LoC: DEGRADATION

The wall of the kiln collapsed when 3 workers were inspecting the kiln furnace

Proximate causes:
• Inadequate tools, equipment & vehicles
• Inadequate training/knowledge transfer (Lack of understanding the process of the calcination of limestone);
• Lack of work rules/policies/ standards/procedures (lack of standard procedures for inspections);
• Inadequate work rules plan (lack of the pre-start safety review before inspection).

Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)
Image Credit: Wikipedia

A fire on one of the Royal Navy’s latest guided missile destroyers has killed eight men. The £23m HMS Glasgow was being fitted out at a shipyard near Newcastle-upon-Tyne, north-east England, and was due to start sea trials shortly.

It is thought the fire at Swan Hunter’s Neptune yard was started by a welder’s torch after gas had been leaking from an oxygen cylinder. Six other shipyard workers were also injured in the blaze. Survivors reported hearing an explosion before the fire took hold and spread rapidly to three decks of the ship.

A Health and Safety Executive investigation confirmed oxygen, which had been leaking all night from a supply line, helped cause a fire to be ignited by a welder’s torch and burn more fiercely than normal. The HSE blamed Swan Hunter Shipbuilders for not ensuring the oxygen pipes had been disconnected the previous evening. But it also said ship workers failed to notice signs of leaking oxygen espite references in safety manuals and a film shown three times at the yard. The report also recommended designers consider providing alternative methods of escape from ships during their construction.

HMS Glasgow was commissioned three years later and is on active naval service.

A fire started in a 5000-L tank at the Milazzo refinery, which is jointly owned by Italy’s Eni and Kuwait Petroleum. Firefighters controlled the fire but the tank burned until the oil tank was empty. According to the fire department, the fire was caused by the collapse of the tank roof.

Proximate causes:
• Inadequate work planning
• Inadequate maintenance (local media reported that when the refinery caught fire, there was maintenance work going on at the facility)
• Inadequate management/ supervision

Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)
Image Credit: RT

On October 2, 2007, a chemical fire inside a permit-required confined space1 at Xcel Energy’s hydroelectric plant in a remote mountain location 45 miles (72 kilometers) west of Denver, Colorado, killed five and injured three workers. Industrial painting contractors were in the initial stages of recoating the 1,530-foot (466-meter) steel portion of a 4,300-foot (1,311-meter) enclosed penstock2 tunnel with an epoxy coating product when a flash fire occurred. Flammable solvent being used to clean the epoxy application equipment in the open penstock atmosphere ignited, likely from a static spark. The initial fire quickly grew as it ignited additional buckets of solvent and substantial amounts of combustible epoxy material, trapping and preventing five of the 11 workers from exiting the single point of egress within the penstock. Fourteen community emergency response teams responded to the incident. The five trapped workers communicated using handheld radios with co-workers and emergency responders for approximately 45 minutes before succumbing to smoke inhalation.

KEY ISSUES:
• SAFE LIMITS FOR WORKING IN CONFINED SPACE FLAMMABLE ATMOSPHERES
• PRE-JOB SAFETY PLANNING OF HAZARDOUS MAINTENANCE WORK
• CONTRACTOR SELECTION & OVERSIGHT
• EMERGENCY RESPONSE AND RESCUE

ROOT CAUSES:
1. Xcel and RPI management did not ensure effective planning and coordination of the Cabin Creek penstock recoating project to control or eliminate the serious confined space hazards that were present.
2. Xcel’s and RPI’s corporate safety policies and permits did not effectively establish safe limits for flammable atmospheres in permit-required confined spaces that would prohibit entry or occupancy when those limits were exceeded.
3. Early in the planning process, Xcel identified the Cabin Creek penstock’s single point of egress in the event of an emergency as a major concern; RPI personnel also raised safety issues about a single exit. However, neither Xcel nor RPI management took remedial action.
4. Xcel management did not provide effective oversight of RPI to ensure the penstock recoating work was safely conducted.

Image credit: CSB

An explosion originating in the hydrogen processing unit occurred in this 75,000 bbl/d refinery. Extensive damage was caused to the hydrocracker, hydrodesulphurization, and hydrogen processing units by the explosion and subsequent fires. The fires were fuelled by hydrocarbons released from the damaged process column and equipment. The explosion, which damaged nearby buildings and shattered windows several miles away, was recorded as a ‘sonic boom’ at the California Institute of Technology in Pasadena, approximately 20 miles from the refinery.

The explosion resulted from the rupture of a the outside radius of a six-inch-diameter carbon steel 90° elbow and the release of a hydrocarbon-hydrogen mixture to the atmosphere. The vapor cloud ignited within seconds of the rupture. There were no out-of-range or warning indications relevant to the incident until after the failure of the pipe elbow. An inspection after the failure found the line at nearly full design thickness a short distance away from the failure. On these facts, it was concluded that the line failure was the result of the thinning of the carbon steel elbow due to long-term erosion/corrosion. The fire-fighting effort was coordinated by the refinery emergency response team, with the Los Angeles City and Los Angeles County Fire Departments utilizing the Joint Incident Command System. The refinery emergency response team placed booms in the Dominguez Channel storm drain to stop oily water run-off generated by the fire fighting effort from reaching the Los Angeles Harbor. The fire was finally extinguished after three days. The refinery’s gasoline production was reduced to 35,000 bbl/d (approximately 70% of rated capacity) until repairs to the damaged process units were completed.

[ Property Damage $78 Million. Estimated Current Value $165 Million ]

Image credit: Tesoro

The fire on the vacuum distillation unit (VDU) weakened the main vacuum distillation column supports, allowing it to collapse onto the heat exchange train. The VDU was shutdown completely and the refinery was left running but at a much reduced capacity. An investigation identified that the fire was caused by a leak from a branch on the column that was fabricated from an incorrect material.

