Contributory Factors: ORGANIZATIONAL

On February 7, 2008, at about 7:15 p.m., a series of sugar dust explosions at the Imperial Sugar manufacturing facility in Port Wentworth, Georgia, resulted in 14 worker fatalities. Eight workers died at the scene and six others eventually succumbed to their injuries at the Joseph M. Still Burn Center in Augusta, Georgia. Thirty six workers were treated for serious burns and injuries – some caused permanent, life altering conditions. The explosions and subsequent fires destroyed the sugar packing buildings, palletizer room, and silos, and severely damaged the bulk train car loading area and parts of the sugar refining process areas.

KEY ISSUES:
• COMBUSTIBLE DUST HAZARD RECOGNITION
• MINIMIZING COMBUSTIBLE DUST ACCUMULATION IN THE WORKPLACE
• EQUIPMENT DESIGN & MAINTENANCE

ROOT CAUSES:
1. Sugar and cornstarch conveying equipment was not designed or maintained to minimize the release of sugar and sugar dust into the work area.
2. Inadequate housekeeping practices resulted in significant accumulations of combustible sugar and sugar dust on the floors and elevated surfaces throughout the packing buildings.
3. Imperial Sugar emergency evacuation plans were inadequate. Emergency evacuation drills were not conducted, and prompt worker notification to evacuate in the event of an emergency was inadequate.

Image credit: CSB

A February 7, 2003, explosion and fire inside a vent collection system (VCS) at Technic Inc., in Cranston, Rhode Island, critically injured one employee, who suffered permanent eye damage and chemical burns to his face and upper body. Eighteen other employees were sent to the hospital for medical evaluations, and the fire department evacuated the surrounding community. Facility operations were interrupted for several weeks.

The explosion and fire were caused by a violent chemical reaction inside the vent collection system, which was likely initiated when the employee tapped on a duct with a small hammer. The building where the incident occurred housed several chemical processes that were connected to the ventilation system.

KEY ISSUES:
• INCOMPATIBLE CHEMICAL MIXING
• PROCESS SAFETY REVIEW
• MANAGEMENT OF CHANGE
• PREVENTIVE MAINTENANCE
• EMERGENCY PLANNING & RESPONSE

ROOT CAUSES:
1. Technic did not conduct a process safety review as a part of the engineering process to identify and evaluate the hazards associated with installing a vent collection system to handle the exhausts from multiple processes.
2. Technic did not identify and evaluate the hazards created by changes to facility processes and equipment (i.e., management of change).

Image Credit: CSB

Six workers were fatally injured during a planned work activity to clean debris from natural gas pipes at Kleen Energy in Middletown, CT. To remove the debris, workers used natural gas at a high pressure of approximately 650 pounds per square inch. The high velocity of the natural gas flow was intended to remove any debris in the new piping. During this process, the natural gas found an ignition source and exploded.

KEY ISSUES:
• SIMILAR NATURAL GAS BLOW INCIDENTS
• INDUSTRY PRACTICES AND SAFER ALTERNATIVE METHODOLOGIES
• HAZARDS OF RELEASING NATURAL GAS NEAR WORK AREAS
• CODES AND STANDARDS

ROOT CAUSES:
1. Natural gas blows are common
2. Workers remained in building during gas blow

Image credit: CSB

An explosion occurred when 8 personnel were working on the repair of a catalyst tower.

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)

On Wednesday, February 8, 2017, at approximately 11:05 am, a foul condensate tank, part of a non-condensable gas system, exploded at the Packaging Corporation of America (PCA) containerboard mill in DeRidder, Louisiana. The explosion killed three people and injured seven others. All 10 people were working at the mill as contractors. The explosion also heavily damaged the surrounding process. The foul condensate tank travelled approximately 375 feet and over a six-story building before landing on process equipment.

At the time of the incident, the mill was undergoing its annual planned maintenance outage, also referred to as a shutdown. The foul condensate tank likely contained water, a layer of flammable liquid turpentine on top of the water, and an explosive vapor space containing air and flammable turpentine vapor.

