3 Ways Loss of Containment Incidents Impact People and the Environment

Introduction

Chemical releases, fires, and explosions are among the most severe consequences of process hazards in the chemical industry, often resulting in catastrophic outcomes for both people and the environment. They are grouped under loss of containment (LOC), representing the largest category of process safety incidents. LOC encompasses a spectrum from minor releases of relatively harmless substances to catastrophic events involving substantial releases of hazardous materials and/or energy.

According to the U.S. Chemical Safety Board (CSB), LOC may result directly from equipment failure or operational issues or indirectly from process events, such as pressure buildup, runaway reactions, or dust deflagrations, which can lead to emergency venting or loss of vessel integrity.

Saltegra Consulting LLC, as a HAZOP provider based in California, offers expert consultants and facilitators to help organizations mitigate these risks and protect both human life and the environment from catastrophic incidents. This article delves into common LOC scenarios, offering definitions, detailed descriptions, and their impacts while highlighting historical examples to emphasize their severity.

Chemical Releases

Leaks and Spills

According to the U.S. Environmental Protection Agency (EPA), oil and chemical spills involve the accidental release of hazardous substances. These incidents can occur due to equipment failure, improper handling, or human error, resulting in the uncontrolled discharge of hazardous materials.

Oil and chemical spills can vary widely in scale and impact. The CSB has documented numerous incidents where such spills have led to significant safety hazards. For example, the CSB reported on a leak at the Tesoro Refinery  in Martinez, California, in 2014, where sulfuric acid was released due to pipe corrosion, resulting in worker injuries.

One significant example of an oil spill is the Deepwater Horizon oil spill in 2010. In the Gulf of Mexico, a blowout on the Deepwater Horizon drilling rig caused the release of millions of barrels of crude oil into the ocean. The spill had devastating effects on marine life and coastal ecosystems, with long-term economic and environmental impacts.

Another notable chemical spill occurred in 2014 in Elk River, West Virginia, where a tank at a chemical storage facility leaked 4-methylcyclohexanemethanol (MCHM) into the river, contaminating the water supply for 300,000 residents. The spill raised significant public health concerns and led to widespread water use restrictions.

Gas Releases

A gas release, as defined by the Center for Chemical Process Safety (CCPS) Guidelines for Chemical Process Quantitative Risk Analysis, is a loss of containment where hazardous gases are discharged into the environment. These releases can occur due to equipment failure, operational errors, or process events such as pressure buildup or runaway reactions. Such incidents can lead to severe safety hazards and significant environmental and health impacts.

Unlike leaks and spills, gas releases can disperse more rapidly, affecting large areas and populations. The CSB has investigated incidents like the 2010 gas release at the Horsehead Zinc Plant in Pennsylvania, where a furnace malfunction caused a significant release of carbon monoxide, leading to worker fatalities and injuries.

One of the most catastrophic chemical spills in history is the Bhopal Disaster of 1984. In Bhopal, India, a leak of methyl isocyanate gas from a pesticide plant exposed over 500,000 people to the toxic chemical. Immediate deaths were estimated in the thousands, with long-term health effects including respiratory problems, blindness, and birth defects affecting hundreds of thousands. The environmental impact of gas releases can be profound, particularly when involving toxic substances. The gas leak from the Union Carbide plant in Bhopal not only caused immediate human casualties but also resulted in long-term soil and water contamination, disrupting ecosystems and livelihoods.

The Bhopal tragedy was a major contributing factor to the widespread adoption of PHA techniques not just in the oil and gas industry but also in other sectors. This is why HAZOP and other PHA methodologies are required for oil and gas companies, as well as other facilities that process hazardous chemicals or substances.

Fires

Pool Fire

A pool fire occurs when a flammable liquid spills and ignites, creating a fire that burns over a liquid surface pool. This type of fire is particularly hazardous in areas where large quantities of flammable liquids are stored or handled.

