The BHOPAL GAS TRAGEDY:
The UCIL factory was established in 1969 near Bhopal. 50.9% was owned by Union Carbide Corporation (UCC) and 49.1 % by various Indian investors, including public sector financial institutions produced the pesticide carbaryl (trademark Sevin). In 1979 a methyl isocyanate (MIC) production plant was added to the site. MIC, an intermediate in carbaryl manufacture, was used instead of less hazardous but more expensive materials. UCC understood the properties of MIC and its handling requirements.[12][13][14]
During the night of December 2–3, 1984, large amounts of water entered tank 610, containing 42 tonnes of methyl isocyanate. The resulting exothermic reaction increased the temperature inside the tank to over 200 °C (392 °F), raising the pressure to a level the tank was not designed to withstand. This forced the emergency venting of pressure from the MIC holding tank, releasing a large volume of toxic gases into the atmosphere. The gases flooded the city of Bhopal, causing great panic as people woke up with a burning sensation in their lungs. Thousands died immediately from the effects of the gas and many were trampled in the panic.
Theories of how the water entered the tank differ. At the time, workers were cleaning out pipes with water, and some claim that owing to bad maintenance and leaking valves, it was possible for the water to leak into tank 610.[15] In December 1985 The New York Times reported that according to UCIL plant managers the hypothesis of this route of entry of water was tested in the presence of the Central Bureau Investigators and was found to be negative.[16] UCC also maintains that this route was not possible, and that it was an act of sabotage by a "disgruntled worker" who introduced water directly into the tank.[17] However, the company's investigation team found no evidence of the necessary connection.[18] The Trade Union Report failed to mention that the investigation was totally controlled by the government investigators denying UCC investigators any access to inspecting the ill-fated tank.
The 1985 reports[18][19][20] give a picture of what led to the disaster and how it developed, although they differ in details.
Factors leading to the gas leak include:
- The use of hazardous chemicals (MIC) instead of less dangerous ones
- Storing these chemicals in large tanks instead of over 200 steel drums.
- Possible corroding material in pipelines
- Poor maintenance after the plant ceased production in the early 1980s
- Failure of several safety systems (due to poor maintenance and regulations).
- Safety systems being switched off to save money—including the MIC tank refrigeration system which alone would have prevented the disaster.
The problem was made worse by the plant's location near a densely populated area, non-existent catastrophe plans and shortcomings in health care and socio-economic rehabilitation. Analysis shows that the parties responsible for the magnitude of the disaster are the two owners, Union Carbide Corporation and the Government of India, and to some extent, the Government of Madhya Pradesh.[3][4][21]
[edit] Public information
Much speculation arose in the aftermath. The closing of the plant to outsiders (including UCC) by the Indian government, and the failure to make data public contributed to the confusion. The CSIR report[20] was formally released 15 years after the disaster. The authors of the ICMR studies[22] on health effects were forbidden to publish their data until after 1994. UCC has still not released their research about the disaster or the effects of the gas on human health. Soon after the disaster UCC was not allowed to take part in the investigation by the government. The initial investigation was conducted entirely by the government agencies - Council of Scientific and Industrial Research (CSIR) under the directorship of Dr. Varadarajan and Central Bureau of Investigation (CBI).