[ Property Damage $143 Million. Estimated Current Value $191 Million ]

Image credit: ORLEN

An explosion and subsequent fire resulted in significant property damage at this 146,500 bbl per day refinery. The explosion occurred following a heat exchanger failure in the hydrodesulphurization unit for light oil. The channel cover and lock ring of this heat exchanger were hurled into an adjacent factory, which was located approximately 650 feet from this plant. The channel cover and lock ring were each five feet in diameter, and weighed 4,000 lb and 2,000 lb, respectively. The hydrodesulphurization unit was being restarted following catalyst exchanging work when plant personnel noticed that hydrocarbon was being released from the heat exchanger. Plant personnel were working to complete the additional tightening work required on the heat exchanger bolts due to thermal expansion when the explosion occurred. The subsequent fire was brought under control in two hours and 45 minutes by firefighters using 15 fire trucks.

[ Property Damage $161 Million. Estimated Current Value $339 Million ]

Image credit: FOC

On Monday, October 17, 2016, there was an explosion and subsequent fires at the North Harbor in Ludwigshafen. “We mourn two colleagues from the fire department and the seaman who died in the fire. Our deepest sympathy is with their families and friends. Many people were injured, some of them severely. Our thoughts are with them and their families and friends. We hope that they are on the way to recovery,” said Dr. Kurt Bock, Chairman of the Board of Executive Directors of BASF at a press conference in Ludwigshafen, Germany.

The following information is currently known about the accident:

Victims: Two employees of the BASF fire department and an employee of a tanker which was anchored in the harbor died in the accident. Eight people were seriously injured, 22 others were slightly injured. One of the seriously injured has been released from the hospital.

Course of events: The course of events is still being investigated by the public prosecutor’s office of Frankenthal. The incident site is still locked. A few days prior to the accident, a specialized pipeline construction company began to conduct assembly works on a deflated and secured ethylene pipeline route. The aim of the assembly works was to exchange several parts of the pipeline as a preventive maintenance measure. On October 17, a fire started at 11:30 a.m. near the assembly works. Forces of the BASF fire department, emergency service and environment protection arrived a few minutes later at the incident area and immediately started emergency operations. During the initiation of emergency operations an explosion, most likely at the ethylene pipeline, occurred. The explosion led to subsequent fires at various points along the pipeline trench, damaging further product and supply pipelines. Additional emergency forces immediately began rescue measures as well as extinguishing and cooling measures. “The emergency forces operated in an extreme situation. Their effort cannot be expressed in words,” said Margret Suckale, Member of the Board and Site Director of Ludwigshafen.

The fire brigade performed controlled burning of the leaking products in accordance with the fire-fighting concept for compressed gases. The pipelines that burned included those used for ethylene, propylene, a butylene product mix (raffinate), pyrolysis gasoline and ethylhexanol. As of October 17, 9.30 p.m., the emergency forces extinguished the fire.

Environmental impact: Following the start of the fire, comprehensive air measurements were conducted at the site gate and in areas surrounding the site in Ludwigshafen and Mannheim. The measurements showed no elevated levels of hazardous substances, as confirmed by the environmental ministry of Rheinland-Pfalz and the city of Ludwigshafen. Additional measurements conducted by the cities of Speyer, Worms and Frankenthal showed no elevated levels. Elevated levels measured locally were restricted to the immediate area of the incident. BASF has published the results of the air measurements as well as an overview map online. Water samples also showed no elevated levels of hazardous substances. A contamination of the ground at the incident site is likely.

Status of the investigation: On October 26, the District Attorney of Frankenthal/Palatinate and the Police Headquarters of Rheinpfalz announced the following information on the progress of the investigation:

“In the course of intensive investigations directly at the scene of the incident, it has been established that there was a cut made in a pipeline. This was apparently done with a cutting disc. Maintenance work using an angle grinder was in progress on an adjacent pipeline. The cut pipeline was not part of this work. This pipeline contained flammable raffinate.” (Excerpt of the press release from District Attorney of Frankenthal/Palatinate and the Police Headquarters of Rheinpfalz, translated by BASF).

According to the current, preliminary evaluation, this could be the chain of causes: The cut pipeline contained a butylene mixture. BASF assumes that this butylene mixture leaked out and ignited due to the sparks produced by the angle grinder. This could have led to the fire, which caused the described explosion. BASF will continue to support the relevant authorities during the investigation into the cause of the accident.

Source: BASF (https://www.basf.com/global/en/media/news-releases/2016/10/p-16-359.html) | Image Credit: Reuters

​On October 17, 2016, shortly after 9:00 p.m. local time, an 8-inch-diameter underground transmission pipeline ruptured and released 2,587 barrels (108,654 gallons) of liquid anhydrous ammonia on private property adjacent to milepost (MP) 263.32 on County Road P in Burt County, near Tekamah, Nebraska. The pipeline was owned and operated by Magellan Midstream Partners, LP, (Magellan). Upon release and exposure to the atmosphere, the ammonia vaporized and produced a toxic plume. A local resident who had left his home to investigate the accident scene died of respiratory failure due to exposure to the ammonia vapor; additionally, two people sustained minor injuries. A total of 29 households, involving 49 people, were evacuated. U.S. Highway 75, a main roadway in the area, was closed for several days.

The ammonia pipeline was operated and monitored from a control center located in Tulsa, Oklahoma. Low pressure alerts were received in the control center at 9:03 p.m., and a rupture alarm first occurred at 9:14 p.m.At 9:21 p.m., control center personnel received a third-party report of strong ammonia odor and a vapor cloud located 8.5 miles north of Tekamah, Nebraska.

