Munoz, succumbed after being burned on more than 80 percent of her body. The company at which she worked cleans industrial containers.
Underground Tank Explodes, One Killed, Two Injured; Wind Gap, PA, United States; 8/2/1999- 2:50 PM
A Garfield, Penn. man was killed and two workers injured when an explosion tore through an storage tank at a tire recycling facility (Tire Energy Corp.). The men were apparently inside the tank performing maintenance. One of the injured men suffered burns over 85 percent of his body. According to the Bergen Record, the men have been using a torch in the tank, which was believed to be used to store fuel derived from the recycling of tires.
Cutting Torch Sets Off Warehouse Fire; Fort Lauderdale, FL, United States; 7/6/1999- 1:00 PM
Two men trying to take apart a spray paint machine, accidentally set it on fire when they turned on an oxy-acetylene cutting torch. One of the men suffered second-degree burns. The fire inflicted about $20,000 in property damage.
Bin Welding Causes Fire. Plant workers at Growers Fertilizer Corporation were welding a large metal bin when chemicals inside caught fire. The fire began inside a 12 foot by 30 foot hopper. It contained a mixture of sludge, or sewage, and ammonium nitrate used to make the fertilizer. Ammonium nitrate burns quickly and is explosive. Firefighters evacuated 15 workers and nearby buildings. Nearly 40 firefighters battled the fire.
Tanks at Trucking Company Explode, Injuring Two. The two men were thought to be welding when the explosions occurred. The men were putting diesel tanks and a gasoline air compressor on a 2000 model logging truck at the time of the explosion.
HOT WORK ACTIVITIES RESULT IN CLOTHING FIRES
This week, Operating Experience and Feedback engineers reviewed two events where craft workers’ clothing caught fire. Both individuals were wearing flame-resistant clothing and anti-contamination clothing. One fire occurred at Hanford; the other, at a commercial nuclear power plant. Investigators determined that the Hanford fire was caused by a piece of hot slag caught in the folds of the worker’s anti-contamination clothing. The other fire was caused by a damaged hose from an acetylene-oxygen torch. Neither employee was burned. Clothing fires can be fatal, as demonstrated by the recent event at Oak Ridge, where a welder was fatally burned when his clothing caught fire. (ORPS Report RL–BHI-REMACT-1997-0005)
On May 7, 1997, two laborers at Hanford were cutting contaminated retention basin steel into 4-foot by 15-foot plates. Each laborer wore a single pair of anti-contamination coveralls, flame-resistant boot covers, leather leg coverings, and jacket. A radiological control technician in the area surveyed the plates before they were cut. When one of the laborers noticed a smell inconsistent with his cutting operation, he stopped cutting, looked around, and noticed the leg of his coveralls was on fire. The laborer put out the flame by patting it with his gloved hand.
The fire occurred at ankle level on the laborer’s anti-contamination coveralls and burned a hole approximately 8 inches in diameter. The flame-resistant boot covers he wore under the anti-contamination coveralls were also burned. There was also minor burn damage to his jeans under the protective clothing. Managers at the Hanford Remedial Action Project have suspended all hot work until they can identify safer hot work practices.
On March 24, at a commercial nuclear power plant, pipefitters were pre-heating weld lugs with an oxygen-acetylene torch inside the reactor containment building. The pipefitters worked in the area for approximately 4 hours before the fire occurred. A pipefitter torch operator finished pre-heating a plate, shut off the acetylene torch, and laid it on the concrete platform behind him. When a pipefitter welder struck an arc with his weld rod, a flash occurred and his flame-resistant welding jacket caught fire. He immediately moved the weld rod away from the plate, stopping the arc. He descended a 5-foot platform, and a firewatch immediately removed his welding hood and jacket. This action extinguished the fire. The welder was not burned, but he did receive a mild contusion on his right knee when he brushed a steel structure while descending the platform.
Investigators determined that the March 24 fire was caused by a damaged acetylene hose. The inner neoprene elastomer on the hose was degraded to the extent that gas leaked through small cracks. Investigators also determined the event was minimized by the following.
- Workers performed the hot work in accordance with the approved hot work permit. Properly trained firewatch personnel were stationed at the hot work activity and responded appropriately.
- The pipefitter welder was wearing 100 percent cotton protective clothing and an approved fire-retardant welding jacket.
- The acetylene gas pressure was regulated to less than 15 psi for safety reasons.
Managers suspended all hot work in the containment building. Inspectors removed all acetylene-oxygen hoses from the containment to conduct visual inspections and snoop-testing. They removed four hoses from service based upon their visual examination.
These events illustrate the potential hazards when clothing, including flame-resistant clothing, comes in contact with flames or hot objects. DOE O 440.1, Worker Protection Management for DOE Federal and Contractor Workers, requires DOE site organizations to implement a written worker protection program that provides a place of employment free from recognized hazards that are causing or are likely to cause death or serious physical harm. The Order also requires facilities to implement a hazard prevention and abatement process to ensure identified hazards are managed through final abatement and control. When a serious hazard is identified, management must assess the process and take appropriate steps to prevent, abate, or mitigate the hazard.
The power plant event also demonstrates the importance of having hoses in good condition, especially if they are attached to cylinders containing flammable gases. OSHA Regulation 29 CFR 1917.152 Welding, cutting and heating (hot work), section (d)(2)(v) states that hoses shall be inspected before use. Hoses subjected to flashback or showing evidence of severe wear or damage shall be tested to twice-the-normal working pressure but not less than 200 psi. The Regulation also states that defective hoses shall not be used. U.S. National Research Council publication ISBN 0-309-05229-7, Prudent Practices in the Laboratory: Handling and Disposal of Chemicals, 1995, recommends that all pressure equipment and assembled apparatus be tested and inspected periodically. The frequency of the inspection should be dependent on the frequency of use, nature of use, and the corrosive properties of the stored material. Testing assemblies with soap solution and air or nitrogen pressure to the maximum working pressure can usually detect leaks at critical points. Managers at DOE facilities should review their cylinder and hose inspection program to ensure that damaged or degraded hoses are identified and removed from service before they can cause a personnel hazard.
