This paper is based on technical work performed in seeking better ways to deal with the economics of accidental chemical release prevention, protection, and mitigation. It is presented to illustrate a methodology. The accidental release of toxic chemicals has received increased attention since the Bhopal, India tragedy of December 1984 when air release of methyl isocyanate killed over 2,000 people. While this was a dramatic event of historical proportions, hazardous releases of a lesser scale occur frequently. The benefit of prevention measures can be expressed as a reduction in the probability or frequency of an accidental release. The cost can be estimated by standard engineering cost estimating techniques. A cost effectiveness can be determined for each hazard control measure if the benefits and costs are known. Cost effectiveness is simply a cost-to-benefit ratio. In this paper, the costs and benefits of example control measures for preventing accidental releases are examined for a simple system. The authors illustrate a technique which can be applied to more complex systems and might be used to better define cost effectiveness of various means of accidental release prevention.
This manual can be used to orient personnel involved in inspecting and otherwise evaluating potential toxic-chemical release hazards to the fundamentals of release hazard control for 13 of the specific chemicals chosen for evaluation under Section 305(b) of the Superfund Amendments and Reauthorization Act (SARA) of 1986. It also guides the user to other technical literature for additional information. Section 305(b) requires that the EPA conduct a review of emergency systems for monitoring, detecting, and preventing releases of extremely hazardous substances at representative domestic facilities that produce, use, or store extremely hazardous substances. The EPA must also prepare and present to Congress a report with recommendations for initiatives for the development of technologies and systems for monitoring, detecting, and preventing the accidental release of chemical substances, and for public alert systems that warn of imminent releases.
The report estimates total chlorofluorocarbon (CFC) emissions from the various rigid foam manufacturing processes and from the foam products themselves, and examines potential methods for reducing these emissions. Options studied include replacement of CFC-blown products with alternative products not requiring CFCs, replacement of ozone-depleting CFCs with other chemicals less likely to destroy stratospheric ozone, and recovery/recycle of CFCs released during manufacturing processes. In the production of rigid cellular foams, CFCs are used as physical blowing agents to reduce foam density and impart thermal insulating properties. Such rigid foams include polyurethane, polystyrene, polyethylene, polypropylene, polyvinyl chloride, and phenolic foams. Uses of these foams include building insulation, packaging materials, and single-service dinnerware. Depletion of stratospheric ozone through action of halocarbons, particularly CFCs, has been the subject of extensive study and wide debate. Although many uncertainties remain, current scientific evidence strongly suggests that anthropogenic CFCs could contribute to depletion of the stratospheric ozone layer as was first postulated in 1974.
This manual discusses reducing the risk associated with an accidental release of chlorine. It identifies some of the potential causes of accidental releases that apply to the processes that use chlorine. It also identifies examples of potential causes, as well as measures that may be taken to reduce the accidental release risk. Such measures include recommendations on: plant design practices; prevention, protection, and mitigation technologies; and operation and maintenance practices. It provides conceptual cost estimates of possible prevention, protection, and mitigation measures. Chlorine is a highly reactive and corrosive liquid that boils at room temperature. It has an IDLH (immediately dangerous to life and health) concentration of 25 ppm, which makes it a substantial acute toxic hazard. Accidental releases of toxic chemicals at Bhopal and Chernobyl have increased public awareness of toxic-release problems. As a result of other, perhaps less-dramatic incidents in the past, portions of the chemical industry were aware of this problem long before these events. These same portions of the industry have made advances in the area.
This manual summarizes technical information that will assist in identifying and (therefore) controlling ammonia-associated release hazards specific to the South Coast Air Quality Management District (SCAQMD), which has considered strategies for reducing the risk of a major accidental air release of toxic chemicals. The strategy includes monitoring the storage, handling, and use of certain chemicals and providing guidance to industry and communities. Ammonia gas has an immediately dangerous to life and health (IDLH) concentration of 500 ppm, which makes it an acute toxic hazard. To reduce the risk associated with an accidental release of ammonia, some of the potential causes of accidental releases that apply to processes using ammonia in the SCAQMD must be identified. Examples of such potential causes are identified, as are measures that may be taken to reduce the accidental risk. These measures include recommendations on: plant design practices; prevention, protection, and mitigation technologies; and operation and maintenance practices. Conceptual costs of possible prevention, protection, and mitigation measures are estimated.