Image Credit: NTSB

An explosion occurred while polypropylene polymerization was being carried out in three parallel reaction trains (A,B,C) at this petrochemicals plant. The reactants were carried in a hexane solvent with several catalysts and processed onto pellets. As a result of a maintenance error, a 100 millimetre plug valve was blown out of a line in train A, releasing hydrocarbons and polymers. The vapor cloud rose upward, carried by a light wind into the finishing building, where the explosion occurred. Further fires resulted from broken flammable liquid lines in the process area and from the released products in the finishing area. The loss included the three trains, the control building, the compressor building, and part of the finishing building.

[ Property Damage $45 Million. Estimated Current Value $147 Million ]

Image credit: Leo S. Matkins

A chemical spill shut down portions of Interstate 75 in northern Madison County. A tanker truck was leaking ferric chloride solution from one of its valves

Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)
Image Credit: WKYT

At approximately 1:00 p.m. on the 23rd October 1989 Phillips’ 66 chemical complex at Pasadena, near Houston (USA) experienced a chemical release on the polyethylene plant. A flammable vapour cloud formed which subsequently ignited resulting in a massive vapour cloud explosion. Following this initial explosion there was a series of further explosions and fires.

The consequences of the explosions resulted in 23 fatalities and between 130 – 300 people were injured. Extensive damage to the plant facilities occurred.

The day before the incident scheduled maintenance work had begun to clear three of the six settling legs on a reactor. A specialist maintenance contractor was employed to carry out the work. A procedure was in place to isolate the leg to be worked on. During the clearing of No.2 settling leg part of the plug remained lodged in the pipework. A member of the team went to the control room to seek assistance. Shortly afterwards the release occurred. Approximately 2 minutes later the vapour cloud ignited.

KEY ISSUES:
• MAINTENANCE PROCEDURES
• LEAK / GAS DETECTION
• PLANT LAYOUT
• PERMIT TO WORK SYSTEMS
• ACTIVE / PASSIVE FIRE PROTECTION
• WARNING SISGNS
• EMERGENCY RESPONSE / SPILL CONTROL

Image Credit: Houston Chronicle

A fire broke out at the SRC at around 1.30 pm on 25 October 1988. It was the refinery’s second major fire; the first occurred on 16 August 1984. Even though the 1988 fire did not claim any lives, it injured 25 people, mostly firefighters, including five who were seriously hurt.

The fire lasted about five days before it was completely extinguished at about 7 am on 30 October. Damages, loss of profit, loss of raw materials (especially naphtha) and construction costs of new tanks were initially estimated by insurers to be between S$15 and S$20 million. In November 1988, then Director of the Singapore Fire Service Arthur Lim estimated damages to be around S$30 million. The fire and temporary closure of SRC caused the price of naphtha to rise by US$15 per tonne in the Far East.

Ref: https://eresources.nlb.gov.sg/infopedia/articles/SIP_1007_2010-05-07.html
Image Credit: SCDF

At about 1.25 am on the fourth of November 1975 the foreman at the Queen Victoria Blast Furnace, Appleby-Frodingham Works started a cast that was intended to fill two torpedo ladles. Conditions at the time were normal; the shift manager was in attendance.

Shortly before 2.00 am some 175 tonnes of metal had been run into the first torpedo and the iron stream diverted to the second ladle. Some 10 to 15 minutes later the blow pipe at the No. 3 tuyere position started to burn down on the side facing on to No. 2 tuyere hearth cooler. The burning developed rapidly with intense flame and sparks despite efforts by the furnace keeper to cool the pipe by spraying it with water.

Whilst the pipe was burning down, a substantial water leak from the furnace or fittings was observed. The source of the leak could not be identified because the face of the furnace was obscured by flame. For the same reason men could not approach the leak to take remedial action. The leak of water was under pressure and fell outwards from the furnace towards the edge of the hob; from the hob the water ran down the slope of the cast house floor joining eventually with the iron runnel Water entered the full torpedo ladle.

Within a few minutes of the blow pipe starting to burn down progressive action was being taken by the furnace crew to bring the furnace off blast so that a new pipe could be fitted.

Shortly before 2.47 am instructions from the shift manager were passed via Traffic Control to a loco driver and shunter to remove the full torpedo ladle from the vicinity of the furnace. Traffic personnel were made aware that water was running into the torpedo. As the loco was coupled to the ladle, water was seen to be coming from the iron runner. An explosion occurred as the ladle was moved. An eye witness identified the throat of the ladle as the seat of the explosion. The incident was timed at 2.47 am.

As a result of the explosion there were four immediate fatalities and 15 hospital admissions. Subsequently a further seven employees died as a result of injuries received.

At the time of the explosion 23 persons were working in the Queen Victoria furnace area. This number included four extra helpers standing by to assist in changing No. 3 blast pipe. Casting to the second torpedo was sti11 proceeding at the time of the explosion.

Report: https://www.icheme.org/media/13691/the-explosion-at-appleby-frodingham-steelworks-scunthorpe.pdf

Image Credit: HSE

Offshore gas alarms were triggered on this floating production unit. Upon investigation, it was established that a leak was emanating from one of the production risers. Upon further investigation, five other risers were found to be similarly affected. Remedial work was subsequently carried out.

[ Property Damage $185 Million. Estimated Current Value $248 Million ]

Image credit: No credit

The Valero Delaware City refinery asphyxiation death of two contractor employees who were preparing to reassemble a pipe on a pressure vessel while it was being purged with nitrogen. The first worker, in an attempt to retrieve a roll of tape from inside the vessel, was overcome by nitrogen, collapsed in the vessel, and died. His co-worker, the crew foreman, was asphyxiated while attempting to rescue him.

