Procedure Error Caused Chlorine Leak At Kaiser Supply Line To Rail Cars Wasn’T Shut Off Properly

Human error led to the chlorine leak Monday that sent 11 workers at Kaiser Aluminum’s Trentwood plant to the hospital, fire officials said.

The Valley Fire Department had been at the site earlier that day to prepare for just such an incident.

One worker remained hospitalized Wednesday. Of the others requiring treatment, three were kept overnight, said Susan Ashe, spokeswoman for Kaiser.

“We’re just real grateful there were no serious injuries,” Ashe said.

The accidental release of chlorine happened during a change of rail cars that carry the chemical, used to remove impurities from the molten metal. An employee in the remelt and casting area of the plant discovered the problem just before 4 p.m.

“It was just an error in the procedure,” Fire Marshal Paul Chase said.

When the rail cars were switched, the supply line connecting the cars to the plant system was not properly shut off, he said. When the line was hooked up to a scrubber to be purged of remaining chlorine, the system “burped” and released the chemical into the plant, Chase said.

The Fire Department had to retrace its route from earlier in the day when firefighters trained for such an incident.

“What was a half-hour drill turned into a five-hour real incident,” Chase said.

Kaiser, the Steelworkers Union and the state Department of Labor and Industries are conducting their own investigations of the incident.

“A fatality didn’t occur, but the potential was there,” said Darren Hill, acting safety chairman for the labor union. “In our minds it was real serious, especially with the amount of people affected and the amount of time they had to spend in the hospital.”

Labor and Industries is investigating the leak as a catastrophic incident - defined as causing two or more workers to be hospitalized.

Firefighters go through routine training at the Trentwood facility. With 65 acres under one roof, firefighters have to know their way around, Chase said.

Trentwood, which produces flat-rolled aluminum products, employs about 1,400 workers.

Hannelore Sudermann can be reached at (509) 459-5419 or by e-mail at hannelores@spokesman.com.