KEY ISSUES:
• PROCESS SAFETY MANAGEMENT SYSTEM
• INHERENTLY SAFER DESIGN
• PROCESS HAZARD ANALYSIS
• INEFFECTIVE SAFEGUARDS
• HOT WORK SAFETY MANAGEMENT

ROOT CAUSES:
1. PCA did not evaluate the majority of the non-condensable gas system, including the foul condensate tank, for certain hazards. The DeRidder mill never conducted a process hazard analysis to identify, evaluate, and control process hazards for the non-condensable gas system.
2. PCA did not expand the boundaries of its process safety management program beyond the units covered by safety regulations.
3. PCA did not effectively apply the hierarchy of controls to the selection and implementation of safeguards that the company used to prevent a potential non-condensable gas explosion.
4. PCA did not evaluate inherently safer design options that could have eliminated the possibility of air entering the non-condensable gas system, including the foul condensate tank.
5. PCA did not establish which mill operations group held ownership of, and responsibility for, the foul condensate tank.
6. PCA did not apply important aspects of industry safety guidance and standards.

Image credit: CSB

On February 12, 2014, a mechanical integrity failure released sulfuric acid in the alkylation unit, which burned two Tesoro Martinez refinery employees. Approximately 84,000 pounds of sulfuric acid were released during the incident.

On March 10, 2014, sulfuric acid sprayed and burned two contract workers while they removed piping in the same alkylation unit. The CSB found that this second incident shared similar causation with a 1999 incident at the same refinery, then called the Avon refinery, owned by the Tosco Corporation, that resulted in four fatalities. Similarities between the two incidents suggest that the Tesoro Martinez refinery did not effectively continue to implement or communicate important safety lessons from the 1999 Tosco incident.

KEY ISSUES:
• PROCESS SAFETY CULTURE
• PROCESS SAFETY INDICATORS

ROOT CAUSES:
1. The safety culture at the Tesoro Martinez refinery created conditions conducive to the occurrence and recurrence of process safety incidents that caused worker injuries at the refinery over several years.
2. Prior sulfuric acid exposure incidents at the Tesoro Martinez refinery could have properly been considered leading indicators of an impending serious chemical accident and then triggered preventive inspections and review of the refinery’s safety systems and equipment.

Image & AcciMap Credit: CSB

Image credit: CSB

Explosion in an oil and gas production ship rented by Petrobras. The explosion occurred aboard the FPSO unit. A leak of flammable substance in the pump room was the cause of the explosion.

Proximate causes:
• Failure in following procedures
• Lack of work rules/policies/ standards/procedures (breach of operational procedures for the pumping of fluids)
• Inadequate engineering/design
• Inadequate management/ supervision (installation of equipment in pipe without proper technical specification and registration of the change)
• Work exposure to hazardous chemicals (flammable substances) Inadequate assessment of needs and risks

Marsh (https://www.marsh.com/us/insights/research/100-largest-losses-in-the-hydrocarbon-industry.html):

An explosion on a FPSO off the coast of Brazil resulted in nine fatalities and multiple wounded. The accident happened as the vessel was anchored in the Atlantic Ocean 120 kilometres from the coast of Espirito Santos, Brazil. The FPSO is a converted very large crude oil tanker (VLCC), designed to produce up to 10 million cubic meters of natural gas. It is understood that a condensate leak during a fluid transfer operation released a cloud of flammable vapor into the engine room, resulting in an explosion in the machinery space. The majority of fatalities were believed to be part of the emergency response team. FPSO took on water, but the explosion did not result in a breach of the hull of the vessel.

[ Property Damage $250 Million. Estimated Current Value $264 Million ]

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

A rail car with more than 100 tanks of crude bakken oil derailed in West Virginia, generating a huge fireball, the evacuation of hundreds of people and, a spill into the Kanawha River.

