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Technical Summary In 2008, an explosion and fire at a chemical production plant owned by Bayer CropScience (Bayer) in Institute, West Virginia resulted in the deaths of two employees and renewed attention to the onsite manufacture and storage of methyl isocyanate (MIC). MIC is a highly toxic inhalation hazard, and a large release of the chemical in Bhopal, India in 1984 resulted in the immediate deaths of over 3,000 people. In Institute, MIC was manufactured and stored onsite begin- ning in 1966 for use in the production of carbamate pesticides. These pesticides, including aldicarb (Temik) and carbaryl (Sevin), have been or are used for both agricultural and residential control of pest insects. Although no part of the MIC production or storage processes at the Institute facility played a role in the 2008 incident, the U.S. Chemical Safety and Hazard Investigation Board (CSB) found during its investigation that debris from the explosion hit the shield surrounding an aboveground storage container of MIC. The Board determined that, had the debris followed a different path, a relief valve vent pipe on the tank could have been damaged, which could have resulted in a release of MIC to the atmosphere. The investigation also highlighted a number of weaknesses in the Bayer facility’s emergency response systems and restart pro - cedures within the affected production unit. In light of these concerns, Congress directed the CSB to consult with the National Academy of Sciences for a study to examine the use and storage of MIC at the Bayer CropScience facility. The statement of task was finalized after a public comment period held by the CSB, and it can be found in Appendix A. In brief, the task was divided into three parts: (1) review current industry practice for the use and storage of MIC, including consideration of the key lessons of the Bhopal incident; (2) review current technologies for producing 13
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14 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE carbamate pesticides; and (3) examine the use and storage of MIC at the Bayer CropScience facility in Institute, West Virginia. The third part of the task was the most complex, containing the following subparts: 3.1.Identify possible approaches for eliminating or reducing the use of MIC in the Bayer carbamate pesticide manufacturing processes; 3.2.Estimate the projected costs of alternative approaches identified above; 3.3.Evaluate the projected benefits of alternative approaches identified above; 3.4.Compare this analysis to the inherently safer process assessments con - ducted by Bayer and previous owners of the Institute site; and 3.5.Comment, if possible, on whether and how inherently safer process (ISP) assessments can be utilized during post-incident investigations. STUDY CONTEXT Data gathering and report preparation were performed during a period of legal activity and community concern related to the facility and its production of MIC. When the study began in September 2010, the CSB investigation was not yet complete, and Bayer had begun efforts to reduce onsite inventory of MIC, and a new underground storage facility was being built for MIC in light of that reduction. In August 2010, Bayer announced that, because of the U.S. Environmental Protection Agency’s decision to cancel registration of aldicarb, the company would cease production of aldicarb by late 2014. This decision was followed up in January 2011 by a decision to shut down production of MIC by 2012 and cease production of aldicarb and two other pesticides, methomyl and carbaryl. At the time, Bayer intended to restart production of MIC in February 2011, after the plant modifications were complete, to continue production until the 2012 end date. However, also in February, a group of local residents filed suit against the company citing concerns about the restart process and MIC storage and manufacture onsite. This resulted in a court order to halt the restart process pending an evidentiary hearing, although preparations in anticipation of restart were allowed to continue. The court process continued through the month of February, and on March 18, stating that, “uncertainty over delays has led the com- pany to the conclusion that a restart of production can no longer be expected in time for the 2011 growing season”,1 Bayer announced that it no longer intended to restart production of MIC or aldicarb. In addressing the statement of task, the committee began by considering how to address Task 3 and determining the data-gathering required. In addressing Task 3, the committee quickly determined that a detailed, full analysis of all alter- 1 Bayer. 2011. Bayer CropScience Announces Decision Not to Resume MIC Production. Bayer Press Release: March 18, 2001 [online]. Available: www.bayercropscience.com/bcsweb/crop protection.nsf/id/84634C20BB57C2D3C125785700503244.