This report, discussing sulfur trioxide (SO/sub 3/), is one of a series addressing the prevention of accidental releases of toxic chemicals. SO/sub 3/, a clear oily liquid or solid at typical ambient conditions, has an Immediately Dangerous to Life and Health (IDLH) concentration of 20 ppm, which makes it an acutely toxic hazard. Reducing the risk associated with an accidental release of SO/sub 3/ involves identifying some of the potential causes of accidental releases that apply to process facilities that manufacture or use the chemical. The manual identifies examples of potential causes and measures that may be taken to reduce the accidental release risk. Such measures include recommendations on plant design practices, prevention, protection, and mitigation technologies, and operation and maintenance practices. Conceptual cost estimates of example prevention, protection, and mitigation measures are provided.
The report discusses the control of accidental releases of hydrogen cyanide (HCN) to the atmosphere. HCN has an IDLH (immediately dangerous to life and health) concentration of 50 ppm, making it an acute toxic hazard. Reducing the risk associated with an accidental release of HCN involves identifying some of the potential causes of accidental releases that apply to the process facilities that use HCN. The manual identifies examples of potential causes and measures that may be taken to reduce the accidental release risk. Such measures include recommendations on: plant design practices; prevention, protection, and mitigation technologies; and operation and maintenance practices. Conceptual cost estimates of example prevention, protection, and mitigation measures are provided. The accidental release of a toxic chemical at Bhopal, India, in 1984 was a milestone in creating an increased public awareness of toxic release problems. As a result of other, perhaps less dramatic, incidents in the past, portions of the chemical industry were aware of this problem long before Bhopal.
The volume discusses prevention and protection measures for controlling accidental releases of air toxics. The probability of accidental releases depends on the extent to which deviations (in magnitude and duration) in the process can be tolerated before a loss of chemical containment. Developing a satisfactory control system and equipment capable of withstanding deviations requires adherence to sound process and physical-plant design principles and to appropriate procedures and management practices. A process can be controlled by manipulating flow, temperature, pressure, composition, and quantity. A control system can be improved by improving the quality, specifications, and maintenance of physical components, and by duplicating components where warranted. The probability of equipment failure (causing a release) can be reduced by considering various aspects of physical-plant design. Finally, protection system technologies (e.g., flares, scrubbers, and enclosures) offer a last line of defense against accidental toxic chemical releases.
The SASOL I coal-gasification plant is part of a highly-integrated industrial complex which produces liquid and solid hydrocarbons, petrochemicals, LPG, and medium-Btu gas by Lurgi gasification followed by gas cleanup and Fischer-Tropsch synthesis. Many of the process units used in this plant are also found in the designs of a number of first-generation coal-gasification plants proposed for this country. Some of these projects have had tests performed at SASOL in order to obtain stream-characterization data for process and control systems design. Unfortunately, much of this data is proprietary. This document provides publicly available information and data with an emphasis on environmental and health aspects. The presentation, which is the sixth in a series of documents, is arranged for comparison of the plant configurations of and EHandS data from other coal-gasification plants included in this study.
This report discusses the control of accidental releases of ammonia to the atmosphere. Ammonia has an IDLH (immediately dangerous to life and health) concentration of 500 ppm, making it an acute toxic hazard. Reducing the risk associated with an accidental release of ammonia involves identifying some of the potential causes of accidental releases that apply to process facilities that use ammonia. This manual identifies examples of potential causes and measures that may be taken to reduce the accidental-release risk. Such measures include recommendations on: plant design practices; prevention, protection, and mitigation technologies; and operation and maintenance practices. Conceptual cost estimates of example prevention, protection, and mitigation measures are provided. The accidental release of a toxic chemical at Bhopal, India, in 1984 was a milestone in creating increased public awareness of toxic release problems. As a result of other, perhaps less dramatic, incidents in the past, portions of the chemical industry were aware of the problem long before Bhopal.
