Accidents Bhopal toxic chemical release

There are three types of TAP emissions continuous, intermittent, and accidental. Both routine emissions associated with a batch process or a continuous process that is operated only occasionally can be intermittent sources. A dramatic example of an accidental emission was the release of methyl isocyanate [624-83-9] in Bhopal, India. As a result of this accident, the U.S. Congress created Tide III, a free-standing statute included in the Superfund Amendments and Reauthorization Act (SARA) of 1986. Title III provides a mechanism by which the pubHc can be informed of the existence, quantities, and releases of toxic substances, and requires the states to develop plans to respond to accidental releases of these substances. Eurther, it requires anyone releasing specific toxic chemicals above a certain threshold amount to aimuaHy submit a toxic chemical release form to EPA. At present, there are 308 specific chemicals subject to Title III regulation (37). 

In 1988 producers of basic industrial chemicals, plastics, and fibers in tlie United States increased tlieir sales at least 10% to about 90 billion (exclusive of foreign subsidiaries) primarily as a result of increased demand at home and abroad. Along witli die increase of chemical production safety and accident prevendon liave become more critical and essential. Such dramadc releases of toxic chemicals as diose tliat occurred in Bhopal and at Three Mile Island have lieightened publie eoneem for die integrity of process facilities dial liandle liazardous materials. 

On December 3, 1984, a toxic gas release from a pesticide plant in India killed nearly 3000 people and injured at least 100,000 others. The chemical that leaked was methyl isocyanate, a chemical intermediate that was supposed to be stored in a cooled bunker near the plant s outer boundary. The vapor is highly toxic and causes cellular asphyxiation and rapid death. Despite engineering and procedural provisions to prevent its release, a total system breakdown resulted in the release of 40 tons of the deadly material into the densely populated community of Bhopal. Because of this incident, the plant was dismantled and ultimately the parent corporation. Union Carbide, was forced to make a number of organizational changes. The occurrence is considered by many to have been the most tragic chemical accident in history. 

On December 3 and 4, 1985, a chemical release causing a massive toxic gas cloud occurred at the Union Carbide India, Ltd, plant in Bhopal, India. (Union Carbide is now a part of The Dow Chemical Company.) The process involved used methyl isocyanate (MIC), an extremely toxic chemical, to make Sevin, a pesticide. According to various authoritative reports, about 1,700-2,700 (possibly more) people were killed, 50,000 people were affected seriously, and 1,000,000 people were affected in some way. The final settlement may involve billions of dollars. It was one of the worst industrial accidents in history. The accident occurred when about 120-240 gallons of water were allowed to contaminate an MIC storage tank. The MIC hydrolyzed, causing heat and pressure, which in turn caused the tank rupture disk to burst. 

In addition to the amounts of chemicals released to the environment through accidents, the U. S. Toxic Release Inventory shows the release of 2.43 billion lb into air, land, or water in 1996,169 down from 3.21 billion lb in 1992.170,171 (The data is available on a number of Internet sites, including www.epa.gov/opptintr/tri.) The total decline since the law became effective in 1987 has been 46%. This right-to-know law was enacted in the aftermath of the Bhopal accident. It now covers nearly 650 chemicals out of about... 

This accident has become widely known. It is an objective of many chemical process safety programs and government actions to avoid another Bhopal —that is, to avoid a severe release of toxic chemicals (usually referring to toxic chemicals in the air). Almost every chemical company in the world has been affected by this incident in one way or another, in the design and operation of chemical plants, in community action programs, and in the activities of such organizations as the American Institute of Chemical Engineers, the Chemical... 

The previous chapter described the consequences of a nuclear reactor accident. Chemical process accidents are more varied and do not usually have the energy to melt thick pressure vessels and concrete basemats. The consequences of a chemical process accident that releases a toxic plume, like Bhopal did, are calculated similarly to calculating the dose from inhalation from a radioactive plume but usually calculating chemical process accidents differ from nuclear accidents for which explosions do not occur. 

Materials that become more hazardous when contacted with water comprise another important class of incompatible materials. For example, carbonyl sulphide (COS) and calcium sulphide (CaS) both release toxic H2S on contact with water. Dry powders of sodium or potassium cyanide release toxic HCN in the presence of moisture. Care must be taken to prevent such materials from coming into contact with water during processing and storage. The 1985 Bhopal accident was started by a runaway reaction involving a water-sensitive chemical. 

Although toxic releases, in general, are not the principal cause of major accidents (relative to fire and explosion) associated with the chemical industry, they are a just cause of "considerable public apprehension" [1327a]. This concern has been compounded by an event which occurred in Bhopal, India in December 1984, in which over 2500 people were killed by a single toxic release of methyl isocyanate. 

Thus far, discussion has centered on chemical compounds with a military application. Other highly toxic industrial chemicals also pose a potential risk to the military. The disaster in Bhopal, India, in December 1984, when an estimated 8,000 persons died and another 30,000 were injured from breathing methylisocyanate and chlorine released in an industrial accident, is just one of many examples of the devastating effect of poisonous gases.26... 

The risk of toxic release accidents into the atmosphere or watercourses is very real, and there have been many examples. Four very notable and well-known examples - Seveso, Bhopal, Mississauga and the Sandoz chemical spill into the Rhine - are briefly outlined below, together with a more detailed description of a less well-known incident. 

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