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15 TECHNICAL SUMMARY native chemistries available for the production of aldicarb and carbaryl, including their manufacturing and energy costs, would require significantly greater invest- ments than were available for the study. The investment required to fully analyze any one alternative is typically a multi-million dollar expenditure, and further, costs are highly dependent on the facility design, and accurate financial analysis requires specialized tools and information that is often unavailable to the public. In addition, in light of the de-registration of aldicarb and subsequent cessation of MIC, aldicarb, and carbaryl production at the Institute plant, the value of a full literature review for the chemical manufacturing community was reduced as the information available from such a review would have no longer have a potential use for the facility. With these limitations in mind, the committee chose to focus on a select set of possible alternative production processes for aldicarb and carbaryl. These chosen alternatives had been evaluated by Bayer and the facility’s legacy owners, and as a result, information about the chemistry and possible manufacturing processes were available for each. This approach reduced further the value that a literature review, which would be limited in its scope to information about manufacturing processes available in the open literature. As a result of these various factors, the committee chose to focus its efforts primarily on Task 3 and addressed Task 2 only in the context of the chosen alternative production processes. In this report, the selected alternatives and associated trade-offs are pre - sented, with particular attention to safety considerations. In addition, the context in which these trade-offs must be evaluated (financial, regulatory, etc.) is dis - cussed. Finally, because deciding between alternative processes requires con - sideration and weighing of a number of different factors, including safety, one possible framework for evaluating these complex decisions is presented. Within this summary, the committee’s findings, conclusions, and recommendation have been highlighted in bold text. They have also been aggregated in Box 6 at the end of the summary chapter. INHERENTLY SAFER PROCESS ASSESSMENTS AND PROCESS SAFETY MANAGEMENT Within the chemical engineering community, the use of process safety man - agement (PSM) systems is considered standard practice. PSM is a methodology composed of a number of different elements that, when evaluated as a whole, support organizational safety culture and practices. Although the “elements” or components of any given PSM system may vary somewhat between countries and organizations, the fundamental structures remain similar. Within the United States, Occupational Safety and Health Administration (OSHA) administers the Process Safety Management Standard, which has fourteen mandatory elements relating to, among other things, training, documentation, incident investigation, compliance audits, and process hazard analysis. Although companies are required
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16 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE to address those 14 elements, they are not limited to them. PSM is most effective at supporting a safe environment when it is contained within an overall organiza - tional structure that encourages a culture of safety among its employees. Within the element of process hazard analysis, employers are required to, “identify, evaluate, and control the hazards involved in the process” (29 CFR § 1910.119). To accomplish control of hazards, companies can consider a hierarchy of hazard control with the tiers of inherent, passive, active, and procedural con - trols. Only the inherent tier invites consideration of elimination or minimization of a given hazard; all other tiers are focused on control of an existing hazard. It is important to remember, however, that making a system inherently safer through, for example, substitution may result in a shift from one hazard or risk to another, and the full impact of any change on the overall hazard analysis should be considered as part of the decision-making process. The context in which an inherently safer process assessment is performed is important as this can affect the way that a given risk or hazard is weighted against another in the analysis. Although a valuable tool, consideration of ISPs is not a required component of OSHA’s PSM Standard. INHERENTLY SAFER PROCESS ASSESSMENTS AT BAYER CROPSCIENCE To address the task, a great deal of information was received from Bayer regarding the use and storage of MIC at the facility under their management and the management of the legacy companies, particularly Union Carbide and Rhône Poulenc. This information was examined in order to assess whether ISP assessment or its principles of substitute, minimize, moderate, and simplify were mentioned or evaluated within the analysis of different processes and synthetic routes. In addition, the role that ISP or its principles play in the PSM systems of Bayer and the legacy companies was evaluated. Although materials relating to the alternatives and their evaluation were provided to the committee for review in good faith, the documentation was rather disjointed and discontinuous, with doc - uments ranging from undated handwritten notes without attribution to in-depth type-written analyses of findings. The assessments presented here are drawn from these documents and from the academic and patent literature, and information gaps within the historic documents could result in gaps within these assessments. In the course of the study, Bayer presented the company’s approach to PSM, stating that ISP is an integral part of its PSM analysis. However, although claimed to be an integral PSM component, inherent safety considerations are incor- porated into Bayer’s PSM efforts in an implicit manner that is dependent on the knowledge base of the individual facilitating the particular activity (e.g., process hazard analysis or PHA). Although an implicit system of ISP incorpora- tion does not mean an absence of a commitment to inherent safety, it does mean that the commitment is not visible to the extent that might be considered desirable.