Hundreds evacuated – FRE issued CSX and Sperry Rail Service $25.000 fines each

Proximate causes:
• Inadequate tools, equipment & vehicles (rail defect)

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

On Wednesday, February 18, 2015, an explosion occurred in the ExxonMobil Torrance, California refinery’s Electrostatic Precipitator (ESP), a pollution control device in the fluid catalytic cracking (FCC) unit that removes catalyst particles using charged plates that produce sparks (potential ignition sources) during normal operation. The incident occurred when ExxonMobil was attempting to isolate equipment for maintenance while the unit was in an idled mode of operation; preparations for the maintenance activity caused a pressure deviation that allowed hydrocarbons to backflow through the process and ignite in the ESP.

The CSB found that this incident occurred due to weaknesses in the ExxonMobil Torrance refinery’s process safety management system. These weaknesses led to operation of the FCC unit without pre-established safe operating limits and criteria for unit shutdown, reliance on safeguards that could not be verified, the degradation of a safety-critical safeguard, and the re-use of a previous procedure deviation without a sufficient hazard analysis that confirmed that the assumed process conditions were still valid. .

KEY ISSUES:
• LACK OF SAFE OPERATING LIMITS & OPERATING PROCEDURE
• SAFEGUARD EFFECTIVENESS
• OPERATING EQUIPMENT BEYOND SAFE OPERATING LIFE
• RE-USE OF PREVIOUS PROCEDURE VARIANCE WITHOUT SUFFICIENT HAZARD ANALYSIS

ROOT CAUSES:
1. ExxonMobil did not establish the safe operating limits for operating the FCC unit in Safe Park (a standby mode of operation) or determine process conditions that required unit shutdown.
2. ExxonMobil did not perform a sufficient hazard analysis to determine if the unit conditions specified in the 2012 procedure were valid for the 2015 operation.
3. ExxonMobil operated FCC unit equipment beyond its predicted safe operating life.
4. ExxonMobil lacked safety instrumentation to detect flammable hydrocarbons flowing through the equipment and into the ESP.
5. ExxonMobil refinery management permitted opening process equipment without conforming to refinery standards.

Image credit: CSB

An explosion occurred due to an overflow of a slurry mixing tank, containing potassium sulfide, potassium dihydrogen phosphate, and MAP.

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)

A February 20, 2003, dust explosion at the CTA Acoustics, Inc. (CTA) facility in Corbin, Kentucky, killed seven and injured 37 workers. This incident caused extensive damage to the production area of the 302,000-square-foot plant. Nearby homes and an elementary school were evacuated, and a 12-mile section of Interstate 75 was closed. The largest CTA customer, Ford Motor Company, temporarily suspended operations at four automobile assembly plants because CTA had produced acoustic insulation products for those plants, as well as for other industrial and automotive clients.

KEY ISSUES:
• COMBUSTIBLE DUST HAZARD AWARENESS
• WORK PRACTICES
• BUILDING DESIGN
• PRODUCT STEWARDSHIP

ROOT CAUSES:
1. CTA management did not implement effective measures to prevent combustible dust explosions.
2. The CTA cleaning and maintenance procedures for production lines did not prevent the accumulation of unsafe levels of combustible dust on elevated flat surfaces.
3. The CTA incident investigation program did not ensure that all oven fires were investigated and that underlying causes were identified and resolved.
4. The Borden Chemical product stewardship program did not explicitly convey to CTA the explosive hazards of phenolic resins.
5. The original building design and subsequent building modifications did not effectively address the fire and explosion hazards associated with combustible dusts.

Image Credit: CSB

On February 23, 1999, a fire occurred in the crude unit at Tosco Corporation. Avon oil refinery in Martinez, California. Workers were attempting to replace piping attached to a 150-foot-tall fractionator tower while the process unit was in operation. During removal of the piping, naphtha was released onto the hot fractionator and ignited. The flames engulfed five workers located at different heights on the tower. Four men were killed, and one sustained serious injuries.