SMOLDERING WOOD FOUND IN REACTOR CAVITY AFTER TORCH CUTTING OPERATIONS On December 7, 1994, facility personnel at Argonne National Laboratory – East reported that on November 23, 1994, a Health Physics Technician (HPT) discovered smoke in the area of the Experimental Boiling Water Reactor (EBWR) containment where torch cutting operations had been conducted on the previous day. Managers notified fire protection personnel who sprayed the smoldering timber and then removed it in a 55-gallon drum. The EBWR is being decontaminated and decommissioned. No personnel were injured and there were no releases of radioactivity as a result of this event. (ORPS Report CH-AA-ANLE-ANLEER-1994-0017) On November 22, 1994, contractor personnel were cutting instrumentation piping in the reactor cavity using a plasma arc torch and oxy-acetylene torches. There were some sections of redwood beam supports exposed in the vicinity of the instrumentation piping. The burn permit posted at the job site required that combustible material be removed or be protected with cover material if it could not be removed. Cover materials were available on the project but the workers did not use them. The torch operator had a fire extinguisher in the man-basket and there was a fire watch posted as required by the burn permit and procedure. The operator used the fire extinguisher on several occasions to put out smoldering wood splinters. After the cutting operations, workers washed down all of the exposed wood and the fire watch remained posted for an hour. When the fire watch was completed, workers washed down the wood again and inspected the area several times – the last time, almost two hours after the cutting operation. None of the inspections revealed any flame or any signs of smoldering wood. Managers conducted a post-incident briefing with all contractor personnel on November 28, and instituted a requirement that the burn permit be reviewed during the pre-job briefing for all future work involving flame and spark producing activities. Also the contractor’s health and safety manager will inspect the work area preparations before work begins. On November 29, laboratory personnel initiated an investigation of the event to determine if work control problems exist at the EBWR Decontamination and Decommissioning (D&D) site. This event illustrates the importance of fully complying with administrative controls intended to prevent fires, especially when performing potentially hazardous operations. If the workers had either removed or properly covered the exposed wood as required by the burn permit, this event would very likely not have occurred. There was no damage to equipment because the cutting operation was part of D&D project activities and there were no other operations in the area. A similar event in an operating facility could have had significant consequences for both personnel safety and equipment operability. DOE facility personnel with responsibilities for welding or cutting operations should consider performing pre-job briefings on permit requirements and conducting work area inspections to ensure that their workers identify all potentially combustible materials in the work area and fully comply with the permits governing their activities.
SPARK FROM CUTTING TORCH CAUSES GRASS FIRE
On June 4, 1999, at Sandia National Laboratory-Albuquerque, construction contractors were using a cutting torch to remove a large I-beam from the exterior of a building when a spark, blown by high winds, caused a grass fire. The fire burned approximately 1,200 square feet of weeds and brush on top of a bunker. The contractor attempted to extinguish the fire using a fire extinguisher. Other contractors in the area responded with a water tanker to help control the fire until the fire department arrived. The fire damaged a cable on the bunker, and the inside of the building may have suffered smoke damage. The contractor was cutting without a hot-work permit and without a fire watch in conditions that were dry and hot, with 25-30 mph winds gusting to 40 mph. (ORPS Report ALO-KO-SNL-NMFAC-1999-0009)
While responding to the fire, a contractor employee fell off the water tanker truck and a Sandia employee was struck in the chest when a pressurized hose disconnected from the tanker. Both employees were treated by medical personnel and released for work. Investigators have not yet assessed the actual damages.
Investigators determined that there had been no discussion of the weather or its potential to start a fire. Nevertheless, the area where the contractors were working was posted “Extreme Fire Danger.” Investigators determined that not only did the contractor not have a permit and fire watch, but the fire extinguisher used was not rated or sized for the activity being performed and the area was not wetted or cleared of debris before cutting. Currently, Sandia’s hot-work permit process does not address wind or environmental restrictions. Facility managers will evaluate this process to determine if environmental or weather conditions need to be integrated into the hot-work permit process.
NFS has reported numerous other events involving fires started by sparks from cutting, grinding, or welding in previous Weekly Summaries. In many of these events, fire resulted when workers did not adequately review the work area for combustible materials or identify all possible paths for sparks or hot metals.
· Weekly Summary 98-49 reported that an explosion ejected weld material from a Cadweld crucible mold ignited a grass fire at the base of an explosives magazine at the Pantex Plant. Wind spread the fire to a second location on the slope of the magazine. (ORPS Report ALO-AO-MHSM-PANTEX-1998-0068)
· In a 1994 event at Los Alamos National Laboratory, a spark from a pipe-cutting operation passed through the open-ended pipe being cut to the outside of the building and fell to the ground, starting a grass fire. The grass fire caused an 8-foot-by-10-foot area of tar paper on the exterior wall of the building to burn. (ORPS Report ALO-LA-LANL-DPWEST-1994-0004)
In June 1991, the Office of Environment, Safety, and Health issued Bulletin 91-3 (DOE/EH-0196), Fire Prevention Measures for Cutting/Welding Activities. According to the bulletin, more than 100 fires occurred at DOE facilities in the previous year, most of which resulted from failure to follow precautionary practices such as isolation of combustibles in the surrounding work area, use of fire watches, adequate authorization and supervision, compliance with Occupational Safety and Health Administration (OSHA) fire protection requirements, and management commitment to fire prevention. OSHA regulation 29 CFR 1917.152, “Welding, Cutting and Heating (Hot Work),” provides the following guidance.
· To the extent possible, hot work shall be performed in designated locations that are free of hazards.
· When hot work must be performed in a location that is not free of hazards, all necessary precautions shall be taken to confine the heat, sparks, and slag so that they cannot contact flammable or combustible material.
· Fire-extinguishing equipment suitable for the location shall be immediately available and shall be maintained in readiness for use at all times.
· When the hot work operation is such that normal fire prevention precautions are not sufficient, additional personnel shall be assigned to guard against fire during hot work and for a long enough time after completion of the work to ensure that no fire hazard remains. The employer shall instruct all employees involved in hot work operations about potential fire hazards and the use of firefighting equipment.
This event illustrates the importance of performing cutting or welding operations under an approved hot-work permit that addresses precautions such as fire watches, extinguishing equipment, and barriers. Personnel responsible for preparing and issuing permits for cutting, welding, or burning should also consider weather and environmental factors such as high winds and extremely dry conditions.
Other information regarding cutting and welding safety can be found in the following documents.
· Industrial Fire Hazards Handbook, 3rd ed., National Fire Protection Association, Quincy, Massachusetts, 1990.
· Standard 51B, Cutting and Welding Processes, National Fire Protection Association, Quincy, Massachusetts, 1992.
· Brazing Safely, American Welding Society, Miami, Florida, 1992.
· Arc Welding Safely, American Welding Society, Miami, Florida, 1988.
· Oxyfuel Gas Welding, Cutting, and Heating Safely, American Welding Society, Miami, Florida, 1992.
· Safe Practices, American Welding Society, Miami, Florida, 1992.
· ANSI/ASC Z49.1-1988, Safety in Welding and Cutting, American Welding Society, Miami, Florida, April 5, 1988.
