In November 1984, the process safety world was shocked by a devastating incident in Mexico City. A series of gas explosions killed over 500 people. Just 13 days later, an even more horrific event occurred when a toxic cloud descended over a sleeping city in India.
A nightmare scenario was unfolding over the streets of Bhopal in the early hours of Dec. 3, 1984. The world was about to witness the worst-ever industrial incident. Forty years later, the true scale of the tragedy remains uncertain. Estimates suggest up to 5,000 people died that night, with hundreds of thousands suffering long-term health consequences. The full human toll of this catastrophic event continues to haunt the world, with the exact number of fatalities and lifelong illnesses still unknown.
I remember the first time I heard about this incident. I was horrified at the immense loss of life and the sheer scale of the tragedy. It stirred something in me — perhaps a sense of injustice for those lost, or maybe revulsion that, as professional engineers, we bear some accountability for this and other process safety events.
As engineers, we make decisions each day that impact the lives of people we may never meet. Sir Brian Appleton, technical advisor in the 1988 Piper Alpha oil rig explosion inquiry, summed up the need for safety well when he said, “Safety is not an intellectual exercise to keep us in work. It is a matter of our contributions to safety management that determines whether the people we work with live or die.”
Where Bhopal Went Wrong
In 1969, Union Carbide India Limited built a pesticide plant in the city of Bhopal. Over the following decades, the local population near the industrial plant grew. While the facility was modeled after a similar plant in the United States, critical design specifications were systematically compromised. These deviations occurred both during initial design and throughout the plant's operational period, creating significant potential safety risks.
The plant produced and stored Methyl isocyanate (MIC) as an intermediate for further processing. MIC is highly reactive to water and results in a chemical reaction that releases MIC gas. A tank of MIC was contaminated with water and resulted in the gas being released over the town. Unfortunately, over the years, the safety systems had degraded or been actively removed. When the release began, there were no effective safety systems to prevent or contain the incident.
Bhopal's Legacy
There is much we can learn from the Bhopal tragedy from an engineering and process safety perspective. Inherently safer design principles would suggest the MIC should never have been stored at the facility. The facility shouldn’t have been operating without the necessary safety systems installed and functioning to the required performance standards. The equipment should have been installed to the correct specifications, not constructed of inferior product because it was cheaper.
As a process safety professional, I aspire to visit Bhopal one day to honor the victims of that tragic night. This commitment drives my daily work to prevent similar catastrophes. Process safety is crucial to achieving sustainable development goals and protecting workers and communities. The Bhopal disaster serves as a constant reminder that we must continuously improve safety practices in high-hazard industries, ensuring every worker returns home safely.