KEY ISSUES:
• CONTROL OF HAZARDOUS NONROUTINE MAINTENANCE
• MANAGEMENT OVERSIGHT & ACCOUNTABILITY
• MANAGEMENT OF CHANGE
• CORROSION CONTROL

ROOT CAUSES:
1. Tosco Avon refinery’s maintenance management system did not recognize or control serious hazards posed by performing nonroutine repair work while the crude processing unit remained in operation.
2. Tosco’s safety management oversight system did not detect or correct serious deficiencies in the execution of maintenance and review of process changes at its Avon refinery.

Image Credit: CSB

A high-pressure steam (3.7 MPa) discharge occurred during a maintenance process, resulting in three field workers burned to death.

Proximate causes:
• 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)

Four reactors exploded after an initial fire in a warehouse in the plant. The toxic gas released due to the fire and explosion affected the local community. Electrical short circuit and improper shutdown was the reason that triggered the incident.

Proximate causes:
• Inadequate tools, equipment & vehicles (Electrical appliances shortcut)
• Failure in following procedure (improper shutdown)

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

On March 13, 2001, three people were killed as they opened a process vessel containing hot plastic at the BP Amoco Polymers plant in Augusta, Georgia. They were unaware that the vessel was pressurized. The workers were killed when the partially unbolted cover blew off the vessel, expelling hot plastic. The force of the release caused some nearby tubing to break. Hot fluid from the tubing ignited, resulting in a fire.

KEY ISSUES:
• RECOGNITION OF REACTIVE HAZARDS
• LEARNING FROM NEAR-MISS INCIDENTS
• OPENING OF PROCESS EQUIPMENT

ROOT CAUSES:
1. Amoco, the developer of the Amodel process, did not adequately review the conceptual process design to identify chemical reaction hazards.
2. The Augusta facility did not have an adequate review process for correcting design deficiencies.
3. The Augusta site system for investigating incidents and nearmiss incidents did not adequately identify causes or related hazards. This information was needed to correct the design and operating deficiencies that led to the recurrence of incidents.

Image Credit: CSB

An explosion occurred when 6 personnel were working on the repair of a catalyst tower

Proximate causes:
• 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)

At approximately 1:20 p.m. on March 23, 2005, a series of explosions occurred at the BP Texas City refinery during the restarting of a hydrocarbon isomerization unit. Fifteen workers were killed and 180 others were injured. Many of the victims were in or around work trailers located near an atmospheric vent stack. The explosions occurred when a distillation tower flooded with hydrocarbons and was overpressurized, causing a geyser-like release from the vent stack.

KEY ISSUES:
• SAFETY CULTURE
• REGULATORY OVERSIGHT
• PROCESS SAFETY METRICS
• HUMAN FACTORS

ROOT CAUSES:
1. BP Group Board did not provide effective oversight of the company’s safety culture and major accident prevention programs.

2. Senior executives:
• inadequately addressed controlling major hazard risk. Personal safety was measured, rewarded, and the primary focus, but the same emphasis was not put on improving process safety performance;
• did not provide effective safety culture leadership and oversight to prevent catastrophic accidents;
• ineffectively ensured that the safety implications of major organizational, personnel, and policy changes were evaluated;
• did not provide adequate resources to prevent major accidents; budget cuts impaired process safety performance at the Texas City refinery.

3. BP Texas City Managers did not:
• create an effective reporting and learning culture; reporting bad news was not encouraged. Incidents were often ineffectively investigated and appropriate corrective actions not taken.
• ensure that supervisors and management modeled and enforced use of up-to-date plant policies and procedures.
• incorporate good practice design in the operation of the ISOM unit.
• ensure that operators were supervised and supported by experienced, technically trained personnel during unit startup, an especially hazardous phase of operation; or that
• effectively incorporated human factor considerations in its training, staffing, and work schedule for operations personnel.

