Issue Date: May 21, 2012
Promoting Safer Manufacturing
Chemical companies should always assess and, when possible, adopt inherently safer manufacturing processes that minimize or eliminate hazards, says a National Research Council (NRC) panel in a May 11 report. The committee says chemical manufacturers don’t 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 practices—such as minimizing use of or finding substitutes for toxic materials—that 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 committee’s chair and a chemistry professor at Georgia Institute of Technology.
The concept has been much discussed and is supported by chemical engineers, unions, community 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 that opportunities to lower risk and 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 work group to develop this framework.
Congress mandated the NRC study in 2009, during CSB’s 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 Bayer’s 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 aboveground 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 the examination to include a study of applying inherently safer process analysis at chemical plants.
“Bayer implicitly considered inherently safer designs,” Reichmanis notes, “but not explicitly.” As a result, she says, Bayer’s examination was too narrow. For instance, she notes, Bayer did not give adequate weight to the community’s role in promoting process safety, which has proven valuable to communities around chemical plants 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 has not yet reviewed the report and is withholding comment.
Responding to the report, two chemical industry trade associations—the American Chemistry Council and the Society of Chemical Manufacturers & Affiliates—stress their support for inherently safer process analysis. However, ACC recommends that the Center for Chemical Process Safety, a chemical industry group, rather than CSB lead the work group. SOCMA warns against shifting risk because of process changes and urges CSB to allow industry and other organizations to join the work group.
NRC plans to hold a community meeting about the report near the Bayer plant in Charleston, but no date has been set.
- Chemical & Engineering News
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