UCC and the Government of India maintained until 1994, when the International Medical Commission on Bhopal met, that MIC had no longterm health effects.[4]
[edit] Contributing factors
- The deficiencies in the Bhopal plant design can be summarised as: choosing a dangerous method of manufacturing pesticides; large-scale storage of MIC before processing; location close to a densely populated area; under-dimensioning of the safety features; dependence on manual operations.[4]
- Deficiencies in the management of UCIL can be summarised: lack of skilled operators due to the staffing policy; reduction of safety management due to reducing the staff; insufficient maintenance of the plant; lack of emergency response plans.[4][23]
[edit] Plant production process
Union Carbide produced the pesticide Sevin (a trademarked brand name for carbaryl) using MIC as an intermediate. Until 1979, MIC was imported from the USA.[4] Other manufacturers, such as Bayer, made carbaryl without MIC, though at greater manufacturing costs.[24]
The chemical process, or "route", used in the Bhopal plant reacted methylamine with phosgene to form MIC (methyl isocyanate), which was then reacted with 1-naphthol to form the final product, carbaryl. This route differed from MIC-free routes used elsewhere, in which the same raw materials are combined in a different manufacturing order, with phosgene first reacted with the naphthol to form a chloroformate ester, which is then reacted with methyl amine. In the early 1980s, the demand for pesticides had fallen though production continued, leading to buildup of stores of unused MIC.[4][24]
[edit] Work conditions
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".[25]
- Workers were forced to use English manuals, even though only a few had a grasp of the language.[15][26]
- By 1984, only six of the original twelve operators were still working with MIC and the number of supervisory personnel was also cut in half. 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.[15][25]
- 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 management.[15][25]
- 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".[27]
- The personnel management policy led to an exodus of skilled personnel to better and safer jobs.[15][23]
[edit] Equipment and safety regulations
- It emerged in 1998, during civil action suits in India, that, unlike Union Carbide plants in the USA, its Indian subsidiary plants were 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.[3][4][15][24]
- The MIC tank alarms had not worked for 4 years.[3][4][15][28]
- There was only one manual back-up system, compared to a four-stage system used in the USA.[3][4][15][28]
- The flare tower and the vent gas scrubber had been out of service for 5 months before the disaster. The gas scrubber therefore did not treat escaping gases with sodium hydroxide (caustic soda), which might have brought the concentration down to a safe level.[28] Even if the scrubber had been working, according to Weir, investigations in the aftermath of the disaster discovered that the maximum pressure it could handle was only one-quarter of that which was present in the accident. Furthermore, the flare tower itself was improperly designed and could only hold one-quarter of the volume of gas that was leaked in 1984.[3][4][15][29]
- To reduce energy costs, the refrigeration system, designed to inhibit the volatilization of MIC, had been left idle—the MIC was kept at 20 degrees Celsius (room temperature), not the 4.5 degrees advised by the manual, and some of the coolant was being used elsewhere.[3][4][15][28]
- The steam boiler, intended to clean the pipes, was out of action for unknown reasons.[3][4][15][28]
- Slip-blind plates that would have prevented water from pipes being cleaned from leaking into the MIC tanks through faulty valves were not installed. Their installation had been omitted from the cleaning checklist.[3][4][15]
- Water sprays designed to "knock down" gas leaks were poorly designed—set to 13 metres and below, they could not spray high enough to reduce the concentration of escaping gas.[3][4][15][28]
- The MIC tank had been malfunctioning for roughly a week. Other tanks had been used for that week, rather than repairing the broken one, which was left to "stew". The build-up in temperature and pressure is believed to have affected the magnitude of the gas release.[3][4][15][28]
- Carbon steel valves were used at the factory, even though they corrode when exposed to acid.[24] On the night of the disaster, a leaking carbon steel valve was found, allowing water to enter the MIC tanks. The pipe was not repaired because it was believed it would take too much time and be too expensive.[3][4][15][28]
- UCC admitted in their own investigation report that most of the safety systems were not functioning on the night of December 3, 1984.[19]
- Themistocles D'Silva asserts in the latest book—The Black Box of Bhopal—that the design of the MIC plant, following government guidelines, was "Indianized" by UCIL engineers to maximize the use of indigenous materials and products. It also dispensed with the use of sophisticated instrumentation as not appropriate for the Indian plant. Because of the unavailability of electronic parts in India, the Indian engineers preferred pneumatic instrumentation. This is supported with original government documents, which are appended. The book also discredits the unproven allegations in the CSIR Report.[30]
[edit] Previous warnings and accidents
A series of prior warnings and MIC-related accidents had occurred:
- In 1976, the two trade unions reacted because of pollution within the plant.[4][23]
- In 1981, a worker was splashed with phosgene. In panic he ripped off his mask, thus inhaling a large amount of phosgene gas; he died 72 hours later.[4][23]
- In January 1982, there was a phosgene leak, when 24 workers were exposed and had to be admitted to hospital. None of the workers had been ordered to wear protective masks.