Image Credit: CSB

On March 27, 1998, at approximately 12:15 pm, two workers at Union Carbide Corporation’s Taft/Star Manufacturing Plant (the plant) in Hahnville, Louisiana, were overcome by nitrogen gas while performing a black light inspection at an open end of a 48-inch-wide horizontal pipe. The 48-inch pipe was open because chemical-processing equipment had been shut down and opened for major maintenance. Nitrogen was being injected into the process equipment primarily to protect new catalyst in reactors from exposure to moisture. The nitrogen was also flowing through some of the piping systems connected to the reactors. The nitrogen was venting from one side of the open pipe where it had formerly been connected to an oxygen feed mixer. No warning sign was posted on the pipe opening identifying it as a confined space or warning that the pipe contained potentially hazardous nitrogen.

The two workers had placed a sheet of black plastic over the end of the pipe to provide shade to make it easier to conduct the black light test during daylight. While working just outside the pipe opening and inside of the black plastic sheet, the two workers were overcome by nitrogen. One worker died from asphyxiation. The other worker survived but was severely injured.

KEY ISSUES:
• USE OF NITROGEN IN CONFINED SPACES
• SAFETY OF TEMPORARY ENCLOSURES

ROOT CAUSES:
1. Procedures to control potential hazards created by erecting temporary enclosures around nitrogen-containing equipment were inadequate.
2. Nitrogen and confined space hazard warnings were inadequate.

Image Credit: CSB

A fire started inside a depot with 3 million liters of diesel and the flames spread to four neighboring storage tanks. The fire lasted for 9 days.

Fine of around USD $6.4 million (R$ 22.5 million). Environmental impact causing death of thousands of fish

Proximate causes:
• Inadequate management/ supervision
• Inadequate work planning

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

A blast occurred in a pumping station, after leaking oil caught fire. 177 fire engines and more than 800 firefighters were rushed to the blaze, and more than 14,000 residents in the surrounding area were evacuated.

Proximate causes:
• Improper use of protective methods (Improper welding of conveying pipe)

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

On April 8, 2004, four workers were seriously injured when highly flammable gasoline components were released and ignited at the Giant Industries Ciniza refinery, east of Gallup, New Mexico. The release occurred as maintenance workers were removing a malfunctioning pump from the refinery’s hydrofluoric acid (HF) alkylation unit. Unknown to personnel, a shut-off valve connecting the pump to a distillation column was apparently in the open position, leading to the release and subsequent explosions.

KEY ISSUES:
• MECHANICAL INTEGRITY
• CORROSION & SCALE FORMATION
• VALVE DESIGN
• HUMAN FACTORS CONSIDERATION
• MANAGEMENT OF CHANGE
• LOCKOUT/TAGOUT & ISOLATION

ROOT CAUSES:
1. An MOC hazard analysis was not conducted.
2. the facility lacked procedures to verify that the pump had been isolated, depressurized and drained.
3. Instead of determining the cause of frequent pump malfunctions and then implementing a program that would prevent problems before they occurred, Giant used breakdown maintenance by making repeated repairs to the pump seals after failure.

Image Credit: CSB

On April 8, 2011, at approximately 8:50 am, an explosion and fire occurred at a magazine known as ‘A-21’ located at Waikele Self Storage in Waipahu, Hawaii. Five Donaldson Enterprises, Inc. (DEI) employees were fatally injured and a sixth sustained minor injuries.

DEI, a small unexploded ordnance (UXO) clearance company based on the island of Oahu, was using the magazine to store seized contraband fireworks and prepare them for disposal. On the morning of the incident, five DEI personnel were disassembling one-inch contraband firework tubes on a cement loading dock located directly in front of the magazine entrance, while a sixth remained inside the magazine cleaning and organizing . To accomplish the disassembly work, DEI personnel cut into the individual firework tubes by hand using a PVC pipe cutter or knife and separated the individual explosive components contained within each tube, the aerial shells and the black powder (which functions as a lift charge) into cardboard boxes.

According to witness statements, around 8:30 am it began to rain heavily, and the DEI workers quickly moved materials involved in the disassembly process – including tools, chairs, and boxes containing aerial shells, black powder, and partially disassembled firework tubes – to just inside the magazine entrance. While five of the workers remained inside, the project supervisor went outside to the front left corner of the loading dock to make a phone call. While he was on the phone, an explosion occurred inside the magazine, and a fire ensued.

