Accidents with chemicals

The chemical industry received a wake-up call for improved safety when 40 tons of methyl isocyanate escaped from a pesticide plant into a densely populated area of Bhopal, India on Dec. 3,1984. This resulted in 3500 deaths and 150,000 injuries.85 According to one reviewer86 the accident 

At the time of the accident, a refrigeration system, a temperature indicator, and a flare tower were not functioning.87 Curiously, the Maharashtra Development Council (in the state next to the one in which Bhopal is located) advertised in 1998 

There have been 17 chemical releases that have exceeded Bhopal in volume and toxicity. Fortunately, their locations and weather conditions prevented disasters such as Bhopal. In 1994, failure of a storage tank at Occidental Chemical allowed as much as 500 lb of chlorine to escape through a hole the size of a filing cabinet.89 Fortunately, air currents did not carry the cloud of chlorine over Delaware City, about a mile away, or New Castle, Delaware, a few miles to the north. (Chlorine was used as a war gas in World War I.) 

The explosion of the nuclear reactor at Chernobyl (spelling changed recently to Chornobyl) in the Ukraine on April 26, 1986 sent radioactive material as far away as Sweden.90 The current death toll is 45. There has been a huge increase in childhood thyroid cancer, with cases as far as 500 km away 91 (U. S. bomb tests have also increased the incidence of thyroid cancers in the western United States.92) There is a 30-km exclusion zone around the plant where no one is allowed to live. This was created by the evacuation of 135,000 people 93 The accident is said to have happened because of combination of the physical characteristics of the reactor, the design of the control rods, human error and management shortcomings in the design, and implementation of the safety experiment.  

The world s worst radioactive contamination (twice that of Chernobyl) is at Mayak in Russia. This has resulted from explosion of a radioactive waste storage unit on September 29, 1957 and deliberate dumping of liquid waste into the Techa River in 1949-1956 94 

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The gains for society of improved chemicals control may be substantial, though not easy to quantify in monetary terms. They include, for example, reduced costs for health care as a result of fewer accidents with chemicals, fewer acute health effects caused by poisonings, skin corrosion or bums, reduced risk for chronic effects such as allergies, cancer, etc. Furthermore, improved chemicals control will lead to a reduction of costs for remediation of environmental damage and of other costs following from emissions, e.g. water and soil pollution due to accidents or misuse of chemicals. 

An acute effect of a substance is the effect of a single contact of a substance. The toxic effect can be started by some substances immediately after exposure, but it is also possible that the toxic reaction appears several hours to some days later. Accidents with chemicals or poisoning by foods, for example fungi or fish, are typical... 

Unfortunately, accidents with chemicals are common, and the data in these tables is by no means comprehensive, intended, rather, to give a picture into the relative risks associated with different chemicals and industries. The National Response Center—the federal agency to which oil and chemical companies report oil and chemical spills estimates that each year there are more than 25,000 fires, spills, or explosions involving hazardous chemicals, with about 1000 of these events involving deaths, injuries, or evacuations (Figure 2.1). 

The mining facility consists of four major operations 1) mining, ore extraction and transportation, 2) ore processing - treatment with chemical solvents to remove minerals, 3) removing impurities and 4) utilities e.g., electricity, steam, water, air and natural gas provided by the facility s power plant and by off-site suppliers. Accidents in any of these operations can stop the whole process. 

A chemical company was considering a larger reactor to expand production. Because of industry reported accidents with this process, a HAZOP was performed that identified the potential for a violent reaction with deadly consequences. A QRA was conducted to better understand the risk of expansion and to determine additional safety needs. 

Fauske, H. K. and M. Epstein, 1988, Source Term Considerations in Connection with Chemical Accidents and Vapor Cloud Modeling, Proceedings of the International Conference on Vapor Cloud Modeling, CCSP, 251-273. 

One of the most frequent causes of accidents involving chemicals is linked to their high inflammability. Most organic products are inflammable. This chapter is concerned with these products but it is also relevant to some inflammable inorganic substances as well. 

The same chemicals are involved in accidents with ozone, the difference being that... 

Operating with chemicals and pressurized containers always carries a certain risk, but the safety features and the precise reaction control of the commercially available microwave reactors protect the users from accidents, perhaps more so than with any classical heating source. The use of domestic microwave ovens in conjunction with flammable organic solvents is hazardous and must be strictly avoided as these instruments are not designed to withstand the resulting conditions when performing chemical transformations. 

