Web Date: February 1, 2011
Inherently Safer Design
The National Research Council will soon begin to explore the application of inherently safer chemical manufacturing processes, a study requested and funded by Congress last year. The first public meeting takes place Feb. 9 and 10 in Washington, D.C., with a report expected in September.
The concept of inherently safer chemical manufacturing was first developed and popularized by Trevor Kletz, a U.K. chemical engineer and author. Kletz described a goal of minimizing use and storage of toxic, flammable, or explosive chemicals in manufacturing through a host of means, such as substitution and process modifications. The end result is to eliminate or at least minimize an accident's impact if one occurred.
Its use has been controversial with some companies, which say it's too complicated, it's not cost effective, or it leads to other manufacturing problems. On the other hand, community groups and many chemical engineering professional organizations have pushed for its use.
NRC's study will closely examine an actual plant—the Bayer CropScience pesticide manufacturing facility in Institute, W.Va.—explains Dorothy Zolandz, director of the National Academies Board on Chemical Sciences & Technology, which is directing the study.
Members of the House of Representatives set aside $600,000 for the study after a fire and explosion at the Bayer facility in August 2008. The accident killed two workers and came close to blasting debris into an above-ground tank storing some 13,000 lbs of methyl isocyanate (MIC), the chemical responsible for the 1984 Bhopal, India, plant explosion that killed and injured thousands.
Since the Bhopal disaster, residents living near the West Virginia plant have urged Bayer and earlier owners to phase out MIC, which is an intermediate in the production of several pesticides. The Institute plant is the only U.S. facility and, worldwide, the only Bayer plant that uses MIC in production. Two weeks ago and a few days before the Chemical Safety & Hazard Investigation Board (CSB) released a report of its investigation of the 2008 accident, Bayer announced it would phase out MIC use over the next 18 months (C&EN, Jan. 24, page 7).
But NRC will go forward with its study and has selected 10 panel members, who have backgrounds in chemical engineering and production, chemical reactions, dispute resolution, occupational and environmental health, economics, and risk assessment. The panel's makeup is broad, Zolandz says. "Our study will examine more than pipes and engineering," she explains. "It also will look at the bigger picture—feasibility, cost-benefit implications, and community concerns."
The context of the study has changed slightly, Zolandz adds. "Now rather than being a report that might impact the future of Bayer, it is a report and a case study that will illuminate the use of inherently safer process assessments."
Because Bayer has already agreed to phase out MIC use, Zolandz says, some of the pressures that would have surrounded the fate of a particular plant have been removed. "In an odd way, it makes the study better," she says. "Here we have an actual on-the-ground plant that can we use to enlighten us about how these assessments are carried out, what their capabilities and limitations are, and so forth. We have a real case study.
"You can't just talk about inherent safer process assessments and have it make any sense when it is just pie in the sky," she adds.
This is not a subject that "goes away for CSB" just because the questions of Bayer's MIC use has been resolved, notes Daniel Horowitz, the board's managing director.
"Our interest has always been how inherent safer designs can benefit industry as they strive to make processes safer," Horowitz says. "Using Bayer as an example will help inform other decisions the board makes."
Although the majority of CSB's work, he says, focuses on safety management systems, on occasion the board recommends that a company pursue a safer technology or phase out use of a specific chemical, for instance, chlorine use in industrial water treatment.
"We are hoping for advice from the academy on how we as an agency should look at these inherently safer technological issues in our accident investigations," Horowitz adds.
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