KEY ISSUES:
• OXYGEN-DEFICIENT ATMOSPHERE HAZARDS OUTSIDE CONFINED SPACE OPENINGS
• NITROGEN HAZARD AWARENESS
• UNPLANNED CONFINED SPACE RESCUE

ROOT CAUSES:
1. Workers suddenly involved in emergency activities allow emotions to override safe work procedures and training.

Image credit: CSB

November 9, 2010 explosion at an E.I. duPont de Nemours and Co. Inc., Yerkes chemical plant in Buffalo, New York when a contract welder and foreman were repairing the agitator support atop an atmospheric storage tank containing flammable vinyl fluoride. The welder died instantly from blunt force trauma, and the foreman received first-degree burns and minor injuries. The explosion blew most of the top off the tank. The top and agitator assembly hung over the side of the tank supported only by a 2-foot section of the top (cover photo). The explosion caused minor overpressure damage in the tank farm area and the adjacent production building.

KEY ISSUES:
• FLAMMABLE GAS MONITORING
• TANK ISOLATION
• HOT WORK PERMITS, PROCEDURES & SIGN-OFFS

ROOT CAUSES:
1. All potential explosion hazards associated with hot work activities not identified and mitigated
2. All relevant forms required for permits not completed in accordance with corporate policies and industry standards (including NFPA 326 and NFPA 51B)
3. Appropriate DuPont personnel did not officially approve hot work permits, by signature or equivalent, consistent with DuPont policies

Image credit: CSB

A vapor cloud explosion occurred in the gas plant associated with the 29,700 bbl/d FCC unit on a 136,000 bbl/d refinery. The initial vapor cloud explosion and several subsequent lesser explosions could be heard in Marseille, approximately 18 miles from the refinery. An estimated 11,000 pounds of light hydrocarbons were involved in the initial explosion. A gas detection system in the FCC unit sounded an alarm indicating a major gas leak. While the unit operator was contacting the security service to warn of this situation, the initial explosion occurred. The initial gas release is believed to have resulted from a pipe rupture in the gas plant, which was used to recover butane and propane produced in the FCC unit. The explosions and subsequent fires devastated about two hectares of this refinery, which covers an area of about 250 hectares. The gas plant, FCC unit, and associated control building were completely destroyed by this incident. Two new process units, which were under construction and scheduled to come into operation in 1993, were seriously damaged. Outside of the refinery, roofs were damaged in the nearby town of Chateauneuf les Martigues and windows were broken within a radius of 3,000 feet. Some windows were broken up to six miles away.

The refinery fire brigade and more than 250 fire fighters from three neighboring industrial sites and four nearby towns were used for more than six hours to bring this incident under control. Approximately 37,000 US gallons of foam concentrate were used during the fire fighting effort. Some fires were intentionally left burning after the incident was under control to allow safe depressurizing of the process units since the flare system was partially damaged by the explosions.

Click to access FD_3969_La_Mede_1992_ang.pdf

[ Property Damage $225 Million. Estimated Current Value $474 Million ]

Image credit: Total

On November 12, 2008, a 2-million-gallon liquid fertilizer tank (designated as Tank 201 by the owner) catastrophically failed at the Allied Terminals, Inc. (Allied) facility in Chesapeake, Virginia, seriously injuring two workers and partially flooding an adjacent residential neighborhood.

On the day of the incident, Allied was filling Tank 201 with liquid fertilizer to check for leaks prior to painting the tank. During the filling, a welder and his helper sealed leaking rivets on the tank.

At a fill level about 3.5 inches below the calculated maximum liquid level, the tank split apart vertically, beginning at a defective weld located midway up the tank. Within seconds, the liquid fertilizer overtopped the secondary containment, partially flooding the site and adjacent neighborhood. The collapsing tank wall injured the welder and his helper, who were working on the tank. Employees of a neighboring business responded and extricated them. At least 200,000 gallons of the liquid fertilizer were not recovered; some entered the southern branch of the Elizabeth River.

KEY ISSUES:
• LIQUID FERTILIZER STORAGE TANK STANDARDS
• TANK MODIFICATION FOR CHANGE-IN-SERVICE
• TANK INSPECTION

ROOT CAUSES:
1. Allied did not ensure that welds on the plates to replace the vertical riveted joints met generally accepted industry quality standards for tank fabrication.
2. Allied had not performed post-welding inspection (spot radiography) required for the calculated maximum liquid level for the tank.
3. Allied had no safety procedures or policies for work on or around tanks that were being filled for the first time following major modifications and directed contractors to seal leaking rivets while Tank 201 was being filled to the calculated maximum liquid level for the first time.

Image credit: CSB

Chemical leak at a metal recycling plant. Firefighters sealed the valve and dispersed the vapor cloud. Two workers were treated at the scene as a precautionary measure

Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)
Image Credit: BBC

On Friday 19 November 2010 at 3:45pm there was an underground explosion at the Pike River coal mine. Twenty-nine men lost their lives, and their bodies have not been recovered.

Two men survived the explosion. They were in the stone access tunnel (drift), a distance from the pit bottom area where the main workplaces were located. Although initially overcome, Daniel Rockhouse rescued himself and his colleague Russell Smith.

The New Zealand Police led the emergency response that involved emergency services, and mines rescue crews from New Zealand, New South Wales and Queensland. Despite strenuous efforts by everyone involved, a lack of information concerning the conditions underground prevented a rescue attempt.

A second explosion on Wednesday 24 November extinguished any hope of the mens survival. The emergency focus changed to recovery of the bodies.

Image Credit: AFP

On November 22, 2016, an isobutane release and fire seriously injured four workers in the sulfuric acid alkylation unit at the ExxonMobil Refinery in Baton Rouge, Louisiana (‘Baton Rouge refinery’). During removal of an inoperable gearbox on a plug valve, the operator performing this activity removed critical bolts securing the pressure-retaining component of the valve known as the top-cap. When the operator then attempted to open the plug valve with a pipe wrench, the valve came apart and released isobutane into the unit, forming a flammable vapor cloud. The isobutane reached an ignition source within 30 seconds of the release, causing a fire and severely burning four workers who were unable to exit the vapor cloud before it ignited.

