According to a National Research Council (NRC) panel in a report released 10 May, chemical companies should always assess and, when possible, adopt inherently safer manufacturing processes that minimise or eliminate hazards. The committee says chemical manufacturers dont always consider inherently safer processes and many lack a clear, consistent corporate policy to conduct an adequate analysis. Inherently safer processes are a hierarchy of manufacturing practicessuch as minimising or finding substitutes for toxic materialsthat lower the threat of plant hazards or accidents, which affect workers and community residents. The goal is to eliminate hazards, dangerous materials, or processes, rather than to manage and control them, explains Elsa Reichmanis, the NRC committees chair and a chemistry professor at Georgia Institute of Technology. The concept has been much discussed and is supported by chemical engineers, unions, communities groups, and the chemical industry, but companies warn of difficulty in applying techniques of inherently safer processes. A decision-making tool is needed to provide companies with a means to consistently assess options, Reichmanis says. Such a tool, she adds, would also help ensure opportunities to lower risk as well as improve manufacturing are not missed and risks are not shifted among process alternatives. The committee, Reichmanis notes, urges the development of a framework to guide chemical plant managers when selecting among inherently safer alternatives and weighing the impact of these choices on safety, the environment, and product yield. The Chemical Safety & Hazard Investigation Board (CSB) or another entity, she says, should establish a workgroup to develop this framework. Congress mandated NRCs study in 2009, during CSBs investigation of a 2008 accident at the Bayer CropScience plant near Charleston, W.Va. Initially, the NRC study was intended to examine the feasibility of reducing or eliminating Bayers inventory of the highly toxic compound methyl isocyanate (MIC). Two workers died in the 2008 accident. The blast raised community concern because it endangered an above-ground storage tank holding 13,000 lb of MIC, the same chemical that caused the deaths of nearly 3,800 people in Bhopal India in 1984. In response, Bayer reduced on-site storage of MIC in August 2009. A year later, Bayer eliminated use of MIC at the plant. However, NRC continued its investigation, broadening it to also examine the application of inherently safer process analysis at chemical plants. Bayer implicitly considered inherently safer designs, Reichmanis notes, but not explicitly. As a result, she says, Bayers examination was too narrow. For instance, she notes, Bayer did not give adequate weight to the communitys role in process safety, which has proved valuable in communities in New Jersey and California. The report, says CSB Chairperson Rafael Moure Eraso, should serve as a model for Bayer and the chemical industry about how to assess and reduce toxic chemical hazards and build effective relationships with the surrounding community. Bayer says it had not yet reviewed the report and is withholding comment. Responding to the report, two chemical industry trade associationsthe American Chemistry Council and Society of Chemical Manufacturers & Affiliatesstress their support for inherently safer process analysis. However, ACC recommends that the Centre for Chemical Process Safety, a chemical industry group, rather than CSB lead the workgroup. SOCMA warns against risk shifting due to process changes and urges CSB to allow industry and other organisations to join the workgroup. NRC plans to hold a community meeting about the report near the Bayer plant in Charleston, W.Va., but no date has been set.
Chemical & Engineering News, 17 May 2012 ;http://pubs.acs.org/cen/news ;