Blast Rocks Redmond Plant -- Chemicals Explode At Circuit-Board Firm; Damage Extensive, But Nobody Hurt

REDMOND - An explosion caused by the inadvertent mixing of two chemicals at a Redmond circuit-board-manufacturing company blew a 36-by-70-foot hole in the roof and put a 6-inch bulge in a concrete-block wall at the back of the building early this morning.

No one was injured in the explosion at Pacific Circuits on the northeast edge of Marymoor Park, said Redmond fire Capt. Loren Charlston, though some employees reported minor skin and eye irritations.

The 6:25 a.m. explosion took place in a waste-treatment section of the plant at 17550 N.E. 67th Court, which is situated in a light-industrial area of the city.

"We're not sure if it was a valve problem or whether an employee accidentally turned a valve," said Charlston.

George Dalich, director of quality technology and environmental services for Pacific Circuits, said he was on his way to work when an operations staffer at the plant called to tell him about the explosion.

"Is anybody hurt?" Dalich said was his first thought as he heard the news over his cellular phone.

"I think it's a relief," Dalich said. "It's just like we practiced. It's pretty minor compared to what it could be."

As many as 100 different chemicals are used in the plant. Those that caused the explosion were identified as sodium borohydride and nickel sulfamate. Charlston said they combined to create highly flammable hydrogen gas, which then set off the explosion and fire.

The chemicals are initially used in dipping tanks, in which circuit boards are cleaned and coated.

No employees were close to the explosion, though some reported being knocked down by it. "It was a lot of luck," Charlston said.

The force of the blast blew sections of the roof onto the pavement on the north side of the building. At least two vehicles were damaged by the flying debris, including a pickup parked about 10 feet from the buckled north side of the building.

The resulting fire was doused by the building's sprinkler system. The building has a 2,000-gallon tank that collects chemical runoff, Charlston said, so they won't leach into the ground.

Charlston said the factory was designed with the intention of minimizing damage in explosions such as today's - the force of a blast goes upward rather than spreading sideways to injure people who would be nearby.

"This worked quite well because it went up and then out," he said.

Dalich said the company has been in business 20 years and has been in Redmond since 1995. It employs about 430 people and has another plant in Burlington, Skagit County.

Business has been booming. "Everything gets printed circuit boards in it - cars, computers, cell phones," Dalich said.

Frank Ramirez, a janitor, had come to work at 6 a.m. and was in another part of the building when he heard what he called "a loud noise." His wife, Charlene, who works nearby, had rushed to the Pacific Circuits site when she heard about the blast.

A tearful Charlene Ramirez embraced her husband when she found he was not injured.

Some 40 employees were working in a quality-control room 30 feet from the blast.

"It (the roof) went up and then it went down," recalled Marcie Glenn of Tukwila, who started her shift at 5:30 a.m. "And then a big chunk came down on our table. The roof moved up and down, like in an earthquake, about three or four feet."

Several workers said they dived under tables, but then were told by supervisors to leave the plant.

Two hours after the blast, workers said they didn't know what they would do the rest of the day since their cars were in parking lots closed by police and fire lines, and couldn't be moved.