KEY ISSUES:
• HUMAN FACTORS
• EQUIPMENT DESIGN
• HIERARCHY OF CONTROLS
• OPERATING PROCEDURES & TRAINING

ROOT CAUSES:
1. Human factors associated with operational difficulties that exist in machinery and other equipment.
2. Deficient procedures for workers performing potentially hazardous work.
3. Inadequate training to ensure workers can perform all anticipated job tasks safely.

Image credit: CSB

On Sunday, November 29, 2015, an operator at the Delaware City Refining Company’s (DCRC) sulfuric acid alkylation unit suffered second-degree burns to the face and neck and third-degree burns to the wrist from a flash fire. The incident occurred when operations personnel were preparing equipment for maintenance work by de-inventorying and draining vessels located between two isolation points. A single block valve isolated the vessels being decontaminated from a pressurized and inventoried depropanizer column containing hydrocarbons; unknown to operations personnel, the valve leaked in the closed position, resulting in backflow of flammable material from the depropanizer. When an operator opened the vessel drain valve to empty what he assumed was condensate water from the vessel to the oil water sewer, the hydrocarbons from the depropanizer also released to the sewer and ignited, resulting in a flash fire.

Prior to maintenance work, operations personnel commonly prepare equipment by depressurizing, de-inventorying, washing, and draining. These activities often involve opening process equipment and piping and can result in a release of hazardous energy. Though equipment preparation activities can occur rather frequently in process plants, the tasks involved may vary among pieces of equipment and piping and combinations of equipment and, thus, may be non-routine and not be included in an existing procedure. Because of the non-routine nature of equipment preparation activities, process plants should develop a system to ensure that equipment preparation activities are carefully planned, which includes selecting proper isolation methods and identifying hazards through a risk assessment.

KEY ISSUES:
• OPERATING PROCEDURES
• MAINTENANCE PROCEDURES
• EQUIPMENT ISOLATION
• MANAGEMENT OF CHANGE
• DRAINING EQUIPMENT TO SAFE LOCATION

ROOT CAUSES:
1. Deficiencies in planning & executing non-routine equipment preparation activities

Image credit: CSB

An explosion and fire that occurred in a polyethylene wax processing facility operated by Marcus Oil and Chemical on the southwest side of Houston, Texas. On Friday, December 3, 2004, at about 5:50 pm, employees heard a loud “pop” then saw light from a fire reflecting off a shiny tanker truck parked near the process equipment. About 45 seconds later, a violent explosion occurred and a fire fueled by molten wax erupted near the main warehouse. The warehouse and nearby equipment were quickly involved in the fire.

The Houston Fire Department arrived approximately five minutes after the explosion. Firefighters extinguished the three-alarm blaze by midnight, approximately seven hours after the explosion.

Three firefighters were slightly injured while fighting the fire, and local residents sustained minor injuries from flying glass. The explosion shattered windows in buildings and vehicles and caused structural damage as far as one-quarter mile away. Significant interior damage resulted when suspended ceilings and light fixtures were blown down in the onsite buildings, nearby businesses, and a church. Tank 7, a 12-foot diameter, 50-foot long, 50,000-pound pressure vessel was propelled 150 feet where it impacted a warehouse belonging to another business..

KEY ISSUES:
• PRESSURE VESSEL REPAIRS & ALTERATIONS
• NITROGEN INERTING SYSTEM DESIGN & OPERATION

ROOT CAUSES:
1. Poor welding severely weakened Tank 7 and led to its catastrophic failure.
2. The connection between the nitrogen and the compressed air systems increased the oxygen concentration in the inerting gas to an unsafe level.
3. Pressure vessels had operating pressures in excess of 100 psig, yet none was equipped with a pressure relief device.

Image Credit: CSB

On December 7, 2009, at approximately 2:30 pm, State Special Vessel No. 2, under an operating pressure of 29,000 psig, suddenly and violently ruptured, 120 days into a 150-day operating cycle. A white cloud of steam and debris rapidly expanded outward from the facility, traveled onto the interstate, and dissipated within seconds.

The sudden release of superheated liquid caused an eight-foot tall by four-foot wide vessel fragment, weighing approximately 8,600 pounds, to travel through two concrete walls and finally land about 435 feet from the NDK building. The fragment skipped across a neighboring facility parking lot and slammed into the wall of an adjacent business office. The force of the impact pushed the wall inward causing furniture to shift and ceiling tiles to fall. One person working near the wall was injured.

The thrust from the escaping liquid caused the base of the vessel to violently shear away from its foundation and blew pieces of structural steel out of the building into the parking lot of a nearby rest stop gas station, known as the Illinois Tollway (I-90) Oasis. One piece of structural steel struck and killed a truck driver at the rest stop. After shearing from its base and throwing shrapnel out of the facility, the vessel swung from the building and landed on the ground outside.

KEY ISSUES:
• PRESSURE VESSEL DESIGN & MATERIAL SELECTION REQUIREMENTS
• LEARNING FROM PREVIOUS INCIDENTS
• INSPECTIONS

ROOT CAUSES:
1. Stress corrosion cracking.
2. Testing & inspection deficiencies.

Image credit: CSB

A release of hexane created a vapor cloud which was ignited on an electric motor, causing an explosion. This resulted in damage to a process unit and injured 20 people. The plant was eventually replaced.