The five individuals located inside the magazine at the time of the incident did not survive. Three DEI employees sustained fatal burn injuries while two succumbed to carbon monoxide poisoning. The project supervisor sustained minor injuries.

KEY ISSUES:
• HAZARDS OF FIREWORKS DISPOSAL & THE ACCUMULATION OF EXPLOSIVE FIREWORKS COMPONENTS
• LACK OF REGULATIONS & INDUSTRY STANDARDS ADDRESSING FIREWORKS DISPOSAL
• INSUFFICIENT CONTRACTOR SELECTION & OVERSIGHT REQUIREMENTS FOR HAZARDOUS ACTIVITIES

ROOT CAUSES:
1. DEI’s hazard analysis of its fireworks disposal process was insufficient. The company failed to identify key hazards of handling, disassembling, and storing contraband commercial display fireworks, and did not adequately control the identified and evaluated hazards.
2. DEI personnel disposing of the fireworks lacked the training, experience, and knowledge of procedural safeguards for the safe conduct of the fireworks disposal.
3. DEI’s modifications to the fireworks disposal process accumulated substantially large quantities of explosive material in boxes, greatly increasing the potential explosion hazard. This change to the disposal process was not adequately reviewed for safety implications.

Image & AcciMap Credit: CSB

Image credit: CSB

On April 25, 2002, a chemical waste-mixing incident occurred at Kaltech Industries Group, Inc., a sign manufacturer located in the Chelsea district of New York City. At least 36 people were injured, including members of the public and six firefighters. Kaltech employees were consolidating hazardous waste from smaller containers into two larger drums when the explosion and fire occurred.

The Kaltech facility was located in a mixed-occupancy building in a densely populated urban area. Because the highly confined workspace in the basement offered limited pathways for the explosion to vent, there was extensive damage to the 10-story building. Street traffic was restricted for several days, and building tenants faced significant business interruptions.

KEY ISSUES:
• HAZARD COMMUNICATION
• HAZARDOUS WASTE HANDLING
• MUNICIPAL OVERSIGHT

ROOT CAUSES:
1. Kaltech did not develop or maintain a chemical hazard communication program in accordance with established OSHA standards.
2. Kaltech did not manage its hazardous waste in accordance with established EPA regulations.

Image Credit: CSB

On April 26, 2018, an explosion and subsequent fire occurred at the Superior Refinery Company LLC refinery in Superior, Wisconsin (‘Husky Superior Refinery’). The incident occurred in the refinery’s Fluid Catalytic Cracking Unit (FCCU). In preparation for the shutdown, the refinery brought in hundreds of contractors and increased operations staffing. The contractors were performing many tasks such as electrical work, preparing for chemical cleaning, building scaffolding, and welding. As a result of the explosion, thirty-six people sought medical attention, including eleven refinery and contract workers who suffered OSHA recordable injuries. In addition, a large portion of Superior, Wisconsin was evacuated. The refinery was shutting down in preparation for a five-week turnaround when an explosion occurred, sending several people to area hospitals with injuries.

KEY ISSUES:
• PYROPHORIC IRON SULFIDE

Image credit: CSB

In the early morning hours of May 1, 2002, a fire erupted at the Third Coast Industries Friendswood facility, located in an unincorporated area of Brazoria County, Texas. The facility (which blended and packaged motor oils, hydraulic oils, and engine and other lubricants) was inadequately designed and protected to prevent the spread of fire.

Firefighters arrived at the scene within minutes, but had insufficient means to fight the fire, which burned for more than 24 hours. The fire consumed 1.2 million gallons of combustible and flammable liquids and destroyed the site. One hundred nearby residents were evacuated, a local school was closed, and significant environmental cleanup was necessary due to fumes and runoff. No employees or firefighters were injured during the incident..

