In the 1969, Union Carbide set up a plant in Bhopal, India, to manufacture pesticides which were considered essential in the drive for agricultural self-sufficiency. The facility was part of India's "Green Revolution" and industrialization policy. Union Carbide facility produced and stored a particularly dangerous chemical, methyl isocyanate (MIC). The plant experienced six accidents between 1981 and 1984, at least three of which involved MIC or phosgene, a highly poisonous gas used in World War I and a component in the manufacture of pesticide. On December 3, 1984, the world witnessed the worst industrial catastrophe in history - often referred to as the Three Mile Island of the chemical industry. A result of technological, industrial, legal and human error, the incident took the lives of 8000 people immediately after the disaster, and injured about 400,000, with the toll still rising to this day.

The Causes

The immediate cause of the chemical reaction was the seepage of water (500 Litres) into the MIC storage tank. The results of this reaction were exacerbated by the failure of containment and safety measures and by a complete absence of community information and emergency procedures. The long term effects were made worse by the absence of systems to care for and compensate the victims. Furthermore, safety standards and maintenance procedures at the plant had been deteriorating and ignored for months. The following list gives a synopsis of the defects of the MIC unit:

Gauges measuring temperature and pressure in the various parts of the unit, including the crucial MIC storage tanks, were so
   unreliable that workers ignored early signs of trouble;

The refrigeration unit for keeping MIC at low temperatures (and therefore less likely to undergo overheating and expansion
   should a contaminant enter the tank) had been shut off for some time;

The gas scrubber, designed to neutralize any escaping MIC, had been shut off for maintenance. Even had it been operative,
   post-disaster inquiries revealed, the maximum pressure it could handle was only one-quarter that which was actually reached
   in the accident;

The flare tower, designed to burn off MIC escaping from the scrubber, was also turned off, waiting for replacement of a
  corroded piece of pipe. The tower, however, was inadequately designed for its task, as it was capable of handling only a
  quarter of the volume of gas released;

The water curtain, designed to neutralize any remaining gas, was too short to reach the top of the flare tower, from where the
   MIC was billowing;

The lack of effective warning systems; the alarm on the storage tank failed to signal the increase in temperature on the night of
   the disaster;

MIC storage tank number 610 was filled beyond recommended capacity;

A storage tank which was supposed to be held in reserve for excess MIC already contained the MIC;

The leak of toxic MIC reacted with a sizable volume of water that had made its way into the MIC storage tanks. Action by the staff and supervisors was too late to contain the leak, and forty tons of highly toxic MIC flowed out of the tanks over two hours. And even if they had reacted immediately, the safety standards accepted at the plant would not have allowed them to do anything about it. Thus the methyl isocyanate gas escaped into the air and drifted eight kilometers downwind over the city of Bhopal, population 900,000, poisoning almost all in its path.

The Impact

The most seriously affected areas were those nearest to the plant, the absolutely poorest sector of the population. Even now, 10-15 people are dying every month from exposure related diseases and their complications. Over 120,000 children, men and women continue to suffer acutely from a host of exposure related illnesses and their complications. Damage to the respiratory system has led to the prevalence of pulmonary tuberculosis which has been found to be more than three times the national average. In the years following the disaster, the stillbirth rate was three times, perinatal mortality was two times and neonatal mortality was one and a half times more than the comparative national figures. According to a study conducted by Mcgill University, Canada, 40% of the women pregnant at the time of the disaster aborted. Another study reported nearly five times increase in the rate of spontaneous abortion as a result of the Union Carbide Disaster..

The Following Events

The accident was a result of poor safety management practices, poor early warning systems, and the lack of community preparedness. Investigations have revealed that corporate negligence failed to bring about the much needed change in the malfunctioning safety equipments and improperly trained workers at the chemical plant. Immediately after the disaster, the Parliament enacted the Bhopal Gas Leak Disaster (Processing of claims) Act in 1985 to ensure that claims arising out of the disaster were dealt with speedily. Shortly after the Bhopal Act was passed, the Indian Government sued Union Carbide in the United States.

The Bhopal disaster raised complex legal, moral and ethical questions about liability of parent companies for their subsidiaries, of transnational companies engaged in hazardous activities, and of governments caught between attracting industry to invest in business development while being in harmony with environment. Union Carbide paid a sum of $470m in an out-of-court settlement with the Indian government in 1989. Dow Chemical, which bought Union Carbide in 2001, has refused to take responsibility for the company they bought or even clean up the waste that still lies at the site. Bhopal has been in a chronic crisis since the accident. Only the parameters of the crisis have changed with time. At the time of the accident, medical and ecological damages were most
salient; today, the economic and social damages are more important.

The Lessons Learnt from the Disaster

The Bhopal accident marked a watershed in twentieth-century industrial safety. Efforts to advance the understanding of corporate accountability received a new dimension after the Tragedy. Over the past 20 years, despite the lack of a definitive, rigorous assessment of chemical safety in most part of the world, strides have been made in culture, practices, and attitudes in the chemical-handling community, as well as in the regulatory environment that governs the industry. If Bhopal was a wake-up call, the call for ongoing improvement in chemical safety has been answered in certain ways by the industry and other stakeholders in some countries. Today various groups with diverse agendas are increasingly finding ways to work together in a spirit of cooperation to reduce or prevent accidents, and to enhance the protection of personnel and the public alike. Perhaps the most important development in those efforts has been the widespread adoption of a concept called process safety. Process safety is a comprehensive, systematic approach encompassing the proactive identification, evaluation, and mitigation or prevention of chemical releases that could occur as a result of failures in process, procedures, or equipment. Although the idea had been in existence before the Bhopal disaster, it was the tragedy that brought about its necessity as industry standard practice. Industry’s appreciation of the importance of safety and its impact on both the bottom line and the sector's public image surfaced after the disaster. Community’s right to know about the nature of the chemicals being handled in the nearby chemical manufacturing units, their preparedness for and their response to any chemical emergency are now been considered to be important aspects in the field of environmental risk management..