WORKER BURNED DURING WELDING OPERATION
On April 29, 1999, at the Los Alamos National Laboratory, a mechanical technician sustained second-degree burns to his left forearm and hand while welding a container in a welding shop. The technician’s welder ignited vapors from the ethanol that was used to clean the inside of the container. The ignited vapors flashed, contacting his forearm and charring and burning holes in a cotton glove that he was wearing. A coworker immediately transported him to the Los Alamos Medical Center emergency room, where he was treated and referred to a burn and trauma center in Albuquerque for evaluation and treatment of the injury. Medical personnel at the burn center evaluated the burns as second degree and released the technician the same evening. This event is significant because flammable vapors came in contact with an ignition source and resulted in an injury. (ORPS Report ALO-LA-LANL-TSF-1999-0001)
The mechanical technician was re-welding joints in a 15-gal stainless steel drum that had been modified to serve as a container for molecular sieve material. The joints had failed an earlier helium leak detection test. The technician was experienced in the operations associated with modifying drums of this type. At the time of the accident, he was working in the welding shop and he wore an approved welder’s hood and smock, as well as cotton gloves to give the dexterity and grip necessary for fine welding.
Investigators determined that in preparation for the re-weld, a coworker had cleaned the interior of the drum with approximately a half cup of ethanol to remove suspected residual oil from earlier cutting and drilling. After cleaning the drum, he set it upside down to drain into a waste container used for ethanol waste and to evaporate. Approximately an hour later, he set the drum upright on a work cart to be welded. The mechanical technician knew the drum had been cleaned out with ethanol, but he believed the ethanol had been purged from it. He proceeded to re-weld the joints and held his tungsten inert gas (TIG) arc welder in his left hand over an opening in the container. The TIG welder ignited the ethanol vapor, causing a flash that contacted his left forearm.
A Laboratory investigative team was formed to review this event. The Tritium Science Engineering managers called a stand-down of shop operations to review procedures and housekeeping. Facility personnel are reviewing the following precautions for possible inclusion in facility safety practices.
- Development of procedures and requirements for designated welding areas. These would stress proper personal protective equipment and the need to always purge vessels before welding.
- Require a work instruction/checklist for cleaning and welding barrels so welders would know what has been done to the barrel before welding.
- Require workers to check with supervisors when they find abnormal conditions (e.g., cutting oil in the bottom of a barrel).
ANSI/ASC Z49.1-94, American National Standard for Safety in Welding, Cutting, and Allied Processes, provides guidance for performing welding and cutting operations safely. It states that when containers (drums and tanks) that have held flammable or hazardous substances are being welded or cut, there is the possibility of explosion, fire, or release of toxic vapors or fumes. Workers should also review ANSI/AWS F4.1, Recommended Safe Practices for the Preparation for Welding and Cutting of Containers and Piping. Additional standards for welder qualifications and inspections, as well as information on a wide variety of welding topics, are available from the American Welding Society (AWS). AWS standards have been adopted by ANSI. The Society’s URL is http://www.amweld.org/.
NFS has reported other events in the Weekly Summary where flammable materials came in contact with ignition sources. Some examples follow.
Weekly Summary 98-39 reported that a lubricant ignited when a mechanic at the Hanford Site sprayed it on a truck-mounted drill-head assembly he was repairing. The fire lasted less than 30 seconds and there were no injuries. Investigators believe that a static electric charge ignited the spray lubricant. The lubricant was an aluminum-complex-based grease that used butane, isobutane, propane, and hexane as propellants. (ORPS Report RL–PHMC-TANKFARM-1998-0117)
Weekly Summary 98-13 reported that two electricians at the Los Alamos National Laboratory Accelerator Complex received burns to their hands and faces when vapors from an aerosol electrical contact cleaner contacted an electrical space heater, ignited, and formed a fireball. They were using the cleaner while performing maintenance on electrical transformers. Investigators determined that use of the space heater was not specified in the work package, and they believe that no one had performed a chemical hazard analysis before the electricians began work. (ORPS Report ALO-LA-LANL-ACCCOMPLEX-1998-0005)
OEAF engineers also reviewed a final report this week that involved the ignition of flammable vapors. On December 29, 1998, at the Pantex Plant, a fire occurred when isopropyl alcohol vapors ignited while a production technician was using the alcohol to remove sealant material from a weapon component. The production technician quickly extinguished the fire with a fire extinguisher. Investigators believe the ignition source was either an electrostatic discharge or a frictional spark. They determined the root cause of the event to be a lack of controls that would have eliminated or reduced the potential for flammable alcohol vapor concentrations or possible ignition sources. The lack of controls included inadequate dissemination of information on isopropyl alcohol flammability. The Material Safety Data Sheet for isopropyl alcohol clearly calls attention to its flammability. Also, lessons learned from a similar flash fire involving isopropyl alcohol were not incorporated into the cleaning process. (ORPS Report ALO-AO-MHSM-PANTEX-1998-0094)
These events underscore the importance of ensuring that flammable materials and ignition sources are controlled and kept separate to prevent explosion or fire. In the case of welding, where the work involves the use of an ignition source, flammable materials should be kept away from the area. The safeguards should include purging containers of residual vapors and fumes that may be present following preparation work. When solvents, aerosols, and other flammable cleaners are being used, it is important to guard against the presence of an ignition source, such as an open flame, spark, friction, and electrostatic discharge. It is also important that workers are trained in the safe use of flammable materials. Facility managers should review their use of flammable cleaners and aerosol products and ensure that hazards associated with their use are evaluated and mitigated.
DOE O 440.1A, Worker Protection Management for DOE Federal and Contractor Employees, states that the contractor must identify workplace hazards and evaluate the risk of associated worker injury or illness.
DOE O 4330.4B, Maintenance Management Program, section 8.3.1, provides guidelines on work control systems and procedures. The order requires using control procedures to help personnel understand the requirements for working safely.