[ Property Damage $200 Million. Estimated Current Value $280 Million ]

Image credit: Gaulke

A straight run of eight-inch-diameter line carrying hot oil from the high pressure separator to the low pressure stripper in a refinery hydrodesulfurizer fractured circumferentially in the parent metal in the heat zone about 1.5 inches from a weld. Hot oil at 700 psi and 650°F sprayed across the roadway into the hydrogen units where ignition occurred. An intense fire around the pipe rack in the hydrogen plant caused a 16-inch-diameter gas line to rupture, adding a second blow torch to the fire. More pipes ruptured with explosive force in adjacent areas. The fire resulted in a crash shutdown of the entire 600,000 bbl/d refinery. After six and a half hours, the fire was extinguished. Damage was extensive. The three hydrogen plants and the four hydrodesulphurization (HDS) units were heavily damaged or destroyed. Before the loss, the line which failed was judged as having excessive vibration. It is believed that the hot oil line failed due to fatigue, considered, in turn, to be largely due to hydrogen embrittlement.

[ Property Damage $75 Million. Estimated Current Value $180 Million ]

Image credit: PDVSA

This incident occurred at an oil sands facility, specifically with minor explosions occurring in the froth treatment plant. Damage appeared to be mainly limited to electrical cables in the solvent recovery area. The cause of the fire appears to have been a hydrocarbon leak in piping. The plant’s emergency response team was assisted by the local fire brigade and the fire was extinguished in two hours. Only one minor injury was reported. The incident occurred eight days after the new facility began operating.

[ Property Damage $120 Million. Estimated Current Value $189 Million ]

Image credit: Jason Woodhead

On January 9, 2014, West Virginia Department of Environmental Protection (WVDEP) inspectors arrived at the Freedom Industries (Freedom) chemical storage and distribution facility in Charleston, West Virginia, in response to complaints from the public about a chemical odor. Upon arrival, WVDEP inspectors discovered a chemical leaking from tank 396, an aboveground storage tank (AST). The leaking tank contents were originally reported as crude methylcychohexanemethanol (MCHM), but 13 days later Freedom reported it was a mixture of Crude MCHM and polyglycol ethers (PPH, stripped) called Shurflot 944.5 The chemical mixture escaped tank 396 through two small holes on the tank floor and traveled down a descending bank into the adjacent Elk River. The holes were caused by pitting corrosion that initiated on the internal surface of the tank floor. The tank contents drained into the gravel and soil surrounding tank 396 and found multiple pathways into the river. The secondary containment or dike wall, originally designed to control leaks, had cracks and holes from disrepair that allowed the mixture, containing Crude MCHM and PPH, stripped, to escape the containment. The leak also found a pathway to the river through a subsurface culvert, located under adjacent ASTs.

After prompting by WVDEP, Freedom took action to stop the leak and prevent further contamination by deploying services to recover the spill and vacuum the remaining tank contents. However, nearly 11,000 gallons of a mixture containing Crude MCHM and PPH, stripped had already entered into the surrounding soil and Elk River. Once in the river, it flowed downstream to the intake of the West Virginia American Water (WVAW) water treatment facility, about 1.5 miles downriver from Freedom. WVAW’s water treatment and filtration methods were unable to treat and remove all of the chemical mixture in its water treatment process and as a result, it contaminated the drinking water within WVAW’s distribution system. That evening, WVAW issued a Do Not Use (DNU) order for 93,000 customer accounts (approximately 300,000 residents) across portions of nine counties.

KEY ISSUES:
• TANK INSPECTIONS & MAINTENANCE
• RISK COMMUNICATION
• PUBLIC WATER SYSTEMS SAFETY & RISK ASSESSMENT
• TOXICOLOGICAL INFORMATION

ROOT CAUSES:
1. Corrosion of primary containment
2. Deteriorated secondary containment

Image credit: CSB

On Wednesday, January 11, 2006, three workers continued the roof removal. About 11:15 a.m., the lead mechanic and the third worker were cutting the metal roof directly above the methanol tank vent. Sparks, showering down from the cutting torch, ignited methanol vapors coming from the vent, creating a fireball on top of the tank. The fire flashed through a flame arrester on the vent, igniting methanol vapors and air inside the tank, causing a explosion inside the steel tank.

The explosion inside the methanol storage tank
• rounded the tank’s flat bottom, permanently deforming the tank and raising the side wall about onefoot;
• ripped the nuts from six bolts used to anchor the tank to a concrete foundation;
• blew the flame arrester off the tank vent pipe;
• blew a level sensor off a 4-inch flange on the tank top;
• separated two 1-inch pipes, valves, and an attached level switch from flanges on the side of the tank;
• separated a 4-inch tank outlet pipe from the tank outlet valve; and
• separated a 4-inch tank fill pipe near the top the tank.

Methanol discharged from the separated pipes ignited and burned, spreading the fire. Methanol also flowed into the containment around the tank and through a drain to the WWTP where it was diluted and harmlessly processed. The lead mechanic and the third worker were in the man-lift basket over the methanol tank when the ignition occurred. They were likely burned from the initial fireball and burning methanol vapors discharging from the tank vent under pressure from the explosion. The lead mechanic, fully engulfed in fire, likely jumped or fell from the man-lift. Emergency responders found his body within the concrete containment next to the tank.

The third worker stated that he had been partially out of the man-lift basket leaning over the roof when the fire ignited. On fire, he climbed onto the roof to escape. Co-workers, unable to reach him with a ladder, told him to jump to an adjacent lower roof and then to the ground. He sustained second and third degree burns over most of his body, and was hospitalized for 4 months before being released to a medical rehabilitation facility. Methanol sprayed from separated pipes onto the crane, burning the crane cab with the mechanic inside. On fire, he exited the cab and was assisted by co-workers. He died in the hospital the following day.

