Bhopal Disaster

The Event: Release of a highly toxic gas from a pesticide production plant that killed thousands of people and impaired the health of hundreds of thousands

Dates: December 2–3, 1984

The escape of methyl isocyanate from a pesticide production plant in Bhopal, India, resulted in the world’s worst chemical disaster. The abandoned plant site, which was not properly remediated, continues to pose an environmental threat to nearby residents by contaminating their drinking-water source.

Union Carbide India, which was jointly owned by Union Carbide and the Indian public, ran a pesticide production plant in Bhopal, a city in central India with a population of approximately one million people. A heavily populated shantytown surrounded the plant. Methyl isocyanate (MIC), a very reactive and toxic chemical used in the production of pesticides, was stored at the plant.

As a cost-cutting measure the facility was understaffed, and the plant workers were poorly trained. The plant’s signage and manuals were in English, but many of the workers were not English speakers. In 1982, U.S. engineers who conducted a safety audit of the plant noted sixty-one hazards in the unkempt facility. Thirty were deemed critical hazards; of these, eleven were found in the MIC/phosgene units. The audit warned that a major toxic release could result.

On the evening of December 2, 1984, the plant was closed for inventory reduction and routine maintenance. Around 11:30 p.m., workers realized when their eyes started to tear and burn that an MIC leak had occurred. They reported the leak to their supervisor and located a section of open piping that they believed to be the source. They took action to contain this presumed source, and the supervisor went on break. By 12:15 a.m., the pressure and temperature in the MIC storage tank had risen to dangerous levels.

When MIC comes into contact with water, a spontaneous reaction results, releasing heat. In the presence of a variety of catalysts, including iron ions, three molecules of MIC will join together to form a trimer. This reaction also releases heat. It is thought that both of these reactions occurred in the MIC storage tank. The heat released during the chemical reactions raised the temperature of the MIC, which increased the rates of the MIC reactions, releasing even more heat. MIC has a low boiling point, and this heat of reaction caused the MIC to vaporize into a gas. The gas expanded, increasing the pressure inside the storage tank until it burst a rupture disk on the line leading to the pressure release valve. When that safety valve was forced open, the gases from the tank began to escape and formed a lethal cloud that moved across Bhopal.

Some people were killed in their sleep by the toxic gas, while others awoke gasping for breath with their eyes and throats burning. The gas cloud quickly spread over an area of 65 square kilometers (25 square miles), engulfing panicked residents who were trying to flee. In a matter of minutes people began to collapse and die. Pregnant women caught in the cloud spontaneously miscarried.

According to the Indian Council of Medical Research, roughly three thousand people were initially killed, and another fifteen thousand later died from chemical-related illnesses. Approximately fifty thousand would suffer permanent disability. All told, the release affected the health of some half a million survivors. Their children represent a second generation of victims, as many have been born with birth defects.

As a result of the Bhopal disaster, India significantly strengthened its regulation of hazardous industries. One of the most important actions the government took was the passage of its Environmental Protection Act of 1986.

A Series of Failed Safeguards

Culpability for the toxic release was found to extend from high levels of management at Union Carbide to workers at the plant. Four months after the disaster, Union Carbide released a report detailing failings that led to the MIC escape. Warren Anderson, the chairman of Union Carbide, acknowledged that conditions at the plant were so poor that it should not have been in operation. The report recounted that sometime before midnight on December 2, 1984, a considerable quantity of water entered the tank and started the heat-releasing reactions. Union Carbide claimed that a disgruntled employee had intentionally introduced the water. Plant workers said it occurred accidentally when water being used to clean pipes leaked into the tank. The tank was equipped with a refrigeration system designed to keep the contents at a low temperature, but it had been shut down months before to cut costs. At the higher storage temperature, the MIC reacted more rapidly with the water.

An alarm that should have sounded when the tank temperature started to rise failed to go off because it had not been reset for the higher storage temperature resulting from the lack of refrigeration. Union Carbide officials hypothesized that the water and high temperature in the tank caused rapid corrosion of its stainless-steel walls. This led to iron contamination that would have catalyzed the heat-releasing trimerization reaction. The temperature in the tank probably rose to at least 200 degrees Celsius (392 degrees Fahrenheit). A control-room operator manually started a sodium hydroxide vent scrubber designed to neutralize leaking MIC, but the sodium hydroxide failed to circulate. The gas rushed to the flare tower, where any MIC escaping the scrubber should have been burned off. This was the last safety control, but it was also out of service. A basic design fault of the plant was that the safety systems were designed to deal with only minor leaks, so even if they had been operative, the volume of gas released would have overwhelmed them.

