Bhopal Disaster

In 1984, the worst industrial accident in world history took place in Bhopal mainly due to leakage of chemicals. The reason behind the tragedy was gas leak and the Bhopal gas tragedy gas name is methyl isocyanate. The Bhopal gas tragedy date is 03rd December 1984. On that date, about 45 tons of the dangerous gas methyl isocyanate discharged from the insecticide plant and became the reason for the Bhopal gas tragedy. 

The Bhopal disaster happened in the Indian subsidiary company, which was owned by the American firm Union Carbide Corporation.  Within a few hours of chemical leakage, the toxic gas spread over miles and killed thousands of people in its surrounding area. This article explains the cause, impact and long term effects of the Bhopal gas leak in detail. 

About UCIL 

In 1986, the UCIL factory was set up to produce the pesticide Sevin using the intermediate chemical methyl isocyanate at Bhopal, Madhya Pradesh. In 1979, the UCIL site constructed the methyl isocyanate production plant. Here, the methylamine reacts with phosgene to produce methyl isocyanate. After 1890, the demand for pesticides fell. So, the factory started to store the unused methyl isocyanate in an improper way.  For some reasons, the dangerous chemical methyl isocyanate leaked and killed thousands of employees and surrounding residents within a few hours. Also, people who have not died were affected by cancers, blindness, loss of livelihood, and financial strain.

UCIL Previous Leakage 

UCIL has previously faced many complaints and requests from the public regarding its maintenance. In 1976, two local trade unions raised complaints about the pollutants created by plants. In 1981, one of the employees of UCIL accidentally came into contact with phosgene, while carrying out the maintenance work. As he inhaled a large number of toxic gases like phosgene, he died within 72 hours.  After that, journalist Rajkumar Keswani started an investigation and made a publication against UCIL in the local paper Rapat in the name of  "Wake up, people of Bhopal, you are on the edge of a volcano."

In January 1982,  24 workers of UCIL got affected, when they were exposed to the leakage of phosgene and they got admitted to the hospital. And the company said that none of the employees were wearing masks and so they were affected.  After the month, about 18 workers died due to the leakage of methyl isocyanate. In August 1982, one of the chemical engineers came in contact with liquid MIC and burned over 30% of his body. In 1983 and 1984, employees of the company faced many other leaks like MIC, chlorine, monomethyl amine, phosgene, and carbon tetrachloride.

Bhopal Gas Tragedy Case Study

The Bhopal UCIL has constructed three underground MIC storage tanks in the name of E610, E611, and E619. The total capacity of the tank is about 68000 litres.  Till December, the company continued its production and stored it in tanks.  According to the UCC safety regulation, no tanks should be filled with more than 50% of MIC. Because each tank will have pressure with inert nitrogen gas. To reduce the pressure, it is necessary to maintain the moisture content of the tank. 

In October 1984, the E610 tank lost its ability as it could not maintain the nitrogen gas pressure. So, the liquid MIC present inside the tank could not be pumped out. Due to this about 42 tons of MIC in E610 got wasted. After that, the Bhopal unit shut down the plant for maintenance. During late November, the company resumed the production of carbaryl using the stored MIC, which was leftover in the remaining two tanks. But the chemical in E610 was left unpumped as they could not re-established its pressure. Later, this became responsible for the occurrence of the Bhopal gas tragedy.  

Bhopal Gas Tragedy Causes

In early December 1984, Company started manufacturing many safety valves, which were already in poor condition. Also, to regulate pressure in the Tank E610, they introduced water, which increased the pressure and temperature of the tank to an uncontrollable level because of the exothermic reaction. Also, the reason behind the Bhopal gas leak is the presence of Methyl isocyanide in the iron container with the corroding non-stainless steel pipelines. Initially, the pressure of the tank was at  2 psi at 10:30 p.m and it reached 10 psi by 11 p.m. By 11.30 pm, workers in the MIC area felt minor exposure to the MIC gas leak. This problem went to the year of MIC supervisor at 11:45 pm and they planned to make a decision after 12.15 am, which is their tea break. 

Within five minutes after the tea break,  the tank E610 reached its critical state and started spreading at an alarming speed. The temperature of the tank reached a maximum scale which is above 25 °C (77 °F) and the pressure of the tank reached  40 psi (275.8 kPa). Within a few minutes, employees noticed cracks on the tank as the relief valve burst open. 

As the refrigeration system of the MIC tanks was shut down in January 1982, employees could not control the high temperature. The flare towers were already removed for maintenance, so the burnt MIC could not find a path to escape from the system.  Within 45 to 60 minutes, about 30 tonnes of MIC escaped from the tank to the atmosphere. And the toxic gas is blown in the southeastern direction of Bhopal. Employees of the UCIL and the residents around the UCIL were affected a lot due to the spread of methyl isocyanides. 

Effect of Bhopal Disaster 

The death rate of the Bhopal disaster was about 12000 to 15000. ICMR also kept secrets about the health of people till 1994. As per the record, about 520000 people were affected by the gas leaked in the Bhopal tragedy.  In the Bhopal gas leak tragedy, about 200000 people were below the age of 15 years and 3000 pregnant women were also affected. In 1991, the death toll announced by the officials was about 2,256. The government of Madhya Pradesh also confirmed the total death toll from the Bhopal gas tragedy case study is about 3,787. 

People who were explored to the Bhopal gas tragedy got long term health impacts like scars on the cornea, corneal opacities, Chronic conjunctivitis, and early cataracts, People also got respiratory problems like, aggravation of tuberculosis, pulmonary fibrosis, Obstructive and/or restrictive disease, and chronic bronchitis. Also, they faced problems in neurological systems like fine motor skills,  impairment of memory, numbness, etc.  Many affected people lost their reproduction capability,  chromosomal aberrations, cancer, immune deficiency and many other problems. Approximately, about 120,000 to 150,000 survivors were still facing serious health hazards because of the Bhopal disaster. 

Conclusion

This article gave you a complete Bhopal gas tragedy summary with the reason behind Bhopal disaster with its case study, causes and effect in detail. The key points that you need to remember:

• The Date of the Bhopal Gas Tragedy - Dec 3, 1984

• Company Name - Union Carbide India Limited

• Location - Bhopal, Madhya Pradesh, India

• Gas leaked - MIC ( Methyl Isocyanate )