- In February 1982, an MIC leak affected 18 workers.[4][23]
- In August 1982, a chemical engineer came into contact with liquid MIC, resulting in burns over 30 percent of his body.[4][23]
- In October 1982, there was a leak of MIC, methylcarbaryl chloride, chloroform and hydrochloric acid. In attempting to stop the leak, the MIC supervisor suffered intensive chemical burns and two other workers were severely exposed to the gases.[4][23]
- During 1983 and 1984, leaks of the following substances regularly took place in the MIC plant: MIC, chlorine, monomethylamine, phosgene, and carbon tetrachloride, sometimes in combination.[4][23]
- Reports issued months before the incident by scientists within the Union Carbide corporation warned of the possibility of an accident almost identical to that which occurred in Bhopal. The reports were ignored and never reached senior staff.[4][24]
- Union Carbide 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 warned the company of problems on several occasions from 1979 onwards. Again, these warnings were not heeded.[4][24]
[edit] The leakage
- In November 1984, most of the safety systems were not functioning. Many valves and lines were in poor condition. Tank 610 contained 42 tonnes MIC, much more than safety rules allowed.[4]
- During the nights of 2–3 December, a large amount of water entered tank 610. A runaway reaction started, which was accelerated by contaminants, high temperatures and other factors. The reaction generated a major increase in the temperature inside the tank to over 200°C (400°F). This forced the emergency venting of pressure from the MIC holding tank, releasing a large volume of toxic gases. The reaction was sped up by the presence of iron from corroding non-stainless steel pipelines.[4]
- It is known that workers cleaned pipelines with water. They were not told by the supervisor to add a slip-blind water isolation plate. Because of this, and of the bad maintenance, the workers consider it possible for water to have accidentally entered the MIC tank.[4][15]
- UCC maintains that a "disgruntled worker" deliberately connected a hose to a pressure gauge.[4][17]
- UCC's investigation team found no evidence of the suggested connection.[18]
[edit] Timeline, summary
At the plant[4]
- 21.00 Water cleaning of pipes starts.
- 22.00 Water enters tank 610, reaction starts.
- 22.30 Gases are emitted from the vent gas scrubber tower.
- 00.30 The large siren sounds and is turned off.
- 00.50 The siren is heard within the plant area. The workers escape.
Outside[4]
- 22.30 First sensations due to the gases are felt—suffocation, cough, burning eyes and vomiting.
- 1.00 Police are alerted. Residents of the area evacuate. Union Carbide director denies any leak.
- 2.00 The first people reached Hamidia hospital. Symptoms include visual impairment and blindness, respiratory difficulties, frothing at the mouth, and vomiting.
- 2.10 The alarm is heard outside the plant.
- 4.00 The gases are brought under control.
- 6.00 A police loudspeaker broadcasts: "Everything is normal".
[edit] Health effects
[edit] Short term health effects
- The gas cloud composed mainly of materials denser than the surrounding air, stayed close to the ground and spread outwards through the surrounding community. The initial effects of exposure were coughing, vomiting, severe eye irritation and a feeling of suffocation. People awakened by these symptoms fled away from the plant. Those who ran inhaled more than those who had a vehicle to ride. Owing to their height, children and other people of shorter stature inhaled higher concentrations. Many people were trampled trying to escape.[4]
- Thousands of people had succumbed by the morning hours. There were mass funerals and mass cremations as well as disposal of bodies in the Narmada river. 170,000 people were treated at hospitals and temporary dispensaries. 2,000 buffalo, goats, and other animals were collected and buried. Within a few days, leaves on trees yellowed and fell off. Supplies, including food, became scarce owing to suppliers' safety fears. Fishing was prohibited as well, which caused further supply shortages.[4]
- A total of 36 wards were marked by the authorities as being "gas affected", affecting a population of 520,000. Of these, 200,000 were below 15 years of age, and 3,000 were pregnant women. In 1991, 3,928 deaths had been certified. Independent organizations recorded 8,000 dead in the first days. Other estimations vary between 10,000 and 30,000. Another 100,000 to 200,000 people are estimated to have permanent injuries of different degrees.[4]
[edit] Hydrogen cyanide or not?
