The Bhopal Disaster of 1984 is widely regarded as the worst industrial disaster in human history. The disaster involved a massive chemical leak from a methyl isocyanate processing plant, and a toxic cloud of dangerous chemicals that flowed through the densely populated areas around the plant.
Over four thousand people were killed and hundreds of thousands were crippled with life-long symptoms of the exposure to the toxic chemicals.
The entire incident occurred on the night of December 2, 1984 at the Union Carbide India Limited pesticide plant in Bhopal, Madhya Pradesh, India. The factory was built in 1969 to produce the pesticide Sevin. A methyl isocyanate production plant was later added in 1979.
Bhopal gas crisis started when water leaked into a tank containing 42 tons of methyl isocyanate, which resulted in an exothermic reaction that increased the temperature inside the tank to over 200 °C (392 °F). Reaction pressurized the tank to the point of venting the gases out into the atmosphere.
The deadly gas cloud problem
Since most of the gases were heavier than air, the resulting toxic death cloud fell promptly to the ground. Northwesterly winds over Bhopal blew the toxins through the city of like a gaseous tidal wave, maiming all directly exposed and contaminating the surrounding environment for decades to come. The problem was made worse by many slums in the vicinity of the plant and general lack of catastrophe plans. Shortcomings in health care and socio-economic rehabilitation proved fatal for many of the people who found themselves in the vicinity of the gas cloud.
Root cause of plant failure has been somewhat controversial and obscured due to corporate interference even to this day. The company that owned the plant, Union Carbide Corporation, took advantage of the corruption in the Indian government. The highly deregulated industry laws of the nation and the lack of education and voice amongst the local population allowed them to minimize the safety costs and maintenance procedures, thus maximizing profit from the production achieved at the plant.
The magnitude of the gas leak was great because methyl isocyanate was stored in large tanks which were often filled beyond recommended levels. Poor maintenance caused the failure of several safety systems, since safety manuals were in English and only several workers actually understood them. Final fatal mistake was switching off the safety systems to save money. Methyl isocyanate tank refrigeration system was among turned off systems and even though it wouldn't prevent the disaster, it would have certainly mitigated the Bhopal crisis severity.