Pool fires are common in industrial settings, especially on tank farms. They can result from leaks, spills, or failures in containment systems. The CSB has investigated several incidents involving pool fires, such as the 2005 BP Texas City Refinery explosion, where a large pool fire occurred following the initial blast.

Pool fires pose significant risks to human health through burns, smoke inhalation, and secondary explosions. They can cause extensive environmental damage by burning off vegetation, releasing toxic fumes, and contaminating water sources with runoff from firefighting efforts.

Jet Fire

A jet fire occurs when a flammable gas or liquid is released under pressure and ignites, creating a high-energy, directional flame. These fires are particularly dangerous due to their intensity and the difficulty in controlling the direction of the flame.

They are often associated with high-pressure gas systems. The CSB has reported on incidents like the 2009 Silver Eagle Refinery explosion in Utah, where a high-pressure gas leak resulted in a jet fire.

Jet fires can result in severe burns and fatalities. The high energy of the flame can also lead to structural damage, increasing the risk of secondary incidents. Environmental impacts of jet fires include the destruction of nearby vegetation, wildlife habitat loss, and air pollution from the combustion of hydrocarbons. 

Explosions

Vapor Cloud Explosion

A vapor cloud explosion (VCE) occurs when a dispersed cloud of flammable vapor ignites, causing a violent explosion. These explosions are particularly hazardous in areas where flammable gases are processed or stored.

VCEs typically happen when there is a large release of flammable gas that mixes with air and finds an ignition source. The resulting explosion can cause widespread destruction. The CSB has investigated incidents such as the 2010 Tesoro Anacortes Refinery explosion, where a vapor cloud formed and ignited, causing multiple fatalities.

The Texas City Refinery explosion in 2005 is a prominent example. A vapor cloud explosion during the startup of a hydrocarbon isomerization unit resulted in 15 deaths and 180 injuries, illustrating the lethal potential of VCEs.

The environmental damage from VCEs can be extensive, including fires that follow the explosion, contamination from the chemicals involved, and long-term impacts on air and water quality.

Boiling Liquid Expanding Vapor Explosions

A boiling liquid expanding vapor explosion (BLEVE) occurs when a vessel containing a pressurized liquid is heated, causing the liquid to vaporize rapidly and the vessel to rupture, often leading to an explosion and fire. These incidents are particularly dangerous in industrial settings with pressurized tanks.

The rapid release of energy can cause massive destruction and significant casualties. The intense heat and force of the explosion can lead to fatalities and severe injuries, as seen in various industrial accidents. The environmental impact of BLEVEs includes fires that can spread rapidly, the release of toxic substances, and the long-term contamination of the affected area.

Fireballs occur when a large amount of flammable liquid or vapor is rapidly released and ignited, forming a spherical fire that rises into the air. The size of the fireball depends on the mass of the fuel released. A fireball can occur, for example, after a BLEVE. To prevent such an incident, HAZOP and other PHA methodologies need to be conducted in oil and gas plants to assess and mitigate risks as needed.

Conclusion

Chemical releases, fires, and explosions pose significant risks to both people and the environment. Understanding these incidents’ causes, impacts, and historical examples is crucial for developing effective safety measures and response strategies.

Preventing LOC incidents requires a comprehensive approach that includes identifying and assessing chemical hazards, managing potential risks, and implementing appropriate safeguards. Conducting Hazard and Operability Studies (HAZOP) with the help of an expert facilitator from California or other parts of the USA can help identify potential consequences and recommend appropriate safeguards. Regular maintenance and inspection of equipment, thorough training for personnel, and effective emergency response planning are essential components. Additionally, fostering a culture of safety and continuous improvement through learning from past incidents can significantly reduce the likelihood and impact of LOC events.

Saltegra Consulting LLC, a HAZOP provider based in California, offers expert facilitators and consultants to guide organizations in mitigating risks and protecting both human life and the environment from catastrophic incidents.