CSB LETHAL A chemical explosion at T2 Laboratories in 2007 killed four workers.

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A runaway exothermic chemical reaction is the likely cause of a fatal accident at T2 Laboratories, a Jacksonville, Fla., chemical manufacturer, the Chemical Safety & Hazard Investigation Board (CSB) says in a report released at a public meeting in Jacksonville last week.

The Dec. 19, 2007, accident was one of the most destructive ever investigated by the board, shattering nearby buildings and sending debris a mile away, says Robert Hall, CSB investigation supervisor. The blast killed four of the company's 12 employees, including the facility's co-owner, a chemical engineer. It injured four other workers and 28 community members. The plant was destroyed.

Triggering the accident was a reaction to make the octane-enhancing gasoline additive methylcyclopentadienyl manganese tricarbonyl (MCMT) in a 2,400-gal reactor. The batch reactor had been in use since 2004, but during start-up on the day of the accident, a loss of cooling led to uncontrollable rises in temperature and pressure. The reactor burst, igniting its contents and creating an explosion equivalent to 1,400 lb of TNT, the board says.

Although the company was led by a chemist and a chemical engineer, neither was familiar with process controls for highly reactive chemicals, such as those used to formulate MCMT, Hall and CSB Chairman John Bresland say. The board recommends that the American Institute of Chemical Engineers and the Accreditation Board for Engineering & Technology work together to include reactive chemical education in undergraduate chemical engineering education. Less than 11% of universities now include such courses in chemical engineering curricula. CSB's educational recommendation angers the United Steelworkers and other chemical workers' unions. The group says CSB is "abrogating its mandate" to investigate accidents and urge CSB to repeat past recommendations that the government toughen reactive chemical regulations.

A previous CSB study found that over a 20-year-period, U.S. chemical companies had 167 serious reactive accidents, killing 108 workers and injuring hundreds more. The T2 explosion shows these accidents continue to occur, CSB notes.

Since 2002, the board has urged without success that EPA and the Occupational Safety & Health Administration expand their regulations to include reactive chemicals and mixtures. Those recommendations remain open, Bresland notes.

"It will be years before an educational recommendation has any impact," Michael J. Wright, United Steelworkers' director of health, safety, and the environment, tells C&EN. "The recommendation gives people working in and living around the plants little comfort. The board needs a deeper analysis, and they didn't provide it."