MINOR EXPLOSION DURING WELDING ACTIVITIES
On August 13, 1999, at the Sandia National Laboratory-Albuquerque, a subcontractor welder was welding materials for an elevator at the Process Environmental Technology Laboratory construction site when a minor explosion occurred. Emergency personnel, including the Kirtland Air Force Base Fire Department, an ambulance, and the site incident commander, responded to the scene. They determined that the blast was limited to the immediate area of the welding activity. Only the welder was injured, and ambulance personnel treated him for minor injuries, and transported him to a hospital. A Sandia representative issued a stop work order, established an exclusion zone around the elevator, and monitored the area for levels of volatile organic compounds. Sandia managers immediately initiated an investigation of the explosion. DOE representatives will closely monitor the investigation. OEAF engineers will provide additional information about the investigation as it becomes available. (ORPS Report ALO-KO-SNL-NMFAC-1999-0013)
FLASHBACK IN OXY-GASOLINE CUTTING SYSTEM RUPTURES OXYGEN LINE
On May 19, 1999, at the Hanford Site Inactive Facilities Surveillance and Maintenance Facility, a flashback occurred in the oxygen line for an oxy-gasoline cutting system when a decommissioning and decontamination (D&D) worker ignited the torch. The flashback ruptured and separated the oxygen hose at a point approximately 10 ft from the D&D worker and 50 ft from the gasoline tank. The worker was cutting on the north side of a 6-ft diameter, 5/8-in. steel pipe, and the rupture occurred on the south side of the pipe. A D&D worker who was on the south side of the pipe heard a loud crack and observed a road-flare-sized flame at the rupture. He quickly shut off the oxygen supply. No other personnel were within 10 ft of the burst, and no personnel were injured; however, a rupture closer to the D&D worker using the torch could have caused burns or other injury. (ORPS Report RL–BHI-IFSM-1999-0004)
The oxy-gasoline cutting system (Figure 4-1) consists of a standard oxygen cylinder, a pressurized 3-gal tank of unleaded gasoline, hoses, and a cutting torch. The tank delivers gasoline to the torch in liquid form, where it vaporizes and mixes with oxygen at the torch tip. Flashbacks on the fuel side are not possible because of the liquid state in the line. Also, a quick-close, high-flow valve at the gasoline tank immediately shuts off fuel if a line ruptures. The oxy-gasoline system offers several advantages over the standard oxy-acetylene cutting system, including safety, economy in fuel and labor-hours, longer tip life, faster burning, and little or no slag production.
The D&D workers immediately stopped work and notified their job supervisor. Investigators consulted the manufacturer’s technical manual. The manual recognizes that backflow of fuel into the oxygen line is possible under some circumstances. It recommends purging the oxygen line before igniting the torch and installing an additional flashback arrestor in the oxygen line at the torch. A field engineer received the same recommendations orally from a representative of the manufacturer, who also said that an incomplete purge of the oxygen line could cause a flashback. The system in use already had a flashback arrestor at the oxygen cylinder, as required by the manufacturer. Facility personnel installed a flashback arrestor on the torch and tested the system successfully. Additional corrective actions include incorporating the additional flashback arrestor into training and preparing a lessons learned bulletin for distribution to potentially affected sites.
This occurrence has been posted on the DOE Lessons Learned List Server. Visit http://www.tis.eh.doe.gov/ll/listserv.html for information on Lessons Learned List Server membership and access. Additional information on the oxy-gasoline system is available on the Web at http://www.fernald.gov/Technology%20Programs/lstd/oxy.htm, which describes the results of a technology demonstration conducted in 1996 by the DOE Fernald Environmental Management Project and Fluor Daniel Fernald.
PIPEFITTER CUTS STEAM LINE CHARGED WITH COMPRESSED AIR
On August 31, 1999, at the Pacific Northwest National Laboratory (PNNL), a pipefitter cut into a 3-inch carbon steel steam line that was pressurized with 100-psig compressed air. He immediately stopped cutting when he heard a hissing noise. The pipefitter, using a portable band saw, was performing demolition work on what he believed was an abandoned steam line. The pipefitter and his supervisor determined that the steam line was charged with compressed air. No one on the building core team, which consisted of the building manager, the facility project manager, and a work control specialist, knew that another organization had modified the abandoned steam line for use as an air supply line. Also, no one on the core team verified the status of the line before performing work. System modifications that are not adequately communicated to affected facilities may result in workers being exposed to unanticipated hazardous energy sources. (ORPS Report RL–PNNL-PNNLBOPER-1999-0027)
On September 1, 1999, the facility manager held a critique. Attendees determined that on May 5, PNNL managers approved a facility modification permit to remove abandoned steam and condensate lines from building 3760. In July 1999, the operating contractor discovered an underground leak in the plant air grid. In August, the operating contractor modified the abandoned steam line in building 329 to re-route 100 psig plant air around the leak in the plant air grid. This modification was performed before submitting an engineering change notice or obtaining PNNL authorization. The abandoned steam line served buildings 329 and 3760. They also determined that the PNNL building 329 manager, PNNL facility engineers, and the PNNL utility operations supervisor knew that the abandoned steam line was charged with plant air; however, no one notified the building 3760 core team of this. They also determined that the engineering change notice required cutting and capping the steam line to building 3760 and re-labeling charged sections of the abandoned steam line; however, this work was not yet done.
As a corrective action, the facility manager will develop a work release procedure form which will be used to release work and establish as-left conditions. The procedure will apply to facility and services work that is performed by workers outside of the core team. The facility manager will also apprise building managers, facility project managers, work control specialists, and plant engineers of the existing “300 Area Contractors Responsibility Procedure.” This procedure lists services points of contact and emphasizes the need for communication between organizations before beginning work.
NFS has reported other events involving issues of work control and communicating system status between different organizations at DOE facilities. Following are some examples.
· Weekly Summary 98-31 reported that during decommissioning, operations workers at the Oak Ridge National Laboratory East Tennessee Technology Park discovered that a lube oil system in a shut-down gaseous diffusion plant contained approximately 3,400 gallons of oil. Investigators determined that decommissioning contractor personnel believed that the lube oil system contained only residual amounts of oil because the previous contractor reported draining the system as part of deactivation. (ORPS Report ORO–BNFL-K33-1998-0003)
· Weekly Summary 96-18 reported that two pipefitters at the Savannah River Site were splashed with a 50-percent sodium hydroxide solution when cutting a transfer line from a tank. When the pipefitters made a cut in the pipe near a low point hidden by lagging, the sodium hydroxide spilled out causing minor skin irritation. The 30-foot pipe had a 3-inch dip near the middle that provided an area for solution to accumulate. Operators had drained and flushed the tank, but were unable to flush the transfer line. Although the Operations coordinator informed construction managers of these actions, the managers failed to inform the pipefitters. The event resulted from poor communication between operations and construction personnel, the industrial hygienists, and the work planners regarding the status of the transfer line. Investigators determined that supervisors did not identify the potential for residual solution in the line and did not discuss the hazards of caustic solutions. (ORPS Report SR–WSRC-FCAN-1996-0006)
These events illustrate the importance of ensuring that demolition work includes a thorough characterization of facility and equipment conditions. When planning work on or near abandoned systems or components, available documentation of the system’s status and usage may not be complete. When organizations outside of the facility organization perform work on interfacing systems, good communication and work control practices can prevent hazards associated with unforeseen system status and poor configuration control. The status of systems must be known to identify and mitigate hazards. Work release procedures are needed to ensure that operational and safety boundaries are maintained during the performance of work and that the status of the systems is known at the end of the work. Work that affects other organizations’ systems must be coordinated with those organizations and approved before the work is started. Before dismantling or segmenting any component, all hazardous energy sources to the component, e.g., air, water, steam, or electric power must be disconnected and a zero energy check must be performed.
