The Bhopal disaster, also referred to as the Bhopal gas tragedy, was a gas leak incident in India, considered the world’s worst industrial disaster.It occurred on the night of 2–3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate gas and other chemicals. The toxic substance made its way in and around the shantytowns located near the plant. Estimates vary on the death toll. The official immediate death toll was 2,259. The government of Madhya Pradesh confirmed a total of 3,787 deaths related to the gas release. Others estimate 8,000 died within two weeks and another 8,000 or more have since died from gas-related diseases. A government affidavit in 2006 stated the leak caused 558,125 injuries including 38,478 temporary partial injuries and approximately 3,900 severely and permanently disabling injuries.
UCIL was the Indian subsidiary of Union Carbide Corporation (UCC), with Indian Government controlled banks and the Indian public holding a 49.1 percent stake. In 1994, the Supreme Court of India allowed UCC to sell its 50.9 percent interest in UCIL to Eveready Industries India Limited. The Bhopal plant was later sold to McLeod Russel (India) Ltd. Dow Chemical Company purchased UCC in 2001.
Civil and criminal cases are pending in the District Court of Bhopal, India, involving UCC and Warren Anderson, UCC CEO at the time of the disaster. In June 2010, seven ex-employees, including the former UCIL chairman, were convicted in Bhopal of causing death by negligence and sentenced to two years imprisonment and a fine of about $2,000 each, the maximum punishment allowed by Indian law. An eighth former employee was also convicted, but died before the judgment was passed.
The pre-event phase
The UCIL factory was built in 1969 to produce the pesticide Sevin (UCC’s brand name for carbaryl) using methyl isocyanate (MIC) as an intermediate. A MIC production plant was added in 1979. After the Bhopal plant was built, other manufacturers including Bayer produced carbaryl without MIC, though at a greater manufacturing cost. However, Bayer also uses the UCC process at the chemical plant once owned by UCC at Institute, West Virginia, USA.
The chemical process employed in the Bhopal plant had methylamine reacting with phosgene to form MIC, which was then reacted with 1-naphthol to form the final product, carbaryl. This “route” differed from the MIC-free routes used elsewhere, in which the same raw materials were combined in a different manufacturing order, with phosgene first reacting with naphthol to form a chloroformate ester, which was then reacted with methylamine. In the early 1980s, the demand for pesticides had fallen, but production continued, leading to buildup of stores of unused MIC.
In 1976, two trade unions complained of pollution within the plant. In 1981, a worker was splashed with phosgene. In a panic, he removed his mask, inhaling a large amount of phosgene gas which resulted in his death 72 hours later. UCC was warned by American experts who visited the plant after 1981 of the potential of a “runaway reaction” in the MIC storage tank. Local Indian authorities had warned the company of the problem as early as 1979, but constructive actions were not undertaken by UCIC at that time. In January 1982, a phosgene leak exposed 24 workers, all of whom were admitted to a hospital. None of the workers had been ordered to wear protective masks. One month later, in February 1982, a MIC leak affected 18 workers. In August 1982, a chemical engineer came into contact with liquid MIC, resulting in burns over 30 percent of his body. Later that same year, in October 1982, there was another MIC leak. In attempting to stop the leak, the MIC supervisor suffered intensive chemical burns and two other workers were severely exposed to the gases. During 1983 and 1984, there were leaks of MIC, chlorine, monomethylamine, phosgene, and carbon tetrachloride, sometimes in combination.
Factors leading to the magnitude of the gas leak mainly included problems such as; storing MIC in large tanks and filling beyond recommended levels, poor maintenance after the plant ceased MIC production at the end of 1984, failure of several safety systems due to poor maintenance, and safety systems being switched off to save money— including the MIC tank refrigeration system which could have mitigated the disaster severity. The situation was worsened by the mushrooming of slums in the vicinity of the plant, non-existent catastrophe plans, and shortcomings in health care and socio-economic rehabilitation.
Other factors identified by the inquiry included: use of a more dangerous pesticide manufacturing method, large-scale MIC storage, plant location close to a densely populated area, undersized safety devices, and the dependence on manual operations. Plant management deficiencies were also identified – lack of skilled operators, reduction of safety management, insufficient maintenance, and inadequate emergency action plans.
Attempts to reduce expenses affected the factory’s employees and their conditions. Kurzman argues that “cuts…meant less stringent quality control and thus looser safety rules. A pipe leaked? Don’t replace it, employees said they were told … MIC workers needed more training? They could do with less. Promotions were halted, seriously affecting employee morale and driving some of the most skilled … elsewhere”. Workers were forced to use English manuals, even though only a few had a grasp of the language.
By 1984, only six of the original twelve operators were still working with MIC and the number of supervisory personnel was also halved. No maintenance supervisor was placed on the night shift and instrument readings were taken every two hours, rather than the previous and required one-hour readings. Workers made complaints about the cuts through their union but were ignored. One employee was fired after going on a 15-day hunger strike. 70% of the plant’s employees were fined before the disaster for refusing to deviate from the proper safety regulations under pressure from the management.
In addition, some observers, such as those writing in the Trade Environmental Database (TED) Case Studies as part of the Mandala Project from American University, have pointed to “serious communication problems and management gaps between Union Carbide and its Indian operation”, characterised by “the parent companies [sic] hands-off approach to its overseas operation” and “cross-cultural barriers”.