KEY ISSUES:
• FIRE CONTROL
• CONSENSUS STANDARDS
• FIRE CODES

ROOT CAUSES:
1. Third Coast did not conduct an adequate fire protection analysis to ensure implementation of fire protection measures.
2. The Third Coast facility fire suppression system was inadequate for detecting and warning of fire or smoke or for stopping fire spread.
3. The Third Coast facility lacked adequate control measures to limit the spread of the initial fire.

Image Credit: CSB

An electrical discharge in Acton Technologies company caused a fire in a warehouse were acetone was stored. School evacuation

Proximate causes:
• Hazardous work exposure

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

An explosion at Kuraray America on May 19, 2018, injured 21 workers at the EVAL facility in Pasadena, Texas. The facility manufactures ethylene vinyl-alcohol copolymers, sold as EVAL. Kuraray America is a Tokyo-based specialty chemical manufacturer.

During pre-startup pressure-testing activities of a chemical reactor, an abnormal high-pressure condition occurred and over 2,000 pounds of ethylene were released to the atmosphere from a pressure relief valve. The ethylene vapors ignited, resulting in worker injuries. Twenty-one injured workers were transported to off-site medical facilities for treatment.

KEY ISSUES:
• HOT WORK

Image credit: CSB

At approximately 11:00 PM on May 31, 2017, explosion(s) at the Didion Milling (Didion) facility in Cambria, Wisconsin, resulted in 5 worker deaths and an additional 14 workers injured. Because the event occurred at night, only 19 employees were working within the facility at the time of the incident.

Shortly before the explosion(s) at Didion, workers saw or smelled smoke on the first floor of one of the mill buildings. In trying to find its source, workers focused on a piece of equipment called a gap mill. While inspecting the equipment, workers witnessed a filter connected to an air intake line for the mill blow off, resulting in corn dust filling the air, and flames shooting from the air intake line, followed by one or more explosions..

KEY ISSUES:
• DUST HAZARD AWARENESS
• DUST LEVEL PERCEPTION

Image credit: CSB

An explosion at the Partridge-Raleigh oilfield in Raleigh, Mississippi. The incident occurred at about 8:30 a.m. on June 5, 2006, when Stringer’s Oilfield Services contract workers were installing pipe from two production tanks to a third. Welding sparks ignited flammable vapor escaping from an open-ended pipe about four feet from the contractors’ welding activity on tank 4. The explosion killed three workers who were standing on top of tanks 3 and 4. A fourth worker was seriously injured.

KEY ISSUES:
• HOT WORK CONTROL
• SAFE WORK PRACTICES AT OIL & GAS PRODUCTION WELLS

ROOT CAUSES:
1. A gas detector was not used to test for flammable vapor.
2. ‘Flashing’ tanks containing hydrocarbons with a lit oxy-acetylene torch to determine the presence of flammable vapor is unsafe and extremely dangerous.
3. The open pipe on the adjacent tank was not capped or otherwise isolated.
4. A makeshift work platform – a ladder placed between the tanks – was used.
5. All tanks were interconnected and some of the tanks contained flammable residue and crude oil.

Image credit: CSB

On June 9, 2009, a major natural gas explosion heavily damaged the ConAgra Slim Jim meat processing factory in Garner, North Carolina, just south of Raleigh. Three workers were crushed to death when a large section of the building collapsed. The explosion critically burned four others and sent a total of 71 people to the hospital including three firefighters who were exposed to toxic anhydrous ammonia from the plant’s refrigeration system. Approximately 18,000 pounds of ammonia were released to the environment and 100,000 square feet of the plant were damaged. Due to the severity of the structural collapse, there was the potential for numerous additional deaths or serious injuries.

KEY ISSUES:
• DIRECTLY VENT PURGED GASES TO A SAFE LOCATION OUTDOORS, AWAY FROM PEOPLE AND IGNITION SOURCES.
• USE COMBUSTIBLE GAS DETECTORS TO MONITOR THE GAS CONCENTRATION DURING PURGING OPERATIONS.
• ENSURE PERSONNEL INVOLVED IN GAS PURGING OPERATIONS ARE FULLY TRAINED.

