Contributory Factors: ORGANIZATIONAL

At approximately 2:00 pm on December 11, 2002, a maintenance employee entered the wastewater treatment (WWT) room at Environmental Enterprises, Inc. (EEI), in Cincinnati, Ohio, to retrieve a tool. His path brought him directly alongside the WWT clarifier, an open-top tank with a conical bottom for settling solids (Figure 1).

As the mechanic approached the clarifier, he noticed a “rotten egg” odor that became stronger as he moved forward. He suddenly felt pressure in his lungs and was unable to breathe. He attempted to flee the area but was overcome by hydrogen sulfide (H2S) gas and collapsed.

Fortunately, fellow employees found the victim a few moments later and pulled him to safety. He recovered, and there were no other injuries. .

KEY ISSUES:
• HAZARD COMMUNICATION
• OPERATING PROCEDURES
• MANAGEMENT OVERSIGHT
• MECHANICAL INTEGRITY

ROOT CAUSES:
1. The facility had no written procedures for operating the WWT area.
2. The operator responsible for the WWT area had no formal training in waste treatment or chemistry.
3. This incident may have been avoided if the operator had been aware of the possible reactions that can produce H2S gas.
4. EEI did not have a formal system for investigating incidents and communicating findings to employees.
5. The facility did not implement procedures or assign responsibilities for calibrating, inspecting, and maintaining the H2S detector.
6. Management oversight could have ensured that then proper treatment methods were used.

Image Credit: CSB

One worker died after hazardous chemical vapors released from an over-pressurized reactor burned his respiratory system. The worker charged chemicals inside a reactor vessel and a reaction started before he could close it.

OSHA’s proposed penalties total $87,780

Proximate causes:
• 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: Google Maps

An explosion severely injured a graduate student at Texas Tech University in Lubbock, Texas, in the chemistry department during the handling of a high-energy metal compound, which suddenly detonated. Texas Tech had entered into an agreement with Northeastern University, which holds a contract from the U.S. Department of Homeland Security to study the high-energy materials.

KEY ISSUES:
• LABORATORY SAFETY MANAGEMENT FOR PHYSICAL HAZARDS
• HAZARD EVALUATION OF EXPERIMENTAL WORK IN RESEARCH LABORATORIES
• ORGANIZATIONAL ACCOUNTABILITY & OVERSIGHT OF SAFETY

Image & AcciMap 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

On January 13, 2003, at approximately 4:30 pm, a vapor cloud deflagration and pool fire erupted at the BLSR Operating, Ltd. (BLSR), facility located 5 miles north of Rosharon, Texas. Two BLSR employees were killed, and three were seriously burned. Two T&L Environmental Services, Inc. (T&L), truck drivers, who had just delivered gas condensate storage tank basic sediment and water (BS&W) to BLSR, were seriously burned; one of these men died on March 2.

The fire was caused by the release of hydrocarbon vapor during the unloading of BS&W from two vacuum trucks into an open area collection pit. BS&W is an oil/gas exploration and production (E&P) waste liquid. The fire destroyed two 50-barrel (2,100-gallon) vacuum trucks and seriously damaged waste liquid offloading equipment and structures at BLSR. One of the vacuum truck diesel engines was the most likely source of ignition..

KEY ISSUES:
• RECOGNIZING FLAMMABILITY HAZARDS OF EXPLORATION & PRODUCTION WASTE LIQUIDS
• SAFE HANDLING OF FLAMMABLE LIQUIDS

ROOT CAUSES:
1. Noble Energy, Inc., the shipper, failed to identify the flammability hazard of BS&W generated at its gas well production facility, and also failed to communicate the hazard to employees and contractors who were required to handle the flammable liquid.
2. T&L management did not require Noble Energy to provide vacuum truck drivers with a material safety data sheet or other document listing the potential flammability hazard of BS&W, nor did it identify the flammability hazard of the mixture in the vacuum truck tank.
3. BLSR management did not have effective hazard communication practices in place to recognize the potential flammability hazard of each shipment of BS&W, nor did it implement safe handling practices when offloading flammable liquid onto the mud disposal and washout pad area.

Image Credit: CSB

On January 16, 2002, highly toxic hydrogen sulfide gas leaked from a sewer manway at the Georgia-Pacific Naheola mill in Pennington, Alabama. Several people working near the manway were exposed to the gas. Two contractors from Burkes Construction, Inc., were killed. Eight people were injured–seven employees of Burkes Construction and one employee of Davison Transport, Inc. Choctaw County paramedics who transported the victims to hospitals reported symptoms of hydrogen sulfide exposure.