This event also demonstrates the importance of multiple engineered barriers to prevent hazardous events. Although human performance (supported by procedures, policies, memoranda, or standing orders) is a standard barrier to pressurized component hazards, the probability of prevention can be increased by adding physical barriers such as lockouts and tagouts. Lockout/tagout program elements, such as zero energy checks, are described in 29 CFR 1910, Occupational Safety and Health Standards, and DOE O 5480.19, Conduct of Operations Requirements for DOE Facilities.
Facility managers should ensure that each new, existing, or modified system at their facility has been analyzed and managed in accordance with the core functions of DOE G 450.4-1, Integrated Safety Management System Guide. These core functions are as follows: define the scope of work, analyze hazards, develop and implement controls, perform work in accordance with controls, and integrate feedback and improvement. The guide states that the core functions, along with guiding principles, apply to the planning and performance of all types of potentially hazardous work, including construction, operation, and decommissioning. DOE-STD-1120-98, Integration of Environment, Safety, and Health into Facility Disposition Activities, provides guidance for enhancing worker, public, and environmental safety. It supports Integrated Safety Management System principles to guide the safe accomplishment of work activities. These principles include (1) line management responsibility for safety, (2) clear roles and responsibilities, (3) competence commensurate with responsibilities, (4) balanced priorities, (5) identification of safety standards and requirements, (6) hazard controls tailored to work being performed, and (7) operations authorization. Integrated Safety Management System information can be found at http://tis.eh.doe.gov/ism.
Welder Burned by Residual Cleaning Solvent; 7/28/00
Lesson Learned Statement:
Although welder safety training and welding procedures normally include prohibitions against allowing combustible/flammable material near welding operations, they may not specifically address the issue of flammable residue from cleaning solvents or oils. The introduction of combustible/flammable materials during cleaning activities was overlooked in this incident, resulting in personal injury to an experienced welder.
Discussion:
A Los Alamos National Laboratory mechanical technician operating a tungsten inert gas arc welder sustained first and second degree burns on his forearm and hand while modifying a stainless steel drum. He was transported to the local emergency room by a coworker, and subsequently referred to a burn and trauma center for outpatient treatment.
The technician had been assigned to reweld joints that had failed a helium leak detection test. A coworker cleaned the interior of the drum with ethanol to remove suspected oil residue and set the drum upside down to drain into a waste container. After it had drained and dried, the coworker set the cleaned drum upright on a work cart. The drums are not normally cleaned with ethanol, but the workers were concerned that residue from the first weld attempt might interfere with the second attempt to leak test the vessel. Neither the technician nor the coworker recognized that the cleaning activities could introduce unanalyzed hazards.
The technician did not purge the cleaned drum with an inert gas and did not inspect the drum to ensure it was clean and dry. He wore a welding smock and hood and cotton gloves during the job.
When the technician began welding, ethanol vapor ignited and vented through a hole in the drum, burning his forearm and hand. A worker across the hall heard a loud noise and entered the welding shop to investigate. The worker found the injured technician, who had turned the welding torch off and removed his smoldering glove.
Analysis:
The tube-to-vessel-fillet welding instruction the technician was using did not include a checklist of approved steps to complete fillet welds, and did not require purging . The Laboratory’s welding safety self-study course did not address cleaning containers using solvents or purging vessels and tubing as a safety precaution.
Recommended Actions:
Los Alamos national Laboratory revised welding training materials to include information regarding potential hazards associated with cleaning items to be welded and the use of purging as a safety precaution. The Laboratorey also took action ot ensure that welding instructions include appropriate purging requirements and cleaning precautions and is considering developing checklists for welding operations to help prevent the inadvertent introduction of unanalyzed activities.
Sparks from Grinding Cause Wildland Fire; 6/12/00
Lesson Learned Statement:
Dry brush and grass can be ignited easily by very minor sources. Extraordinary care must be exercised when welding, cutting, or grinding in wildlands
Analysis:
This fire could have caused considerably more damage had it been in heavier growth or a stronger wind been blowing. Proper fire prevention practices for cutting and grinding in a wildland area were not in place. Proper measures should include clearing or thoroughly wetting an area at least 35 feet around the hot work area, providing a fire watch, and assuring communications are available to report a fire.
Recommended Actions:
Anyone welding, cutting, or grinding must follow HNF-PRO-356, Controlling Hotwork. Fire protection engineers and fire department personnel are available to provide recommendations and guidance for identifying and minimizing danger from activities that could create flames, sparks, or other sources of ignition.
Vaporized Oil Flash Fire Burns Mechanic; 4/7/00
Lesson Learned Statement:
Even routine maintenance actions that have been performed many times can occasionally lead to accidents or injuries. Appropriate personal protective clothing, procedural precautions, and engineered safeguards should be employed to guard against all reasonable accident scenarios.
Discussion:
Two heavy-duty equipment mechanics were attempting to remove a gland nut (see figure 1) from the end of a leaking hydraulic lift cylinder while performing routine corrective maintenance on a man lift. They could not remove the gland nut using only mechanical methods so they applied heat with an oxyacetylene torch to release tension on the nut. Hydraulic fluid trapped between the leaking seal and the wiper seal vaporized, escaped from the leaking seal, and ignited from the heat of the torch. One employee received first and second degree burns on his right forearm from the vapor flash.
Analysis:
Similar repairs had been performed safely without incident hundreds of times in the past. In this case, the workers wore appropriate personnel protective equipment (PPE) for the job, however, the injured employee’s coverall sleeve was raised to the elbow exposing his bare forearm. Normal flexing of his arm apparently caused his sleeve to work up his arm while working. Full welder’s PPE was not prescribed since this was not welding.
When the workers encountered problems removing the gland nut, they stopped to consult another technical authority, determine a path forward, and agree on appropriate safety precautions. At no time was the possibility of the hydraulic fluid vaporizing and igniting identified as a hazard since no one involved in the job hazard discussion had previously experienced such an event or considered its possibility. All employees involved were experienced with this type of work and had many years of collective experience in this field.
Recommended Actions:
Wear full hot-work PPE, including fire retardant gloves with gauntlets and a face shield, when heating components.
Remove all potential fire hazards from the area before performing hot work.
Conduct periodic refresher training on hot work techniques and safety practices.
Include potential hazards identified in this lessons learned in the Automated Job Hazard Analysis hazard tree for hot work.
Fire Watch and Readily Available Fire Extinguisher; 3/26/98
Lesson Learned Statement:
The lack of a fire watch and/or a readily available fire extinguisher, with current inspections, are serious deficiencies.
