Hazards: Toxic

A tank ruptured in Warsaw Chemical company, it contained hazardous chemical that caused a fire followed by an explosion. After the fire some chemicals spilled into Winona lake.

50 homes were evacuated

Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)
Image Credit: 1480 News Now

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)

A hairline crack in a welded seam of piping to the level indicator system on an aldehyde column resulted in a minor ethylene oxide leak on this gas processing plant. As a result of this crack, which was caused by low cycle fatigue, ethylene oxide escaped near the level indicator and formed polyethylene glycols (PEG) in the mineral wool insulation. It is believed that both the leak and accumulation of PEG occurred over a period of time. During repairs to the level indicator, the metal sheathing of the insulation was removed and air contacted the insulation soaked with PEG. Auto-oxidation of the PEG resulted and the insulating material was ignited. The piping to the level indicator system was heated to such a degree that auto-decomposition of the ethylene oxide within the piping occurred. This autodecomposition propagated into the aldehyde column which subsequently exploded. The force of the explosion completely destroyed the distillation section of this plant. The large resulting fire and impact of flying debris to other process sections resulted in extensive damage throughout the plant.

[ Property Damage $79 Million. Estimated Current Value $178 Million ]

Image credit: No credit

An explosion occurred in the ethylene oxide process unit at this plant. As a result, the ethylene oxide refining column was completely destroyed, the ethylene glycol unit was substantially damaged, and the co-generation unit was partially damaged. A pipe rack near the storage area for liquid ethylene oxide was damaged when a large piece of shrapnel from the explosion hit the rack, rupturing lines which contained methane and other hydrocarbon products.

The subsequent fire that resulted from the released products was the only significant fire to occur during this incident. As a result of the explosion, all utilities at the plant were lost for approximately one week. Additionally, several fixed fire protection systems were damaged by the explosion or inadvertently actuated due to a loss of plant air. These systems were shut off, isolated, or placed back in service, as appropriate. A manual fire fighting effort was used to extinguish the fire in the pipe rack once the lines in the rack were isolated. The polyethylene production was restarted in early April 1991 using imported ethylene. The olefins production unit was restarted in late April 1991.

[ Property Damage $90 Million. Estimated Current Value $194 Million ]

Image credit: Vitaly Shmatikov

On 20 March 1990 the halogen exchange reactor on the Fluoroaromatics plant was ruptured by the pressure generated by a runaway reaction. The plant was partially destroyed and missiles were projected over 500m. Six employees were injured and one subsequently died from post-operative complications.

A batch had been charged into the vessel and was being heated up as normal. When it reached 165oC, the temperature continued to rise and the operators adjusted the jacket temperature. The display screen in use did not display pressure and they were unaware of a corresponding rise in pressure. By the time they were alerted to the rise in pressure the pressure relief valves had lifted. Before any other corrective action could be taken, the reactor exploded. The pressure in the vessel reached a value of about 60-80 barg compared with the relief valve set pressure of 5 barg.

The resulting blast was enhanced by the formation of a fireball, which occurred when the contents of the reactor ignited within the plant structure. This started local fires and initiated what became a major conflagration in an adjacent unit where vessels containing xylene were damaged by the blast/missile effects. The ensuing fires were brought under control in four hours by the Shell fire team and Cheshire fire service.

The initial cause of the incident was the ingress of excessive water into the process leading to the formation of acetic acid which, upon recycle to the reactor, reacted vigorously with the reactor contents initiating the explosion. Water was present as a part of the process, however a massive incursion led to the formation of a separate layer in the process vessel which was not removed but recycled back into reactor.

KEY ISSUES:
• CONTROL ROOM DESIGN
• RAW MATERIALS CONTROL / SAMPLING
• REACTION / PRODUCT TESTING
• RELIEF SYSTEMS / VENT SYSTEMS

Image Credit: The Leader

On April 8, 1998, an explosion and fire occurred during the production of Automate Yellow 96 Dye at the Morton International Inc. plant in Paterson, New Jersey. The explosion and fire were the consequence of a runaway reaction, which overpressurized a 2000-gallon chemical vessel and released flammable material that ignited. Nine employees were injured.