- Whether hydrogen cyanide was present in the gas mixture is still a controversy.[31][32]
- Exposed at higher temperatures, MIC breaks down to hydrogen cyanide (HCN). According to Kulling & Lorin, at +200°C, 3 % of the gas is HCN.[33] However, according to another scientific publication,[34] MIC when heated in the gas-phase starts breaks down to hydrogen cyanide (HCN) and other products above 400°C. Concentrations of 300 ppm can lead to immediate collapse.
- Laboratory replication studies by CSIR and UCC scientists failed to detect any HCN or HCN- derived side products. Chemically, HCN is known to be very reactive with MIC.[35] HCN is also known to react with hydrochloric acid, ammonia, and methylamine (also produced in tank 610 during the vigorous reaction with water and choloroform) and also with itself under acidic conditions to form trimers of HCN called triazenes. None of the HCN-derived side products were detected in the tank residue.[36]
- The non-toxic antidote sodium thiosulfate (Na2S2O3) in intravenous injections increases the rate of conversion from cyanide to non-toxic thiocyanate. Treatment was suggested early, but because of confusion within the medical establishments, it was not used on larger scale until June 1985.[4]
[edit] Long term health effects
- It is estimated that 20,000 have died since the accident from gas-related diseases. Another 100,000 to 200,000 people are estimated to have permanent injuries.[4]
- The quality of the epidemiological and clinical research varies. Reported and studied symptoms are eye problems, respiratory difficulties, immune and neurological disorders, cardiac failure secondary to lung injury, female reproductive difficulties and birth defects among children born to affected women. Other symptoms and diseases are often ascribed to the gas exposure, but there is no good research supporting this.[4]
- There is a clinic established by a group of survivors and activists known as Sambhavna. Sambhavna is the only clinic that will treat anybody affected by the gas, or the subsequent water poisoning, and treats the condition with a combination of Western and traditional Indian medicines, and has performed extensive research.[37]
- Union Carbide as well as the Indian Government long denied permanent injuries by MIC and the other gases. In January, 1994, the International Medical Commission on Bhopal (IMCB) visited Bhopal to investigate the health status among the survivors as well as the health care system and the socio-economic rehabilitation.
- The reports from Indian Council of Medical Research[22] were not completely released until around 2003.
- For a review of the research on the health effects of the Bhopal disaster, see Dhara & Dhara (2002).[38]
[edit] Aftermath of the leakage
- Medical staff were unprepared for the thousands of casualties.[4]
- Doctors and hospitals were not informed of proper treatment methods for MIC gas inhalation. They were told to simply give cough medicine and eye drops to their patients.[4]
- The gases immediately caused visible damage to the trees. Within a few days, all the leaves fell off.[4]
- 2,000 bloated animal carcasses had to be disposed.[4]
- "Operation Faith": On December 16, the tanks 611 and 619 were emptied of the remaining MIC. This led to a second mass evacuation from Bhopal.[4]
- Complaints of a lack of information or misinformation were widespread. The Bhopal plant medical doctor did not have proper information about the properties of the gases. An Indian Government spokesman said that "Carbide is more interested in getting information from us than in helping our relief work."[4]
- As of 2008, UCC had not released information about the possible composition of the cloud.[4]
- Formal statements were issued that air, water, vegetation and foodstuffs were safe within the city. At the same time, people were informed that poultry was unaffected, but were warned not to consume fish.[4]
[edit] Compensation from Union Carbide
- The Government of India passed the Bhopal Gas Leak Disaster Act that gave the government rights to represent all victims in or outside India.[4]
- UCC offered US$ 350 million, the insurance sum.[4] The Government of India claimed US$ 3.3 billion from UCC.[4] In 1999, a settlement was reached under which UCC agreed to pay US$470 million (the insurance sum, plus interest) in a full and final settlement of its civil and criminal liability.[4]
- When UCC wanted to sell its shares in UCIL, it was directed by the Supreme Court to finance a 500-bed hospital for the medical care of the survivors. Bhopal Memorial Hospital and Research Centre (BMHRC) was inaugurated in 1998. It was obliged to give free care for survivors for eight years.[4]