Discussion:
While visiting two different projects being performed at the East Tennessee Technology Park (ETTP), a Department of Energy (DOE) Safety Engineer identified two separate welding/fire watch deficiencies. The first identified deficiency dealt with a subcontractor who was working on a structure located in a river. While he was welding, his fire watch walked off the structure, leaving him without a fire watch. Further investigation and discussion of the incident indicated the individual serving as fire watch had other duties he was performing while serving as fire watch. It was also noted that the fire watch did not have a fire extinguisher that was readily available on the structure. An extinguisher was available at the site; however, it was up the hill and across rough terrain on the river bank. This was a considerable distance from the site of the welding. The second identified deficiency dealt with personnel who were performing cutting operations, using a torch on hoppers approximately 10 feet above ground. The workers were using proper fall protection (safety harness with lanyard), wetting the work surface below as the cutting took place, wearing protection (welding sleeves and/or jacket), and wearing leather gloves when handling the metal sections. However, the fire watch did not have a fire extinguisher readily available for use. The workers were located on an elevated surface and the nearest fire extinguisher was approximately 40 feet away on the roof.
Analysis:
N/A
Recommended Actions:
* To resolve the first deficiency, the situation was discussed with the individual performing as the fire watch and the Safety Representative. It was agreed that a fire watch has one specific duty and should not be performing other aspects of the job. A fire watch trained laborer was to be reassigned to perform the function of fire watch. Also, a fire extinguisher with current inspection was to be maintained on site near any hot work operations and readily available for use. * To resolve the second deficiency, a fire extinguisher was secured to the scaffolding platform where it was readily accessible to the trained fire watch. * In both instances, the incidents were reviewed with the fire watch personnel to ensure they fully understood their duties and that they are responsible for having the appropriate fire extinguisher nearby in order to perform the fire watch function. * This lessons learned should be reviewed with all employees performing similar activities as a reminder of the responsibilities of all employees (including the fire watch) when performing this type of work.
Hot Slag Ignites Flexible Exhaust Duct at NRC Facility; 11/17/97
Lesson Learned Statement:
Timely identification by the fire watch of a fire started by hot slag while performing cutting and welding operations prevented serious injury to the welders.
Discussion:
On November 3, 1997, personnel at a commercial nuclear hot-cell facility reported a small fire in some flexible exhaust duct to the Nuclear Regulatory Commission. Facility personnel believe the fire started when a piece of hot slag fell on the duct during the cutting of some steel plates being removed from a decommissioned hot cell. A spokesperson for the facility reported that the fire watch extinguished the fire, and personnel evacuated the facility. The fire watch was later hospitalized overnight for smoke inhalation. Investigators determined there was no release of radioactivity to the environment and no damage to the facility. This event is important because of the increasing number of DOE facilities that are transitioning to deactivation and decommissioning activities, thereby increasing cutting and welding operations. (NRC Event Number 33204) A facility spokesperson reported that workers were cutting and removing steel plates in a decommissioned hot cell when hot slag from the cutting operation ignited the flexible exhaust duct. The spokesperson also reported that all smoke was filtered through the high efficiency particulate air filter ventilation system. The facility manager continues to investigate this event. This event illustrates the potential dangers involved in welding, cutting, and grinding activities. These activities pose safety and health hazards to workers under any circumstances, but they pose unique hazards to workers performing decontamination and decommissioning activities. Fire prevention is an important consideration for these activities. Open flames, electric arcs, hot metal, sparks, and spatter are ready sources of ignition.
Analysis:
N/A
Recommended Actions:
This incident emphasizes the important role the fire watch had by identifying the fire and notifying the welder. Employees are also reminded that prior to fighting a fire with a fire extinguisher, the fire department should be notified. If the fire cannot be contained, the area should be evacuated and left to the fire fighters. Managers at DOE facilities undergoing deactivation need to ensure that vendors and subcontractors understand local work control practices and the importance of following safety requirements. Several publications provide guidance on welding and cutting safety and on reducing fire and should be consulted by the appropriate facility personnel.
WELDING ACTIVITIES STOPPED BECAUSE OF SAFETY VIOLATIONS; 10/13/97
Lesson Learned Statement:
Continued attentiveness to safe practices and procedures during welding operations is essential.
Discussion:
On September 17, 1997, at the Savannah River Site, an Occupational Safety and Hygiene Department safety engineer observed several unsafe practices during welding operations at the Vitrification Treatment Facility and stopped the welding activities. The safety engineer was conducting an inspection of a construction area while a subcontractor performed welding activities in support of melter construction. He observed a number of safety violations, including fire watch violations; failure to use protective equipment; and combustible materials in the immediate area. Although these violations did not result in fires, personnel injuries, or fatalities, other welding and cutting events have resulted in these consequences. (ORPS Report SR–WSRC-RMAT-1997-0009) The safety engineer observed the following unsafe practices. · A welder wore a short-sleeved cotton T-shirt while welding. · A fire extinguisher was not readily available, and another fire extinguisher designated for welding operations had not been inspected and was missing the pull-pin. · The fire watch did not maintain a clear view of the work, did not have a fire extinguisher, and did not maintain the watch for 30 minutes after completion of the welding. · A welder used a tarp that was not flame-retardant for shielding.
Analysis:
N/A
Recommended Actions:
These events illustrate the potential dangers involved in welding, cutting, and grinding activities. Burns of the eye or body are also serious hazards of welding. To prevent these injuries, protective equipment appropriate to the specific welding activity should be worn. Welding shields and helmets protect workers’ eyes and faces from infrared or radiant light burns, flying sparks, metal spatter, and slag chips. Fire prevention is another important consideration. Open flames, electric arcs, hot metal, sparks, and spatter are ready sources of ignition. Many fires are started by sparks that pass through small openings such as cracks or holes. A fire watch, trained in the use of fire extinguishing equipment and the facilities available for sounding a fire alarm, is a necessary element of fire protection.
Welder Fatally Burned; 4/14/97
Lesson Learned Statement:
DOE established a Type A Accident Investigation Board to determine the causal factors and root causes of the welding/cutting fatality at the Oak Ridge East Tennessee Technology Park (formerly K-25 Site) on February 13, 1997.
See the Type A Investigation Report
DOE also disseminated preliminary accident investigation findings related to the flammability of anti-contamination clothing and the requirements for fire watches. DOE/EH-0550 Issue No. 971, March 1997 at http://tis.eh.doe.gov:80/docs/hha/hha_97_1.html
Discussion:
The accident at the Oak Ridge East Tennessee Technology Park involved a welder working outside a fixed shop area removing equipment from a facility in a high contamination area using an oxygen/acetylene cutting torch. Because the work was being performed in a high contamination radiological area, the welder was required to wear two layers of anti-contamination clothing, a full face respirator and a welder’s mask.