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17 TECHNICAL SUMMARY A risk of this implicit approach is that the ISP components and principles do not become part of corporate memory, and this can lead to missed opportunities for incorporation of ISPs and design into the production facility. Over the course of the study, the committee reviewed documentation describ- ing the history of the plant and alternative assessments performed by Bayer and the legacy owners of the facility. The committee finds Bayer and its prede- cessors did seek to reduce risks associated with MIC, and those efforts did incorporate some aspects of risk reduction associated with ISP principles. However, Bayer did not make statements or provide documentation indicat- ing that it had engaged in a systematic effort to incorporate ISP into the decision-making process. Several decisions regarding process safety were made over the years by the owners of the Institute plant. Most of these decisions involved adding additional safety protections to existing processes, rather than changes to the underlying process. Bayer and its predecessors evaluated trade-offs among the alterna - tives, but while analysis provides a very useful starting point for a compari- son of technologies, it excludes factors that may be important in the decision, from the perspective of both the company and the community. The committee concludes that Bayer CropScience did perform process safety assessments; however, Bayer and the legacy companies did not per- form systematic and complete ISP assessments on the process for manufac - turing MIC or the processes used to manufacture pesticides at the Institute site. Bayer and the previous owners performed hazard and safety assess- ments and made business decisions that resulted in MIC inventory reduction, elimination of aboveground MIC storage, and adoption of various passive, active, and procedural safety measures. However, these assessments did not incorporate in an explicit and structured manner, the principles of minimiza- tion, substitution, moderation, and simplification. The legacy owners identi - fied possible alternative methods that could have resulted in a reduction in MIC production and inventory, but determined that limitations of technol- ogy, product purity, cost, and other issues prohibited their implementation. INHERENTLY SAFER PROCESS ASSESSMENTS Within the statement of task, the NRC was specifically asked to compare its analysis of alternative approaches for eliminating or reducing MIC “to the inher- ently safer process assessments conducted by Bayer and previous owners of the Institute site.” This required consideration of the industry’s current understanding of ISPs and assessments as well as the approaches used by Bayer and the legacy companies. Drawing upon the expertise within the committee membership as well as that of the publications from the Center for Chemical Process Safety, the Department of Homeland Security, and other material available in the literature, the following findings, conclusions, and recommendation were developed.
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18 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE Inherently safer process assessments can be a valuable component of process safety management. However, the view of what constitutes an ISP varies among professionals, so the chemical industry lacks a common under- standing and set of practice protocols for identifying safer processes. Experts in ISP agree on the components that define ISP, but that understanding has not yet become common among the rest of the professional community. Although the general concept of ISP has made it into the community, the specifics are not well known outside of the expert group. One particular barrier for use of ISP assess - ments that has been noted by expert chemical engineers is a lack of effective methods for analyzing risk-based trade-offs. ISP assessments can be challenging because of the interconnected nature of chemical manufacturing processes, e.g., care must, taken that a risk reduction in one process element does not result in an unexpected risk transfer to a different element. One possible approach for addressing this issue is the use of multi-attribute or -criteria decision analysis, which is described briefly in the next section. Note that ISP analysis has the potential to reduce the impact of incidents by addressing some common concerns in emergency preparedness and response. In many cases, for example, emergency response units will spend the majority of their training on appropriate response to the most common incident rather than the most catastrophic incident. This is not unexpected in light of funding con - straints and the difficulties posed in coordinating the multitier, multiorganization response required for training for large-scale incidents or releases. However, it is just these large-scale incidents that pose the greatest risk to emergency respond - ers. Consistent application of ISP strategies by a company has the potential to decrease the required scope of organizational emergency preparedness programs by reducing the size of the vulnerable zones around its facilities. Such reductions are achieved by reducing the toxicity of the chemicals being used or produced, the quantity of the chemicals being stored, and the condi - tions under which they are being stored. PRODUCTION OF MIC AND CARBAMATE PESTICIDES: ALTERNATIVES ASSESSMENT Four possible categories of alternatives for the manufacture of carbamate pesticides were considered: (1) continuing with the existing process, (2) adopt - ing an alternative chemical process not involving MIC, (3) using an alternative process for MIC production that would consume MIC immediately and thus not require storage, and (4) reducing the volume of stored MIC and the risks of transporting MIC from one facility within the site to another by rearrang - ing process equipment. Note that the task was not to determine the best course of action but to consider and compare these alternatives and the trade-offs posed by each option with respect to costs and benefits to the company and community.