It is human nature to perceive the accident with the greater loss of life as the greater tragedy. The potential for large loss of life gives the perception that the chemical industry is unsafe. 

From Chapter 1 it appeared that all the existing safety management systems and tools cannot prevent accidents with hazardous substances in the chemical process industry. In this Chapter, the most commonly used safety indicators will be analysed to derive the set of deviations used for indicating. These deviations are then compared with deviations present in an accident trajectory prior to recent accidents. The differences between the two sets of deviations are then discussed to indicate why accidents still occur. These differences show shortcomings in current safety indicators and are used to set the criteria for a new safety indicator. 

In this Chapter further evidence is provided that precursors exist long before they escalate into an accident. It will be demonstrated that the existence of precursor information could have been used to foresee and even prevent recent accidents with hazardous substances. Moreover, a set of precursors retrieved from 17 recent accidents in the Dutch chemical process industry is used to validate the 7-stage protocol developed in the previous Chapter. In spite of the limited accident information it is shown that if a proper control action had been initiated, all of these 17 accidents could have been prevented. 

The Chemical Corps had already sustained a serious black eye after an accident with nerve gas near Dugway Proving Grounds in Utah. In 1968, a small plane had sprayed VX as part of a dissemination test. Unexpectedly, winds blew it in the wrong direction. Although there were no human casualties, many sheep grazing on nearby farms died. 

Eymard s khellin derivatives were dissolved in valproic acid and, following the practice of submitting all such compounds for evaluation in an antiepileptic screening model, they were studied for anticonvulsant activity. These preliminary studies revealed profound anticonvulsant activity. Shortly after this, Meunier serendipitously decided to use valproic acid as a solvent for an unrelated coumarin compound and, although chemically dissimilar to Eymard s khellins, this coumarin exhibited identical anticonvulsant properties. The fact that both compounds had been dissolved in the same solvent was realized immediately. The antiepileptic action of valproic acid was thus discovered completely by accident, with the first successful clinical trial occurring in 1963. 

Thomas Vaughan is said to have died from the fumes of the escaping mixture, and other laboratory accidents are reported. Such admonitions, coupled with our own experiences, have led us to be very careful in experimenting with chemicals, and at last to reject them altogether as worthless, and study more closely into nature. 

Human activities are associated with the use and disposal of a variety of chemicals and chemical products. This is the situation for a householder, a laboratory student, and also the industry worker. Many materials have properties that make them hazardous. They can create physical (fire, explosion) or health hazards (toxicity, chemical bums). However, there are many ways to work with chemicals which can both reduce the probability of an accident and reduce the consequences should an accident occur. Risk minimization depends on safe practices, appropriate engineering controls for chemical containment, the proper use of personnel protective equipment, use of the least amount of material necessary, and substitution of a less-hazardous chemical for a more hazardous one. Before beginning any chemical processing or operation, ask What would happen if. .. The answer to this question requires understanding of the hazards associated with chemicals, the equipment, and the procedure involved. The hazardous properties of the material and its intended use will dictate the precautions to be taken. 

The welfare of the people who work with chemical products and processes is at least as important as the welfare of the environment. Green chemistry is anthropocentric (as is sustainable development). Several green chemistry principles reflect this anthropocentrism. Principles 3 (less-hazardous chemical synthesis), 4 (design of safer chemicals), 5 (safer solvents and auxiliaries), and 12 (inherently safer chemistry for accident prevention) express concern for the health of the people who handle materials or attend to processes (Anastas and Warner, 1998). While many of these safety benefits also accrue to nonhuman organisms, the focus of the principles is on the people who are exposed to these materials and methods. Inasmuch as we cannot know all of the environmental needs of nonhuman things, it is hard to imagine how the focus could be on anything else. 

The IJ.S. Congress funded the board at 4 million for 1988. One key assumption, as stated in the Overview of the Chemical Safety Board s operations, is that there would be 330 catastrophic accidents annually. It was further assumed that within this total, between 10 and 15 of these accidents would be major catastrophic accidents with an average of two deaths per incident. [38] The industry must perform better than the predicted 330 catastrophic accidents for the public to fully earn our trust. 

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