Sparks and/or molten metal (slag) from the cutting operations ignited the welder’s anti-contamination clothing. In this accident, fire consumed the clothing being worn by the welder in a very short period of time (approximately 3 minutes or less).
This accident illustrates the possibility that personal protective equipment can, by itself, create additional and often unrecognized worker hazards; in this case, the flammability hazard associated with the anti-contamination clothing. Thus, current jobs need to be reviewed for additional safety hazards that might be associated with the use of multiple controls or items of personal protective equipment.
-
-
flammability of the anti-contamination clothing
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worker’s inability to see that his clothing was on fire
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lack of a designated/dedicated fire watch for the operations
-
adequacy of the Job Hazards Analysis
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Slip, trip, or fall hazards associated with improper or loose fitting PPE; Rotating machinery entanglement hazards associated with the use of lab coats or other loose garments for protection against contamination or chemical spill hazard; Heat stress associated with multiple layers of clothing Vision impairments associated with loose fitting hoods, fogging goggles, etc.
Where such hazards are identified, the work controls should be modified either by using different personal protection equipment (e.g., non-skid anti- contamination shoe covers) to eliminate or reduce these unanticipated hazards or by introducing additional protection against the new hazards.
Analysis:
Contributing factors to the accident:
Recommended Actions:
Actions taken by Lockheed Martin:
All Lockheed Martin Energy Systems managers must ensure that active permitted work and related hazards analysis and controls have been reviewed for additional hazards associated with the use of multiple controls or items of personal protective equipment. Safety and Health and Rad Con field support personnel are available to assist in this review.
A memorandum confirming that existing permitted work and hazards analyses have been reviewed for unidentified hazards must be submitted by April 30, 1997. This memo should identify the number of jobs reviewed and the number in which previously unidentified hazards were identified.
Cool Vest Liquid Ignited By Contact with Portable Welder Exhaust Pipe; 9/18/00
Lesson Learned Statement:
Material Safety Data Sheets should be reviewed carefully by personnel who understand the terminology used and the work that will be performed.
Discussion:
At the East Tennessee Technology Park a worker placed a Phase Change Cooling System (PCCS) vest, on top of a gasoline engine powered welder that had recently been in use. The vest inadvertently came in contact with the exhaust pipe, which was still warm. The contact melted the vest cover and when the fluid in the vest flowed out, it ignited.
Analysis:
The MSDS for the vest (which covers PCCS Phase 1 Vest-FR, PCCS Phase 2A Vest-FR, PCCS Phase 2B Vest-FR, and PCCS Cooling Packs 1 and 2, all manufactured by OccuNomix International Inc.) states that the material used inside the vest has a flash point of 275 F, that the LEL flammability and UEL flammability limits are not available, and that the autoignition temperature is “greater than 400F.” The sheet further states that there is no unusual fire and explosion hazard. A caution note included with the information package states that “although product is non-flammable, non-toxic, and non-carcinogenic, it may cause skin irritation.” The ingredients in the vest are listed as: n-Hexadecane (95-98%), n-Tetradecane (<2%), 3-methylpentadecane (<2%), 5-methylpentadecane (<2%), 7-methylpentadecane (<2%), and n-Octadecane (<2%).
Hexadecane, the primary ingredient, is a Class IIIB liquid, which means that its flash point is greater than 200F. OSHA places no special controls on Class IIIB liquids because they pose little to no risk in a normal work environment. However, in areas in which surfaces or open flames are at a temperature greater than the liquid’s flashpoint, they can pose a significant risk to the user. The ETTP Project found that when inflammable material is soaked with the contents of the cool vest, the material burns freely. If a person were to come into contact with open flames, such as from a plasma torch, while wearing the vest, the consequences could be severe.
Recommended Actions:
East Tennessee Technology Park management took the following actions:
Ban the use of these vests in the immediate vicinity of extreme heat sources (such as exhaust pipes) and ban the use of the vests within 25 feet of hot work activities.
Evaluate PPE during task definition against the hazards posed by the actual task, using the MSDS for reference.
Trailer Set On Fire by Cutting Torch; 3/28/00
Lesson Learned Statement:
Identify hazards and ensure proper controls are in place prior to starting work.
Discussion:
Two employees (a construction mechanic and a senior engineer) at the Nevada Test Site were using a cutting torch to remove components from an excessed motorized trailer. During the cutting, sparks and slag ignited some insulation on the trailer. One of the employees attempted to extinguish the fire; however, the fire extinguisher was previously discharged and ineffective. The fire grew until a gasoline line on the trailer was severed. The gasoline tank on the trailer was empty, but the line had some residual fuel which continued to burn. The fire department was called and quickly extinguished the fire.
Analysis:
The fire extinguisher on the employee’s vehicle was not serviced within the time frame required, and had been previously discharged but the employee did not know this. Only one fire extinguisher was available in close proximity to the incident scene. Cutting on the motorized trailer constituted a ‘modification’ to it. At least one of the employees involved had been instructed not to make any modifications to that trailer without input from the vehicle and equipment maintenance personnel so that all hazards could be identified and the work assigned to the appropriate craftsmen. Procedures were in place that required fire extinguishers to be recharged after use. Fire extinguisher training is conducted annually.
Recommended Actions:
Ensure work controls are in place and hazards are analyzed and reviewed by other groups who can offer valuable input for hazard controls. Perform inspections of safety equipment according to inspection schedules and prior to starting an activity to ensure they are fit for use. Maintain fire extinguishers in a ready state and inspect them frequently.
PVC Pipe Explosion; 10/10/95
Lesson Learned Statement:
Fumes from PVC pipe glue can accumulate inside closed piping systems and can produce explosive hazards.
Discussion:
SUMMARY:
A 15.24 cm (6″) PVC pipe exploded while an attached steel pipe was being cut by a torch. About 100 meters (300 feet) of pipe exploded sending shrapnel throughout the building. Two people were sent to the hospital for minor cuts.
DETAILS:
Lorin Industries was building a new pipe line from all new plumbing. One end of the 15.24 cm (6″) PVC pipe was connected to a steel pipe which was connected to a cooling return pump. The other end was plugged. The PVC pipe had been glued together approximately 3 weeks prior to the incident.
The contractor was using a torch to cut a hole into the steel pipe to attach a sensor when the entire section of PVC pipe exploded. Shrapnel spread over the entire 122 meter x 67 meter (400′ X 220′) building. There were about 40 people standing under the pipe at the time of the explosion. Two people were sent to the hospital for minor cuts.