KEY ISSUES:
• INTERNAL HAZARD COMMUNICATION & PROCESS SAFETY INFORMATION
• REACTIVE HAZARD MANAGEMENT
• PROCESS SAFETY MANAGEMENT

ROOT CAUSES:
1. Neither the preliminary hazard assessment conducted by Morton in Paterson during the design phase in 1990 nor the process hazard analysis conducted in 1995 addressed the reactive hazards of the Yellow 96 process.
2. Process safety information provided to plant operations personnel and the process hazard analysis team did not warn them of the potential for a dangerous runaway chemical reaction.

Image Credit: CSB

Two employees accidently fell in an aerobic tank sewage treatment station. Two more employees fell into the aerobic tank in the subsequent rescue.

Proximate causes:
• Inadequate tools, equipment & vehicles (Aerobic tank no special ventilation equipment)

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

An April 11, 2003, vessel explosion at the D.D. Williamson & Co., Inc. (DDW), plant in Louisville, Kentucky, killed one operator. The explosion damaged the western end of the facility and released 26,000 pounds of aqua ammonia (29.4 percent ammonia solution in water), forcing the evacuation of as many as 26 residents and requiring 1,500 people to shelter-in-place.

DDW used the vessel in the manufacture of food-grade caramel coloring. It functioned as a feed tank for a spray dryer that produced powdered colorants. The feed tank, which was heated with steam and pressurized with air, was operated manually. To ensure that the filling, heating, and material transfer processes stayed within operating limits, operators relied on their experience and on readouts from local temperature and pressure indicators.

The feed tank most likely failed as a result of overheating the caramel color liquid, which generated excessive pressure. .

KEY ISSUES:
• OVERPRESSURE PROTECTION
• HAZARD EVALUATION SYSTEMS
• LAYERS OF PROTECTION
• OPERATING PROCEDURES & TRAINING

ROOT CAUSES:
1. D.D. Williamson did not have effective programs in place to determine if equipment and processes met basic process and plant engineering requirements.
2. D.D. Williamson did not have adequate hazard analysis systems to identify feed tank hazards, nor did it effectively use contractors and consultants to evaluate and respond to associated risks.
3. D.D. Williamson did not have adequate operating procedures or adequate training programs to ensure that operators were aware of the risks of allowing the spray dryer feed tanks to overheat and knew how to respond appropriately.

Image Credit: CSB

A fire occurred in a company producing ammonia, and other chemical products. The facility was severely damaged in the catastrophic fire.

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

On April 23, 2004, an explosion and fire killed five and seriously injured three workers at the Formosa Plastics Corporation, IL (Formosa-IL) PVC manufacturing facility in Illiopolis, Illinois. The explosion occurred after a large quantity of highly flammable vinyl chloride monomer (VCM) was inadvertently released from a reactor and ignited. The explosion and fire that followed destroyed much of the facility and burned for two days. Local authorities ordered residents within one mile of the facility to evacuate.

KEY ISSUES:
• HUMAN FACTORS
• HAZARD EVALUATION
• INCIDENT INVESTIGATION
• EMERGENCY RESPONSE

ROOT CAUSES:
1. Borden Chemical did not adequately address the potential for human error.
2. Formosa-IL did not adequately address the potential for human error.
3. Formosa-IL relied on a written procedure to control a hazard with potentially catastrophic consequences.

Image Credit: CSB

Bulk Terminals was a storage tank farm with 78 tanks ranging in size up to 4900 m3. At about 12:30 hours on Friday 26 April 1974 a dull thud was heard and fumes were seen rising from the bund surrounding a 3300 m3 tank of silicon tetrachloride. It was discovered that a pressure relief valve on a 6-inch line leading to the tank had been inadvertently closed. The pressure in the system was sufficient to burst a flexible coupling in the line, shifting the piping system and cracking a 3-inch line on the tank wall. Liquid silicon tetrachloride escaped forming an irritant cloud containing hydrogen chloride gas.

The terminal management waited for the owners of the chemical to take emergency action and the fire service did not respond, as there was no fire. The EPA sent lime trucks to neutralise the chemical, but these were refused entry to the site. By 15:00 hours the cloud was 400 m wide, 300-450 m high and 1600 m long.

At 04:10 hours on Saturday 27 April, foam was added to blanket the liquid in the bund but this failed. At 09:00 hours fuel oil was added along with eight truck loads of lime. The vaporisation reduced dramatically and operations began to transfer the liquid from the damaged tank. At 08:00 hours on Sunday 28th April, it began to rain. Power lines were corroded by the hydrochloric acid in the rain, and four pumps became inoperable due to corrosion before a general power failure stopped all pumping.