KEY ISSUES:
• REACTIVE HAZARD IDENTIFICATION
• HYDROGEN SULFIDE SAFETY
• EMERGENCY RESPONSE

ROOT CAUSES:
1. Good engineering and process safety practices were not followed when joining the drain from the truck unloading station and the oil pit to the acid sewer.
2. There was no management system to incorporate hazard warnings about mixing sodium hydrosulfide (NaSH) with acid into process safety information.

Image Credit: CSB

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

On January 29, 2003, an explosion and fire destroyed the West Pharmaceutical Services plant in Kinston, North Carolina, causing six deaths, dozens of injuries, and hundreds of job losses. The facility produced rubber stoppers and other products for medical use. The fuel for the explosion was a fine plastic powder, which accumulated above a suspended ceiling over a manufacturing area at the plant and ignited.

KEY ISSUES:
• HAZARD RECOGNITION & COMMUNICATION
• GOOD ENGINEERING PRACTICE
• LOCAL AMENDMENTS TO FIRE CODES

ROOT CAUSES:
1. West did not perform adequate engineering assessment of the use of powdered zinc stearate and polyethylene as antitack agents in the rubber batchoff process.
2. West engineering management systems did not ensure that relevant industrial fire safety standards were consulted.
3. West management systems for reviewing material safety data sheets did not identify combustible dust hazards.
4. The Kinston plant’s hazard communication program did not identify combustible dust hazards or make the workforce aware of such.

Image Credit: CSB

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

This incident occurred at Synthron, LLC’s Morganton, North Carolina, facility. The company manufactured a variety of powder coating and paint additives by polymerizing acrylic monomers in a 1,500 gallon reactor.

The company had received an order for slightly more of an additive than the normal size recipe would produce. Plant managers scaled up the recipe to produce the required larger amount of polymer, and added all of the additional monomer needed into the initial charge to the reactor. This more than doubled the rate of energy release in the reactor, exceeding the cooling capacity of the reactor condenser and causing a runaway reaction.

The reactor pressure increased rapidly. Solvent vapors vented from the reactor’s manway, forming a flammable cloud inside the building. The vapors found an ignition source, and the resulting explosion killed one worker and injured 14. The blast destroyed the facility and damaged off-site structures.

KEY ISSUES:
• REACTIVE HAZARDS & SAFEGUARDS
• CORPORATE OVERSIGHT
• SAFE OPERATING LIMITS
• EVACUATION PLANNING & DRILLS

ROOT CAUSES:
1. A lack of hazard recognition.
2. Poorly documented process safety information & ineffective control of product recipe changes.
3. Lack of automatic safeguards to prevent or mitigate the effects of loss of control over the reaction.
4. Improper manway bolting practices and poor operator training.
5. Inadequate emergency plans drills.
6. Inadequate corporate oversight of process safety.

Image credit: CSB

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

Three combustible dust incidents over a six month period occurred at the Hoeganaes facility in Gallatin, TN, resulting in fatal injuries to five workers. The facility produces powdered iron and is located about twenty miles outside of Nashville.

KEY ISSUES:
• HAZARD RECOGNITION AND TRAINING
• ENGINEERING CONTROLS
• FIRE CODES/ENFORCEMENT
• REGULATORY OVERSIGHT

ROOT CAUSES:
1. Hoeganaes facility management were aware of the iron powder combustibility hazard two years prior to the fatal flash fire incidents but did not take necessary action to mitigate the hazard through engineering controls and housekeeping.
2. Hoeganaes did not institute procedures – such as combustible gas monitoring – or training for employees to avoid flammable gas fires and explosions

Image credit: CSB

On February 2, 2001, a fire occurred at Bethlehem Steel Corporation’s Burns Harbor mill in Chesterton, Indiana. One Bethlehem Steel millwright and one contractor supervisor died. Four Bethlehem Steel millwrights were injured, one seriously. Workers were attempting to remove a slip blind and a cracked valve from a coke oven gas line leading to a decommissioned furnace. During removal of the valve, flammable liquid was released and ignited.

KEY ISSUES:
• MAINTENANCE JOB PLANNING
• FACILITY WINTERIZATION & DEADLEGS
• LINE & EQUIPMENT OPENING
• DECOMMISSIONING & DEMOLITION

ROOT CAUSES:
1. Management systems for the supervision, planning, and execution of maintenance work were inadequate.
2. The Burns Harbor facility did not have a system for monitoring and controlling hazards that could be caused by changes in COG condensate flammability or accumulation rates.

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

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

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

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

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

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

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