The individual from Lorin Industries writing this report did not know the cause of the explosion. He requested anyone with expertise in this area to respond. Mr. Robert N. Nelson, Chemistry Dept., Georgia Southern University, Landrum Box 8064, Statesboro, GA 30460-8064 replied to Lorin Industries with his following personal opinion. Georgia Southern University disclaims any position on this subject matter.
Analysis:
The adhesives used in assembling the PVC pipe contain a variety of volatile solvents. With a 15.24 cm (6 in.) pipe a significant amount could be trapped in the joint and only volatilize over a period of time. Mr. Nelson suspects that the vapors accumulated causing an explosive mixture in the sealed pipe.
Recommended Actions:
Ventilate newly fabricated PVC pipes before performing any spark producing activity around them.
Oxygen Hazards; 11/1/99
Lesson Learned Statement:
Improper use of oxygen (e.g. spraying it on clothing or body parts for cooling) can result in serious injuries or death.
Discussion:
During the past several months three employees of McDermott International, Inc. were burned while improperly using oxygen.
In the first case an employee intentionally put the nozzle of an unlit cutting torch in his pants with the oxygen valve open. As soon as he re-lit the torch, the heat from the flame ignited his pants, causing severe burns to his body below his belt line.
The next incident occurred inside a small space located in a steel enclosure where a worker had been cutting with a torch. The worker turned off the gases with the valves on the torch before exiting the workspace. As he was lighting the torch after returning to the job, a minor explosion resulted in a short flash fire that severely burned the employee. The oxygen valve on the torch had not been fully closed, permitting oxygen to accumulate in the small space.
Most recently, an employee squirted oxygen into his glove to cool his hand. Sparks from a nearby metal saw being operated by a fellow worker ignited the glove, severely burning the torch bearer’s hand.
Analysis:
Pure oxygen supports rapid combustion of any burnable material. Materials in the presence of an enriched oxygen atmosphere can ignite with little warning. Oxygen must never be used for any purpose other than intended.
Recommended Actions:
Anyone working with or near oxygen should exercise extraordinary caution, especially when ignition sources are present. It can easily result in significant safety hazards when used improperly.
BRIEF DESCRIPTION OF ACCIDENT
A laborer was killed when a gasoline storage tank he was cutting with a portable power saw exploded. The worker’s company was involved in installing, removing and junking gasoline pumps and underground tanks. Although he had experienced working with the saw and scrap materials, the worker did not adequately purge the tank and test for vapors before beginning to cut. The 18 x 6 foot, 3000 gallon tank had been used recently for underground storage at a service station. At the time of the explosion, the mechanic was cutting on the tank with a gasoline powered portable saw equipped with an abrasive epoxy disk for cutting metal. The explosion propelled the worker 10 to 15 feet from the tank into another tank.
ACCIDENT PREVENTION RECOMMENDATIONS
Train employees to recognize and avoid unsafe conditions when working with tanks that have previously contained flammable liquids (29 CFR 1926.21(b)(2)).
Follow recommended procedures set forth in American Petroleum Institute (API) Bulletin 1604, “Recommended Practice for Abandonment or Removal of Used Underground Service Station Tanks”.
Test atmosphere in tank prior to work or cutting.
Establish guidelines for gas-freeing.
BRIEF DESCRIPTION OF ACCIDENT
A welder entered a steel pipe (24 inch diameter) to grind a bad weld at a valve about 30 feet from the entry point. Before he entered, other crew members decided to add oxygen to the pipe near the bad weld. He had been grinding intermittently for about five minutes when a fire broke out enveloping his clothing. Another crew member pulled him 30 feet to the pipe entrance and extinguished the fire. However, the welder died the next day from his burns.
INSPECTION RESULTS
Following its inspection, OSHA issued three citations one willful, one serious and one repeat. Had the cited standards been followed, this fatality might have been prevented.
ACCIDENT PREVENTION RECOMMENDATIONS
Do not use oxygen for ventilation, cooling or cleaning in welding operations (29 CFR 1926.353(a)(b).
Comply with OSHA’s required confined or enclosed space entry program (29 CFR 1926.21(b)(6)(i)).
Train employees to recognize and avoid unsafe conditions associated with their work and make sure they understand the confined space entry program and follow its procedures (29 CFR 1926.21(b)(2) and 1926.20(b)(1)).
SOURCES OF HELP
“Occupational Fatalities Related to Fire and/or Explosions in Confined Work Spaces as Found in Reports of OSHA Fatality/Catastrophe Investigations,” available from the National Technical Information Service, 5285 Port Royal Rd., Springfield, Va. 22161, (703) 587-5650, publication no. PB 82-237-314, $13.00, pre-paid.
Construction Safety and Health Standards (OSHA 2207) which contains all OSHA job safety and health rules and regulations (1926 and 1910) covering construction.
OSHA-funded free consultation services. Consult your telephone directory for the number of your local OSHA area or regional office for further assistance and advice (listed under U.S. Labor Department or under the state government section where states administer their own OSHA programs).
BRIEF DESCRIPTION OF ACCIDENT
Two employees were welding brackets onto an oil storage tank (55,000 gallons). The tank, half full, contained explosive atmospheres of vapor from waste chemical and oil materials from automobile and truck service stations. One worker was killed and another injured when the tank exploded and the top was blown off.
INSPECTION RESULTS
As a result of its investigation, OSHA issued citations for violations of four standards.
ACCIDENT PREVENTION RECOMMENDATIONS
The employer must instruct each employee in the recognition and avoidance of unsafe conditions and the regulations applicable to his work environment “to control or eliminate any hazards [29 CFR 1926.21(b)(2)].
The employer is responsible for requiring the wearing of appropriate personal protective equipment in all operations where there is an exposure to hazardous conditions [29 CFR 1926.28(a)]. In this case, safety belts and lanyards or other means of fall protection would have prevented employees from falling off the tank to the ground. Also, fire or heat resistant safety clothing should have been provided and used.
Welding, cutting, or heating must not be done where the application of flammable paints, or the presence of other flammable compounds, or heavy dust concentrations creates a hazard [29 CFR 1926.352(c)].
Drums, containers, or hollow structures which have contained toxic or flammable substances must be filled with water or cleaned of such substances and ventilated and tested before welding, cutting, or heating is undertaken on them [29 CFR 1926.352(i)].
SOURCES OF HELP
OSHA General Industry Standards [29 CFR parts 1900-1910] and OSHA Construction Standards [29 CFR Part 1926] which together include all OSHA job safety and health rules and regulations covering construction.
OSHA-funded free consultation services listed in telephone directories under U.S. Labor Department or under the state government section where states administer their own OSHA programs.
Courses in construction safety are offered by the OSHA Training Institute, 1555 Times Drive, Des Plaines, IL 60018, 312/297-4810.