KEY ISSUES:
• HAZARD COMMUNICATION
• HOT WORK CONTROL
• PLASTIC PIPE IN FLAMMABLE SERVICE
• FLAME ARRESTER MAINTENANCE
• FLORIDA PUBLIC EMPLOYEE SAFETY PROGRAMS

ROOT CAUSES:
1. The City of Daytona Beach did not implement adequate controls for hot work at the Bethune Point WWTP.
2. The City of Daytona Beach had a hazard communication program that did not effectively communicate the hazards associated with methanol at the Bethune Point WWTP.

Image credit: CSB

A release of hot light hydrocarbon during the completion of a maintenance activity resulted in a major fire. The fire occurred on a residual fluid catalytic cracking (RFCC) unit that had recently been commissioned as part of a major expansion, doubling the overall refinery capacity. The fire resulted in the closure of the expanded area of the refinery while extensive rebuilding activity was delivered. The value of the property damage loss is currently estimated to be in excess of US$1 billion.

[ Property Damage $1000 Million. Estimated Current Value $1000 Million ]

Image credit: ADNOC

On the evening of January 12, 2009, 2 refinery operators and 2 contractors suffered serious burns resulting from a flash fire at the Silver Eagle Refinery in Woods Cross, Utah. The accident occurred when a large flammable vapor cloud was released from an atmospheric storage tank, known as tank 105, which contained an estimated 440,000 gallons of light naphtha. The vapor cloud found an ignition source and the ensuing flash fire spread up to 230 feet west of the tank farm.

On November 4, 2009, a second accident occurred at the Silver Eagle Refinery in Woods Cross, Utah, when a powerful blast wave – caused by the failure of a 10 inch pipe – damaged nearby homes.

KEY ISSUES:
• MECHANICAL INTEGRITY

ROOT CAUSES:
1. Sulfidation corrosion

Image credit: CSB

On 17 January 1981 at approximately 00:07 hours operators on the plant observed an explosion followed by a fire. They immediately evacuated the area. On-site security initiated the on-site emergency procedures and called both the works fire brigade and the local authority fire brigade. Staff in a nearby control room initiated shut down procedures.

On arrival at the site the fire service set up two cooling sprays onto LPG pipelines within the plant. The deployment of additional water sprays was advised to protect unaffected pipelines (carrying kerosene, white spirit, petrol, fuel gas, high pressure steam, low pressure steam and lubricating oil) from the heat of the burning propane.

Residual propane in the plant was permitted to burn off and the severity of the fire gradually diminished. By 07:58 hours the fire was under control. Isolated pockets of oil residues continued to burn for some hours later.

Propane gas, contained in two 20 tonne storage vessels, was consumed by fire, and the area around the vessels was severely damaged.

The incident investigation believed that the release of gas occurred as the result of a damaged seal on a propane recirculating pump. Fire damage of control cables made process isolation difficult.

Fire severely damaged the de-asphalting plant and pipe work, the supporting structures and the feedstock storage tanks

KEY ISSUES:
• INSPECTION / NON-DESTRUCTIVE TESTING (NDT)
• ACTIVE / PASSIVE FIRE PROTECTION

Image Credit: Ben Brooksbank

An explosion occurred at one of Petrobras’ refineries. The blast occurred at a hydrogen conduit in an enclosed space, causing a flare and a displacement of air that threw the contract workers against the refinery’s metal structure.

Proximate causes:
• Inadequate maintenance
• Failure following procedures
• Lack of work rules/policies/ standards/procedures
• Physical condition (the accident may have been the result of maintenance work being carried out under tight deadlines and long shifts imposed on refinery workers)
• Mental stress
• Mental state

Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)
Image Credit: Daily Motion

An explosion at a liquefied natural gas (LNG) plant resulted in 27 people killed, 72 injured, and seven reported missing. The explosion destroyed three out of six liquefaction trains, damaged a nearby power plant, and led to the shutdown of a 335,000 bbl per day refinery. There was also some damage to the neighboring industrial facilities. A faulty boiler was initially blamed for the incident. Investigations, however, indicated that a large release of hydrocarbon from a cold-box exchanger was ignited upon ingestion into the boiler. Train six of the LNG complex re-started in May 2004 and trains five and 10 in September 2004. Trains 20, 30, and 40 were destroyed in the incident, representing 50% of the capacity of the LNG complex.

[ Property Damage $470 Million. Estimated Current Value $689 Million ]

Image credit: Sonatrach

On January 22 and 23, 2010, three separate incidents at the DuPont plant in Belle, WV, involving releases of methyl chloride, oleum, and phosgene, triggered notification of outside emergency response agencies. The incident involving the release of phosgene gas led to the fatal exposure of a worker performing routine duties in an area where phosgene cylinders were stored and used.

Operators discovered the first incident, the release of methyl chloride, the morning of January 22, 2010, when an alarm sounded on the plant’s distributed control system monitor. They confirmed that a release had occurred and that methyl chloride was venting to the atmosphere. Managers assessing the release estimated that more than 2,000 pounds of methyl chloride may have been released over the preceding 5 days.

The oleum release, the second incident, occurred the morning of January 23, 2010. Workers discovered a leak in an overhead oleum sample pipe that was allowing a fuming cloud of oleum to escape to the atmosphere. The plant fire brigade, after donning the appropriate personal protective equipment, closed a valve that stopped the leak about an hour after it was discovered. No injuries occurred, but the plant called the Belle Volunteer Fire Department to assist.

The third incident, a phosgene release, occurred later that same day when a hose used to transfer phosgene from a 1-ton cylinder to a process catastrophically failed and sprayed a worker in the face while he was checking the weight of the cylinder. The employee, who was alone when exposed, was assisted by co-workers who immediately responded to his call for help. Initial assessments by the plant’s occupational health nurse indicated that the worker showed no symptoms of exposure prior to transport to the hospital for observation and treatment. A delayed onset of symptoms, consistent with information in phosgene exposure literature, occurred after he arrived at the hospital. His condition deteriorated over the next day and he died from his exposure the next night.

