Chemical plant blast: Inherent safety
What went wrong: A new safety video is out that looks at inherent safety which is the result of the Aug. 28, 2008, explosion that killed two workers and injured eight others at the Bayer CropScience chemical plant in Institute, W.V.
As a result of ongoing concern regarding the safety of the facility Congress directed the U.S. Chemical Safety Board (CSB) to commission the National Academy of Sciences (NAS) to study the feasibility of reducing or eliminating the inventory of methyl isocynanate (MIC) stored at the Bayer plant.
The video, entitled “Inherently Safer: The Future of Risk Reduction” explores the concept of “Inherent Safety” and could apply at the Bayer facility. The NAS panel noted the goal of inherently safer design is not only to prevent an accident, but to reduce the consequences of an accident should one occur. The video features interviews with NAS panel members and staff as well as commentary from the CSB Chair and investigators.
“The first choice after an accident is to ask how can we improve the disaster so it can’t happen again,” said industry expert and Texas A+M professor Trevor Kletz. “Very often we can change the design very cheaply and very easily, but people don’t do it, they don’t see it.”
The video discusses the findings from the CSB’s investigation and the catastrophic consequences the 2008 accident could have had on the surrounding community.
“The CSB determined that the explosion at Bayer could have caused a release of MIC into the nearby community,” said CSB Chairperson Rafael Moure-Eraso. “And it raised a question – was there an inherently safer alternative to storing and using this highly toxic chemical?”
The NAS report found while Bayer and previous owners of the site incorporated some considerations of inherently safer technology, these companies “did not perform systematic and complete inherently safer process assessments on the processes for manufacturing MIC or the carbamate pesticides at the Institute site.” Thus large amounts of MIC, phosgene, and other toxic materials ended up produced or stored at the site for decades.
There are four main components of inherently safer design as identified by the NAS study. They are substitute, minimize, moderate and simplify.
- Substitute: Replacing one material with another that is less hazardous
- Minimize: Reducing the amount of hazardous material in the process
- Moderate: Using less hazardous process conditions such as lower pressures or temperatures
- Simplify: Designing processes to be less complicated, and therefore less prone to failure.
“Inherently safer design is a philosophy for design and operation of any technology, including chemical processing,” said industry expert Dennis Hendershot. “It’s not a specific technology or a set of tools and activities, but it’s really an approach to design and it’s a way of thinking.”
On March 18, 2011, Bayer said it would not restart MIC production at the plant and would end the manufacturing of carbamate pesticides deemed hazardous by the World Health Organization. The Bayer plant no longer produces or stores MIC.
The CSB said the NAS study and other publications show how the chemical industry could benefit from incorporating the principles of inherently safer design into making decisions – decisions which will satisfy the interests of chemical companies, workers, and members of the communities near their plants.