The materials added into it had reduced the capacity of the bund, and a further pit had to be dug to take the overflow in the event of a full tank failure. It was attempted to seal the leak on the tank using quick drying cement. The first attempt failed and it wasn’t until 23:30 hours on Monday 29 April that the leak was sealed. It took until 3 May to empty the tank and until 15 May before emissions had reduced to tolerable levels. One person was killed, 160 hospitalised and 16,000 people were evacuated during this incident.

KEY ISSUES:
• RELIEF SYSTEMS / VENT SYSTEMS
• DESIGN CODES – PIPEWORK
• EMERGENCY RESPONSE / SPILL CONTROL
• SECONDARY CONTAINMENT

Image Credit: Chicago Fire Dept

Workers were preparing to check a compressor in the nitroparaffin unit when they noticed a small fire and sounded the plant fire alarm. About 30 seconds later, an explosion occurred, which was followed by a series of smaller explosions. The effects of the initial explosion were reported as far away as eight miles from the plant. Additionally, the initial explosion completely damaged an area of the plant approximately the size of a city block. Subsequent fires were reported to have burned for more than seven hours. Although the incident did not damage the two ammonia units on site, the entire plant was temporarily shut down for precautionary measures.

[ Property Damage $120 Million. Estimated Current Value $257 Million ]

Image credit: No credit

Ammonia release at recycling center workers was evacuated. Shelter in place was issued in nearby areas.

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

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

An epoxyethane device got exploded and then triggered a fire. The fire spread to three of six chemical tanks nearby. Each tank has a storage capacity of 1000 cubic meters. More than 200 fire fighters arrived at the site to put out the fire.

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

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)

A tank containing chlorine exploded at the Olin Chlor Alkali Products plant in Becancour. Workers in nearby buildings were evacuated, but employees at Olin Chlor Alkali were told to remain at the chemical plant.

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

On the morning of Sunday 27 June 1982 two explosions occurred at the premises of Staveley Chemicals Limited. The source of the explosions was a pit containing drums of sulphur trioxide and of oleum. The drums of sulphur trioxide had been returned from customers more than 10 years previously and had then been stored in the open. Over the following years minor leaks developed through corrosion, and sulphur trioxide vapour began to escape as a visible fume. In November 1981 the company decided to overcome the problem by surrounding the drums with an absorbent solid. A pit was dug out on some open land within the works site, the drums placed within the pit, then covered over with a proprietary absorbent material and topped with crushed blast furnace slag. No special provision was made for drainage of the pit, nor to prevent ingress of ground water or rain. Drums of oleum were included together with the drums of sulphur trioxide in the pit.

The first explosion occurred at 10:45 hours on June 27th. Two drums were blown out of the site, over a public highway, to fall into open ground outside the works boundary and about 300 metres from the containment pit. Fortunately no injury to persons or damage to property was caused by these events. Further, but less intense explosions continued until the following day. A cloud of white acid mist billowed up from the site.

The Fire Brigade could not use water hoses because of the possibility of causing a violent reaction with any escaping oleum or liquid sulphur trioxide within the containment pit. It was decided that the best immediate course of action would be to put anhydrous sodium sulphate powder into the open pit in order to absorb liquid and suppress fuming. Several bags of this powder were thrown in and by 12:00 hours the mist emission was lessening. However, a second explosion occurred at 12:30 hours with a large release of acid mist but without ejecting any drums. There was a third explosion at about 14.30 hours. Tarpaulins were put over the pit to prevent the ingress of rain. The last explosion was at about 03:00 hours, the following morning. This explosion was minor compared with those on the previous day.

On Monday 28 June, a heavy steel grid was placed over the pit to reduce the risk of further drums being ejected. Temperature measurements were made in the pit, and found to be as high as 90°C in places. Subsequently the drums were all taken out of the pit and put on to open ground nearby. There were 32 sound drums remaining, and 25 corroded and empty or nearly empty.

KEY ISSUES:
• DRUM / CYLINDER HANDLING

Image Credit: YouTube (Hollingwood Lad)

An explosion and fire was caused by the failure of ammonia synthesis equipment

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