ROOT CAUSES:
1. Purging into equipment vicinity is common practice

Image credit: CSB

On June 10, 2008, Goodyear operators closed an isolation valve between the heat exchanger shell (ammonia cooling side) and a relief valve to replace a burst rupture disk under the relief valve that provided over-pressure protection. Maintenance workers replaced the rupture disk on that day; however, the closed isolation valve was not reopened.

On the morning of June 11, an operator closed a block valve isolating the ammonia pressure control valve from the heat exchanger. The operator then connected a steam line to the process line to clean the piping. The steam flowed through the heat exchanger tubes, heated the liquid ammonia in the exchanger shell, and increased the pressure in the shell. The closed isolation and block valves prevented the increasing ammonia pressure from safely venting through either the ammonia pressure control valve or the rupture disk and relief valve. The pressure in the heat exchanger shell continued climbing until it violently ruptured at about 7:30 a.m.

The catastrophic rupture threw debris that struck and killed a Goodyear employee walking through the area. The rupture also released ammonia, exposing five nearby workers to the chemical. One additional worker was injured while exiting the area.

KEY ISSUES:
• EMERGENCY RESPONSE & ACCOUNTABILITY
• MAINTENANCE COMPLETION
• PRESSURE VESSEL OVER-PRESSURE PROTECTION

ROOT CAUSES:
1. Although maintenance workers had replaced the rupture disk by about 4:30 p.m. on June 10, the primary over-pressure protection for the heat exchanger remained isolated until the heat exchanger ruptured at about 7:30 a.m. on June 11.

Image credit: CSB

The June 13, 2013 catastrophic equipment rupture, explosion, and fire at the Williams Olefins Plant in Geismar, Louisiana, which killed two Williams employees. The incident occurred during nonroutine operational activities that introduced heat to a type of heat exchanger called a ‘reboiler’ which was offline, creating an overpressure event while the vessel was isolated from its pressure relief device. The introduced heat increased the temperature of the liquid propane mixture confined within the reboiler shell, resulting in a dramatic pressure rise within the vessel due to liquid thermal expansion. The reboiler shell catastrophically ruptured, causing a boiling liquid expanding vapor explosion (BLEVE) and fire.

Process safety management program weaknesses at the Williams Geismar facility during the 12 years leading to the incident caused the reboiler to be unprotected from overpressure.

KEY ISSUES:
• OVERPRESSURE PROTECTION
• PROCESS HAZARD ANALYSIS
• MANAGEMENT OF CHANGE
• PRE-STARTUP SAFETY REVIEW
• OPERATING PROCEDURES
• HIERARCHY OF CONTROLS
• PROCESS SAFETY CULTURE

ROOT CAUSES:
1. Williams did not perform the 2001 MOC until after the plant was operating with the valves installed, and the associated PSSR was incomplete. These actions did not comply with facility (and regulatory) safety management system requirements; however, Williams management accepted both of these practices;
2. Car seals are low-level, administrative controls, but they were the favored safeguard in the 2006 PHA recommendation to prevent overpressure events. Williams Geismar did not have a policy requiring the effectiveness of safeguards to be analyzed;
3. Williams Geismar did not follow OSHA PSM regulatory requirements that operations activities have an associated procedure to safely conduct the work. For example, Williams did not create a procedure specifically for switching the propylene fractionator reboilers Such a procedure should have alerted the operations personnel of the overpressure hazard;
4. The Williams PHA policy did not require effective action item resolution and verification, resulting in incorrect action item implementation in the field;
5. The Williams PHA policy did not require PHA teams to effectively evaluate and control risk; and
6. Operations personnel had informal authorization to manipulate field equipment as part of assessing process deviations without first conducting a hazard evaluation and developing a procedure.

Image & AcciMap Credit: CSB

Three killed when feeding additives bnaphthalene sulfonate to a reaction pool at a chemical fertilizer company.

Proximate causes:
• Failure in following procedure (Improper operation)

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