KEY ISSUES:
• MECHANICAL INTEGRITY
• ALARM MANAGEMENT
• OPERATING PROCEDURES
• COMPANY EMERGENCY RESPONSE & NOTIFICATION

ROOT CAUSES:

Methyl Chloride Incident (January 22, 2010)
1. DuPont management, following their Management of Change process, approved a design for the rupture disc alarm system that lacked sufficient reliability to advise operators of a flammable methyl chloride release.

Oleum Release Incident (January 23, 2010)
1. Corrosion under the insulation caused a small leak in the oleum pipe.

Phosgene Incident (January 23, 2010)
1. DuPont’s phosgene hazard awareness program was deficient in ensuring that operating personnel were aware of the hazards associated with trapped liquid phosgene in transfer hoses.
2. DuPont relied on a maintenance software program that was subject to changes without authorization or review, did not automatically initiate a change-out of phosgene hoses at the prescribed interval, and did not provide a back-up process to ensure timely change-out of hoses.
3. DuPont Belle’s near-miss reporting process was not rigorous enough to ensure that the near failure of a similar phosgene transfer hose, just hours prior to the exposure incident, would be immediately brought to the attention of plant supervisors and managers.
4. DuPont lacked a dedicated radio/telephone system and emergency notification process to convey the nature of an emergency at the Belle plant, thereby restricting the ability of personnel to provide timely and quality information to emergency responders.

Image credit: CSB

The Space Shuttle Challenger disaster was a fatal incident in the United States space program that occurred on Tuesday, January 28, 1986, when the Space Shuttle Challenger (OV-099) broke apart 73 seconds into its flight, killing all seven crew members aboard. The crew consisted of five NASA astronauts, one payload specialist, and a civilian schoolteacher. The mission carried the designation STS-51-L and was the tenth flight for the Challenger orbiter.

The spacecraft disintegrated over the Atlantic Ocean, off the coast of Cape Canaveral, Florida, at 11:39 a.m. EST (16:39 UTC). The disintegration of the vehicle began after a joint in its right solid rocket booster (SRB) failed at liftoff. The failure was caused by the failure of O-ring seals used in the joint that were not designed to handle the unusually cold conditions that existed at this launch. The seals’ failure caused a breach in the SRB joint, allowing pressurized burning gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB aft field joint attachment hardware and external fuel tank. This led to the separation of the right-hand SRB’s aft field joint attachment and the structural failure of the external tank. Aerodynamic forces broke up the orbiter.

Image Credit: NASA

On January 30, 2007, a propane explosion at the Little General Store in Ghent, West Virginia, killed two emergency responders and two propane service technicians, and injured six others. The explosion leveled the store, destroyed a responding ambulance, and damaged other nearby vehicles.

On the day of the incident, a junior propane service technician employed by Appalachian Heating was preparing to transfer liquid propane from an existing tank, owned by Ferrellgas, to a newly installed replacement tank. The existing tank was installed in 1994 directly next to the store’s exterior back wall in violation of West Virginia and U.S. Occupational Safety and Health Administration regulations.

When the technician removed a plug from the existing tank’s liquid withdrawal valve, liquid propane unexpectedly released. For guidance, he called his supervisor, a lead technician, who was offsite delivering propane. During this time propane continued releasing, forming a vapor cloud behind the store. The tank’s placement next to the exterior wall and beneath the open roof overhang provided a direct path for the propane to enter the store.

About 15 minutes after the release began, the junior technician called 911. A captain from the Ghent Volunteer Fire Department subsequently arrived and ordered the business to close. Little General employees closed the store but remained inside. Additional emergency responders and the lead technician also arrived at the scene. Witnesses reported seeing two responders and the two technicians in the area of the tank, likely inside the propane vapor cloud, minutes before the explosion.

Minutes after the emergency responders and lead technician arrived, the propane inside the building ignited. The resulting explosion killed the propane service technicians and two emergency responders who were near the tank. The blast also injured four store employees inside the building as well as two other emergency responders outside the store.

KEY ISSUES:
• EMERGENCY EVACUATION
• HAZARDOUS MATERIALS INCIDENT TRAINING FOR FIREFIGHTERS
• 911 CALL CENTER RESOURCES
• PROPANE COMPANY PROCEDURES
• PROPANE SERVICE TECHNICIAN TRAINING

ROOT CAUSES:
1. The Ferrellgas inspection and audit program did not identify the tank location as a hazard. Consequently, the tank remained against the building for more than 10 years.
2. Appalachian Heating did not formally train the junior technician, and on the day of incident he was working alone.
3. Emergency responders were not trained to recognize the need for immediate evacuation during liquid propane releases.

Image credit: CSB

Four people were killed in an explosion and fire at an oil gathering center, gas booster station, and power substation. The explosion occurred after a leak from a buried oil pipeline in the gathering station spread to a power substation, sparking the blaze. The flash explosion and resulting blaze hit the gathering center and the adjacent gas booster station. At least 19 people were injured in the incident, mainly suffering first- and second-degree burns. The fire was extinguished two days after the event.

[ Property Damage $150 Million. Estimated Current Value $246 Million ]

Image credit: BBC

A gas leak followed by explosion occurred during an inspection process due to the loose of valve bolt.

Proximate causes:
• Inadequate training/knowledge transfer (Lack of understanding the process);
• Lack of work rules/policies/ standards/procedures (wrong procedures for inspections);
• Inadequate work rules plan (lack of the pre-start safety review before inspection).

Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)
Image Credit: Wikipedia