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19 TECHNICAL SUMMARY Each possible approach presents its own costs and benefits. For example, a non-MIC-based process for production of aldicarb means that there is no risk of worker exposure to MIC. However, that same non-MIC-based process could result in lower purity of the final material, which could result in greater risk of worker exposure to hazardous dust. Just-in-time production of MIC through a gaseous product would eliminate the risk of catastrophic release of that material within the community, but it would require a significant redesign of the facility and would, in its current form, result in a final product with lower purity than the existing process. In evaluating all of the alternatives, it became clear that no one method outperformed all others in every category of cost and benefit. The above paragraph highlights some of the technical costs and benefits, but when evaluating alternative approaches, nontechnical considerations should also be considered. One example of this is the perception of the choice by the sur- rounding community. The facility in Institute, West Virginia, as is true for many chemical manufacturing facilities, exists in close proximity to the surrounding community. In such situations, it is important to recognize the influence that local communities can have on corporate decision making, whether welcomed by the company or not. For example, the suit filed by some members of the local com - munity against Bayer played a role in the company’s decision to cease MIC and aldicarb production before the anticipated 2012 stop date. This is an example of how the perception of risk posed by the facility by the members of a surrounding community can affect whether a material or process is readily accepted, and the nature of the relationship between the community and the company may influence that risk perception. At a basic level, a neutral or positive relationship between a facility and its community allows for open discussion about risks and responses. It allows for a sense of trust that the experts on site are operating with care and consideration. A negative relationship can influence the community perception of risk, lead to distrust, and create an environment of defensiveness and lack of engagement on important issues relevant to everyone involved. The process ultimately chosen for the Institute site by the facility’s owners, although posing higher risks to the surrounding community due to the volume of MIC stored, decreases the amount of wastewater produced as compared with other methods and thus decreases potential damage to local surface waters. Deciding between multiple process alternatives with conflicting trade-offs is a concern faced by any company. It is clear that the development of a method that companies could use to weigh all of the trade-offs involved when consider- ing process choice from an inherently safer design perspective would be a useful tool for evaluating these concerns. A potential concern with using ISP analy- sis is that it may become focused too narrowly, and as a consequence, may overlook certain outcomes. Even when multiple outcomes are recognized, they may be inappropriately weighted. Both of these problems can result in a choice that does not reflect the optimal conclusion or the decision makers’ preferences.
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20 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE To assist the chemistry community in addressing the last of these findings, which as mentioned above has been noted as a barrier to performing inherently safer process assessments, the committee highlighted a method of decision analy- sis, multi-attribute utility (MAU) theory. This method was considered as an option for addressing appropriate weightings of multiple outcomes of an ISP analysis or assessment and to assist with placement of the findings of that analysis within the context of a full analysis of all costs and benefits associated with a process. MAU theory provides one possible framework for incorporating input and relative weightings from multiple perspectives and stakeholders, and as such, could be an aid for decision making. As a result, the committee recommends that the U.S. Chemical Safety Board and Hazard Investigation Board or other appropri- ate entity convene a working group to chart a plan for incorporating decision theory frameworks into ISP assessments. The working group should include experts in chemical engineering, ISP design, decision sciences, negotiations, and other relevant disciplines. The working group should identify obstacles to employing methods from the decision sciences in process safety assess - ments. It should identify options for tailoring these methods to the chemical process industry and incentives that would encourage their use. INCIDENT INVESTIGATION AND EMERGENCY RESPONSE In examining the potential utility of ISP assessments to incident investiga - tion, it becomes clear that the principles of ISP assessment can be used to good effect in conducting an incident investigation when the objective is the pre - vention of potential incidents having similar fundamental, underlying (root) causes. It is possible that over time, findings from ISP assessments performed in the wake of an accident could identify trends in process design that could be used to improve future systems. Findings from an investigation may be of use when refining the models that support existing ISP assessments. A post-incident ISP assessment may help identify unanticipated hazards within a given process that could inform the rebuild or redesign of the facility.