Inspection Detail

Inspection: 310093000 - Coastal Circuits

Inspection Information - Office: Foster City District Office

Investigation Summary

At 3:00 a.m. on Sunday, September 23, 2007, Employee #1 was working alone on the Saturday evening swing shift. His father, who also worked at the plant, became worried when his son did not return home from his shift. He went to the plant at approximately 1:00 a.m. and reportedly found him immersed head first in a small rinse tank (18 ft. wide x 24 ft. long x 36 ft. deep) on the plating line. Employee #1's father phone for help. Redwood City EMTs responded and pronounced Employee #1 dead at the site. Employee #1's typical shift was the graveyard shift from 12:30 a.m. to 9:00 a.m.. On the evening of September 22nd, he was asked to come in to run the plating line for a special order. According to the company staff, he was supposed to work only from 2:00 p.m. to 6:00 p.m.. However, he was reported by a coworker to be still working at 6:00 p.m. when she left. Employee #1's copper plating log indicates that he actually began work at around 12:00 Noon. His last entry on the log was 4:40 p.m. At about 6PM, he had a conversation with a coworker as she was leaving work. Thiscoworker was the last person remaining in the plant besides Employee #1, After she left, he was working alone. Sometime after Employee #1's coworker left the premises, Employee #1 did return to the plating line. His plating log shows that he had last extricated circuit boards from tank number 3 at 4:40 p.m. At some time later, Employee #1 placed 6 plates in a 5 minute hydrochloric acid tank (#110) at the head of the small tank line. According to the plating schedule that Employee #1 knew well, he would have then removed those and placed them in a one minute rinse tank (#111) immediately adjacent to #110. Employee #1 would have then placed 6 more plates in the #110 tank. Those plates were still in their respective tanks, and there was no other work in any of the small acid rinse tanks or the larger plating tanks when the manager and the emergency response personnel arrived later the next morning. When Employee #1 was found, he was not wearing his safety glasses. They were hanging on the wall above the work table. At autopsy, showed there was no sign of chemical burns to either eye. He was not wearing a respirator or face shield. Some edema from a white area about the size of a quarter was found in his throat, but the coroner believed that it was not likely the result of a concentrated acid, such as might have come from tank #110. He was also not wearing his smock. There was considerable erythema on the face and upper torso. The coroner concluded that the erythema was the result of his immersion in the tank. There were some abrasions of his left shoulder, most likely resulting from his efforts to extricate himself from the tank. At the time of the accident, the distance from the walking and working surface of the plating line to the top of the line of small tanks was approximately 24 inches. Distance from the top of the larger plating tanks was from 27 to 32 inches. Measurements did show that just below the copper plating line where Employee #1 worked, an ammonia etch operation was giving off ammonia vapors in concentrations high enough to be quite irritating depending on exposure position. One particular source point, which was not a regular work station, was found and shown to management for remediation.

Keywords: EYE, THROAT, AMMONIA, SAFETY BELT, HYDRAULIC CYLINDER, NECK, DROWN, FACE, RESPIRATOR