Glovebox Explosion at H-P Plant
By SUSAN ENGLISH
San Jose, CA–A woman was hurt in a glovebox explosion on June 8 at Hewlett-Packard Co.`s North San Jose plant, a “III-V gallium arsenide fab” which manufactures components for PC-boards. About 500 workers at the site were temporarily evacuated, and eight who were in the same room with the woman were decontaminated, according to Michele Morey, Fire Department spokeswoman. She said the woman suffered cuts and first- and second-degree burns when a glove box she was working in exploded. The woman was taken to the local medical center and released later in the day.
Apparently the result of a cross connection, the explosion was touched off by the presence of hydrogen through a valve that should have been closed. (Hydrogen is one of many gases used in the fab`s processes.) The hydrogen then became mixed with nitrogen, an inert, non-explosive gas used to purge the hydrogen lines leading to process equipment, and to purge the glove box of any contaminants. There is speculation as to whether the hydrogen was ignited by an electrical spark or by the presence of another gas.
Immediately after the explosion, all gases were shut off, extensive monitoring and checking was done, and the air was exhausted through a scrubber system. Wipe samples were taken, and at presstime, the company was awaiting sample results. Because the explosion took place in an R&D laboratory and not a production area, neither the area nor the glovebox itself were cleanroom rated. The room in which the explosion took place was used as an epitaxial growth area for processing gallium arsenide (GaAs) wafers.
According to a Hewlett-Packard spokesperson, in addition to the company`s standard operating procedures: Toxic Gas Ordinance compliance, health and safety requirements, and the use of personnel protection equipment, on-line hydrogen monitoring and toxic gas monitoring are used to prevent gases from leaking or mixing. As a result of the explosion, the company`s hydrogen alarm response procedures are being reviewed. n