Equipment and safety regulations
The MIC tank alarms had not been working for four years and there was only one manual back-up system, compared to a four-stage system used in the United States. The flare tower and several vent gas scrubbers had been out of service for five months before the disaster. Only one gas scrubber was operating: it could not treat such a large amount of MIC with sodium hydroxide (caustic soda), which would have brought the concentration down to a safe level. The flare tower could only handle a quarter of the gas that leaked in 1984, and moreover it was out of order at the time of the incident. To reduce energy costs, the refrigeration system was idle. The MIC was kept at 20 degrees Celsius, not the 4.5 degrees advised by the manual. Even the steam boiler, intended to clean the pipes, was inoperational for unknown reasons. Slip-blind plates that would have prevented water from pipes being cleaned from leaking into the MIC tanks, had the valves been faulty, were not installed and their installation had been omitted from the cleaning checklist. The water pressure was too weak to spray the escaping gases from the stack. They could not spray high enough to reduce the concentration of escaping gas. In addition to it, carbon steel valves were used at the factory, even though they were known to corrode when exposed to acid.
According to the operators, the MIC tank pressure gauge had been malfunctioning for roughly a week. Other tanks were used, rather than repairing the gauge. The build-up in temperature and pressure is believed to have affected the magnitude of the gas release. UCC admitted in their own investigation report that most of the safety systems were not functioning on the night of 3 December 1984. The design of the MIC plant, following government guidelines, was “Indianized” by UCIL engineers to maximise the use of indigenous materials and products. Mumbai-based Humphreys and Glasgow Consultants Pvt. Ltd., were the main consultants, Larsen & Toubro fabricated the MIC storage tanks, and Taylor of India Ltd. provided the instrumentation. In 1998, during civil action suits in India, it emerged that the plant was not prepared for problems. No action plans had been established to cope with incidents of this magnitude. This included not informing local authorities of the quantities or dangers of chemicals used and manufactured at Bhopal.
When the factory was closed in 1986, pipes, drums and tanks were sold. The MIC and the Sevin plants are still there, as are storages of different residues. Isolation material is falling down and spreading. The area around the plant was used as a dumping area for hazardous chemicals. In 1982 tubewells in the vicinity of the UCIL factory had to be abandoned and tests in 1989 performed by UCC’s laboratory revealed that soil and water samples collected from near the factory and inside the plant were toxic to fish. Several other studies had also shown polluted soil and groundwater in the area. Reported polluting compounds include 1-naphthol, naphthalene, Sevin, tarry residue, mercury, toxic organochlorines, volatile organochlorine compounds, chromium, copper, nickel, lead, hexachloroethane, hexachlorobutadiene, and the pesticide HCH.
In order to provide safe drinking water to the population around the UCIL factory, Government of Madhya Pradesh presented a scheme for improvement of water supply. In December 2008, the Madhya Pradesh High Court decided that the toxic waste should be incinerated at Ankleshwar in Gujarat, which was met by protests from activists all over India. On 8 June 2012, the Centre for incineration of toxic Bhopal waste agreed to pay 250 million (US$4.6 million) to dispose of UCIL chemical plants waste in Germany. On 9 August 2012, Supreme court directed the Union and Madhya Pradesh Governments to, take immediate steps for disposal of toxic waste lying around and inside the factory within six-month.
A US court rejected the law suit blaming UCC for causing soil and water pollution around the site of the plant and ruled that responsibility for remedial measures or related claims rested with the State Government and not with UCC. In 2005, the state government invited various Indian architects to enter their “concept for development of a memorial complex for Bhopal gas tragedy victims at the site of Union Carbide”. In 2011, a conference was held on the site, with participants from European universities which was aimed for the same. 
Occupational and habitation rehabilitation
33 of the 50 planned work-sheds for gas victims started. All except one was closed down by 1992. 1986, the MP government invested in the Special Industrial Area Bhopal. 152 of the planned 200 work-sheds were built and in 2000, 16 were partially functioning. It was estimated that 50,000 persons need alternative jobs, and that less than 100 gas victims had found regular employment under the government’s scheme. The government also planned 2486 flats in two- and four-story buildings in the “Widows colony” outside Bhopal. The water did not reach the upper floors and it was not possible to keep cattle which were their primary occupation. Infrastructure like buses, schools, etc. were missing for at least a decade.
Immediate relieves were decided two days after the tragedy. Relief measures commenced in 1985 when food was distributed for a short period along with ration cards. Madhya Pradeshgovernment’s finance department allocated 874 million (US$16 million) for victim relief in July 1985. Widow pension of 200 (US$3.70)/per month (later 750 (US$14)) were provided. They government also decided to pay 1500 (US$28) to families with monthly income 500 (US$9.20) or less. As a result of the interim relief, more children were able to attend school, more money was spent on treatment and food, and housing also eventually improved. From 1990 interim relief of 200 (US$3.70) was paid to everyone in the family who was born before the disaster.
The final compensation, including interim relief for personal injury was for the majority 25,000 (US$460). For death claim, the average sum paid out was 62,000 (US$1,100). Each claimant were to be categorised by a doctor. In court, the claimants were expected to prove “beyond reasonable doubt” that death or injury in each case was attributable to exposure. In 1992, 44 percent of the claimants still had to be medically examined.
By the end of October 2003, according to the Bhopal Gas Tragedy Relief and Rehabilitation Department, compensation had been awarded to 554,895 people for injuries received and 15,310 survivors of those killed. The average amount to families of the dead was $2,200.
In 2007, 1,029,517 cases were registered and decided. Number of awarded cases were 574,304 and number of rejected cases 455,213. Total compensation awarded was 15464.7 million (US$280 million).
On 24 June 2010, the Union Cabinet of the Government of India approved a 12650 million (US$230 million) aid package which would be funded by Indian taxpayers through the government.
Union Carbide’s defence
Now owned by Dow Chemical Company, Union Carbide denied the allegations against it on its website dedicated to the tragedy. The corporation claimed that the incident was the result of sabotage, stating that safety systems were in place and operative. It also stressed that it did all it could to alleviate human suffering following the disaster.