NORTHWEST : HUNTINGTON BEACH : 100 Evacuated From McDonnell Douglas

A mysterious odor in a microchip laboratory at McDonnell Douglas Space Systems Co. in Huntington Beach sent four people to the hospital for tests Thursday morning and prompted the evacuation of 100 workers.

But hazardous-materials response teams combed the affected building for three hours without finding any sign of a chemical leak or spill.

Local authorities and company officials alike were stumped as to where the odd odor came from and why it made some workers complain of dizziness.

“Nothing has been found,” McDonnell Douglas spokesman Thomas Williams said late Thursday afternoon. “They don’t know what caused it, where it came from or what it was.”

The evacuation of Building 28 on the 250-acre complex began after workers who arrived about 7:30 a.m. noticed a strange “powdery” odor, Williams said.

Safety workers, who routinely monitor the air in the “clean rooms” where the microchips are made, detected some odd readings and decided to clear the building, Williams said.

Three men and one woman who complained of dizziness and nausea were taken to Fountain Valley Regional Hospital and Medical Center, but they were released after tests of their blood-gas levels proved normal.

The building is used to manufacture highly advanced gallium arsenide microchips, which are used in research by both McDonnell Douglas and by the U.S. Department of Defense, Williams said.

Although solvents, inert gases and other chemicals are used there, Williams noted, the unit has never had a spill or leak.

While engineers and technicians stood in the parking lot looking on, hazardous-materials response crews from Westminster, Huntington Beach and Newport Beach fire departments, clad in in bright yellow space-style suits, took turns scouring the building with air-monitoring devices. But they found no trace of the phantom fumes, according to Birgit Davis, spokeswoman for the Huntington Beach Fire Department.

Williams said business will resume as usual at the plant today while the company continues to investigate.