Chemical Plant Explosion Near Burley Injures 13

Thirteen people were injured, two critically, on Thursday when an explosion ripped through a mixing tank at a chemical plant.

Cassia County Undersheriff Terry Bingham, the county’s emergency services coordinator, said the cause of the explosion at the Rainbow Farm Products plant southwest of Burley still is unknown.

A plume of chemicals used to create the soil fumigant metam sodium drifted away from the site, prompting the door-to-door evacuation of some 60 people downwind. But the evacuation was called off an hour later after the plume had dissipated, Bingham said.

Two welders working on a second mixing tank were injured critically in the blast. Bingham said one was flown to the burn center at the University of Utah and the other was taken to Cassia Regional Medical Center.

He said other people went to the local hospital with respiratory problems apparently caused by inhaling the chemicals, which have an impact similar to mustard gas, or for decontamination of the corrosive residue on their skin.

It was the first such problem at the plant since it began operating less than a year ago. But county commissioners immediately set an April 14 hearing on whether the equivalent of its operating permit should be revoked.

“We are interested in public safety,” Commissioner Paul Christensen said. “We want to find out what happened and why it happened.”

Commissioners had approved construction of the Rainbow Farm Products plant in November 1995 despite protests from residents concerned about a related company’s record of environmental problems in Arizona. Those included a hydrogen sulfide gas leak from a Tucson area plant in 1994 that reportedly sent 35 people to hospitals.

Bingham said the welders injured Thursday were working on a new chemical mixing tank adjacent to an operating one when workers noticed vapors coming off the operating tank.

As they moved in to investigate, the explosion occurred, blowing the lid off the 30- to 40-foot-high tank, Bingham said. The blast left one of the welders dangling from his safety rope 20 feet off the ground.

“He was hanging upside down on the ladder and is critically hurt,” Burley firefighter Steve Jones said. “He had head trauma and was burned pretty severely.”

Rainbow Farm Products is known to work with carbon disulfide and sodium hydroxide, said Jerry Hockett, supervisory industrial hygienist for the Boise office of the federal Occupational Safety and Health Administration.

Sodium hydroxide, more commonly known as lye, can burn the skin and eyes. Carbon disulfide affects the central nervous system, Hockett said. It can be absorbed through the skin and cause headache, nausea and vomiting.