Fire and Chemical Disasters

¶ … Hazardous Materials Incident

Key Lessons for Preventing Hydraulic Shock and New Cumberland, WV Metal Dust Explosion and Fire are two case studies that will be examined in this report. One examines a metal dust explosion and fire and the other involves a pipe that catastrophically failed thus leading to the release of more than 32,000 pounds of anhydrous ammonia. Each also gives formal detailed reports on significant chemical accidents and include key findings, root causes, and safety recommendations. With that said, this essay will summarize the findings of each investigation, and compare and contrast the two incidents with respect to the chemicals involved, underlying hazards, accident causes, and recommendations from the CSB.

Casse study one: The New Cumberland, West Virginia Fire Explosion

This case study examines a metal dust explosion and fire at the AL Solutions facility in New Cumberland, West Virginia. The incident resulted in three employee fatalities and one contractor injury. The explosion and ensuing fire damaged the production building and ultimately caused the shutdown of the plant.

Background

The New Cumberland production facility is a place that was operated all day everyday 7 days a week non-stop. The company had processing equipment for metal milling, blending, pressing, and treatment for water. A normal shift, involved four operators that managed the production building which involved the following: two press operators, one blender operator, and the shift supervisor. Usually, the shift supervisor was in charge of the water treatment and mill. When it was about 12 noon, on the day of the disaster, the day shift operators came back to work from lunch. At this time, two operators were operating the three presses making titanium and zirconium compacts, and another operator was at the blender, blending a batch of zirconium. When the clock struck 1:20 P.M., directly before the outburst, an electrical contractor spotted around 6 feet outside a partly open door heard a loud noise that he described to U.S. Chemical Safety and Hazard Investigation Board (CSB) investigators as a "metallic failure & #8230; like something popped & #8230; or fell." (AL Solutions Case Study, 2010)

Casse study Two: Millard Refrigerated Hydraulic Shock Catastrophe

This case study examines the shock disaster that took place at Theodore, Alabama, On August 23, 2010, at the Millard Refrigerated Company. A roof-attached 12-inch suction pipe to disastrously fail leading to the release of over and above 32,000 pounds of ammonia.

Background

In a moment before 9:00 AM on the daybreak of August 23, 2010, the company was in the development of trying to load two global ships that contained frozen chickens when the facility's refrigeration system hit a hydraulic shock incident that caused a catastrophic piping system to completely just shutdown out of nowhere thus releasing some 32,100 pounds of anhydrous ammonia in the air. The bulk of the fumes from ammonia discharged in this incident happened through a compromised share of the system's 12-inch suction pipe positioned on the rooftop. The stemming mist of ammonia gas traveled 0.25 miles to the south across the Theodore Industrial Canal, exposing a Millard employee and offsite contractors working outdoors (Hydraulic Shock Safety Bulletin, 2015). At around the same time, alarms went off all over the place within the plant because of the detection of high concentrations of ammonia in doors by air-monitoring apparatus in the freezers. The ammonia noticed within the facility was the outcome of a second leak that occurred for the reason that a portion of the system's blast freezer evaporator header ruptured (Hydraulic Shock Safety Bulletin, 2015).

Hazards

It is clear that case study one, hazards were because of a lot of dust that that piled up over a long period of time. For example, the case study explored that most solid organic materials (and numerous metals and some nonmetallic inorganic materials) will explode or burn if delicately divided and distributed in adequate dilutions. Even apparently small amounts of collected dust can cause catastrophic injury. Eliminating any one of these basics of the classic fire triangle eradicates the likelihood of a fire. However, it was different in case study two because mixing together chemicals at high speed was dangerous, especially if not monitored properly was the issue. The failure at Millard was likely caused by a mixture of concentration prompted shock and vapor-propelled liquid. One thing that is similar in both cases is that the hazards were things that were overlooked for long periods of times.

Accident Causes

Case study one had particular kinds of metals that were just rusting away over time which basically caused the explosion. For example, exceptionally divided metals for example titanium and zirconium can turn out to be pyrophoric12 and suddenly combust in air. Also, in case one, the blender blades were also full of dust and were rusting away. There was crack in the sidewall of the blender and it had a substantial quantity of zirconium on it which were dust particles that led to explosion (AL Solutions Case Study, 2010). The blade was never cleaned or replaced.

However, in case study two because the operator physically interfered to clear the alarm and as a result reset the control system, the control system was not able to recognize that the blast freezer evaporator unit controlled high-pressure hot gas when it permitted the suction stop valve to open all through the system pick up. Somewhat, the control system was able to signal the suction stop valve and liquid feed valves to at the same time open with the intention of returning the evaporator to cooling mode procedure. This manual sidestep of the programmed defrost sequence endorsed the low-temperature liquid and hot gas to mix in the same pipe, instigating the hot gas emptiness to breakdown as it quickly reduced to a liquid. This shaped pressure shocks that cracked the evaporator piping manifold and the low-temperature force piping on the roof (Hydraulic Shock Safety Bulletin, 2015). In Millard's investigation report for the 2010 event, the corporation discovered that the guidebook clearing of an ammonia alarm in the control system disturbed the defrost sequence. This was allowed by a lack of limited access to control system alterations. Case one involved titanium and zirconium as the causes whereas case two it was partly because the alarm system failed.

Recommendations from the CSB

For case study one, the CSB told OSHA that it should issue a general industry standard for the prevention of combustible dust fires and explosions, founded on the current NFPA dust ethics. They also suggested to issue a standard designed to prevent flammable dust fires and detonations in general industry. CSB also suggested that they base the standard on current National Fire Protection Association (NFPA) dust explosion ideals (including NFPA 654 and NFPA 484), and include at least - hazard assessment, - engineering controls, - housekeeping, - building design, - explosion protection, - operating procedures, and - worker training (AL Solutions Case Study, 2010). CSB wanted to develop training materials that speak to combustible dust hazards and plant definite metal dust hazards and then train all contractors and employees. CSB wanted and made the suggestion that all require some kind of periodic refresher training for all employees and contractors.