Although the release started about 12:30 a.m., the plant’s public alarm was not sounded until 2:00 a.m.So many small leaks had triggered it in previous months that the plant had shut it off to avoid disrupting the neighborhood. The local police were informed of the leak only after it had been stopped and after the alarm had been sounded.

An Ongoing Tragedy

The Indian government sued Union Carbide for $3.3 billion but accepted a settlement in February, 1989, that awarded $470 million to the victims. The next of kin of those killed were each awarded $2,000. Each injured survivor received roughly $500, an amount quickly consumed by medical costs. The tens of thousands who could not navigate the process of filing settlement claims or who were too ill to stand in line for hours to register their claims got nothing. The settlement did not address environmental damages.

A lack of clear, continuing corporate liability, combined with negligence on the part of the Indian government, exacerbated the plight of Bhopal residents. Union Carbide and another company that took over the facility in 1994 performed some cleanup but did not fully remediate the 4.5-hectare (11-acre) site. When the state government took over the property in 1998, hundreds of tons of abandoned toxics remained on-site. In addition to toxic wastes dumped at and around the plant, hundreds of tons of pesticides and other chemicals had been left behind in the abandoned facility. The derelict buildings provided insufficient protection against the elements, allowing rainwater to mix with the chemicals and wash them into the soil. Eventually, the contaminants migrated into the groundwater and thus into the water supplies on which residents relied for drinking and washing needs.

In 2001 Dow Chemical acquired Union Carbide. Because Dow had not operated the plant or caused the accident, it would not acknowledge any responsibility to the affected population. Bhopal residents insisted that Dow had purchased not only Union Carbide’s assets but also its liabilities, and they remained unmoved by the contention that Union Carbide’s liability ended with the 1989 settlement.

Bhopal citizens have continued to demand that the American-based Dow remediate the site and address the problems that the abandoned facility has created: poisoned cattle, damaged crops, and an array of human health problems including cancers, neurological disorders, mental illness, and birth defects. The victims have also continued to demand action from their government, which they believe has placed greater priority on India’s economic advancement and positive relations with multinational corporations than on justice. The Indian government renewed efforts in 2011 to extradite Warren Anderson from the United States, but the efforts were unsuccessful. Anderson died in the United States on September 29, 2014, at the age of ninety-two. That same year Bhopal victims’ groups commemorated the thirtieth anniversary of the lethal gas release with vigils and demonstrations.

Bibliography

Amnesty International. Clouds of Injustice: Bhopal Disaster 20 Years On. London: Amnesty Intl., 2004. Print.

Associated Press. “Indians Mark 30th Anniversary of Bhopal Disaster.” MPR News. Minnesota Public Radio, 3 Dec. 2014. Web. 22 Dec. 2015.

Das, Shreyasee, and Shatanjaya Dasgupta. "Hidden Costs of Industrial Disasters: Marriage Market Consequences of the Bhopal Gas Disaster." SSRN, Sept. 2022, papers.ssrn.com/sol3/papers.cfm?abstract‗id=4227143. Accessed 20 Jan. 2023.

De, Sajal, Nalok Banerjee, and Yogesh Sabde. "Respiratory Morbidities and Lung Function Abnormalities in Survivors of Bhopal Gas Disaster: A Cross-Sectional Study." Respiratory Investigation, vol. 60, no. 2, Mar. 2022, pp. 284-292, DOI: 10.1016/j.resinv.2021.09.008. Accessed 20 Jan. 2023.

D’Silva, Themistocles. The Black Box of Bhopal: A Closer Look at the World’s Deadliest Industrial Disaster. Victoria: Trafford, 2006. Print.

Fortun, Kim. Advocacy After Bhopal: Environmentalism, Disaster, New Global Orders. Chicago: U of Chicago P, 2001. Print.

Ganguly, Bani Bandana, Shouvik Ganguly, and Nitin N. Kadam. "Spectrum of Stable and Unstable Rearrangements in Lymphocytic Chromosomes Investigated in Bhopal Population 30 Years Post MIC Disaster Amid Co-Exposure to Lifestyle, Living, and Occupational Hazards." Environmental Science and Pollution Research, vol. 30, 2023, pp. 1997-2019, DOI: 10.1007/s11356-022-22053-5. Accessed 20 Jan. 2023.

Hanna, Bridget, Ward Morehouse, and Satinath Sarangi, eds. The Bhopal Reader: Remembering Twenty Years of the World’s Worst Industrial Disaster. New York: Apex, 2005. Print.

Martin, Douglas. “Warren Anderson, 92, Dies; Faced India Plant Disaster.” New York Times. New York Times, 30 Oct. 2014. Web. 22 Dec. 2015.

Weir, David. The Bhopal Syndrome: Pesticides, Environment and Health. Reprint. Routledge, 2022. Print. Accessed 20 Jan. 2023.