This event involved argon, a simple asphyxiant gas. The facility stored its Argon cylinders inside the 47,000 sq ft building, approximately 55 ft from where the workers were overcome. The Technical Sales representative from National Welders responded to the scene and tested for oxygen deficiency. He tested the system line at 100 psi, which revealed no leaks and suggested that the tank connected to the supply line released gas from the relief valve due to back pressure from the line. The Manufacturing Engineer confirmed that two (2) tanks were found leaking. One of the tanks was completely emptied over the span of a week, while the other was still leaking three weeks after the incident. Each tank held 471 lbs of liquid argon.
At approximately 5:40 pm. on October 17, 2007, a wiring employee came to a press brake to get more pieces from Employee #1, a press operator. Employee #1 turned and put down a piece, collapsed to the floor, and experienced convulsions. The wiring employee panicked and asked the laser operator for help. The laser operator cleared the area. As he stood from the kneeling position, he also became lightheaded and lost consciousness momentarily. All employees were then evacuated by the shift supervisor per their emergency action plan.
It was found that six (6) argon tanks were stored on the inside wall of the 47,000-square-ft building, approximately 55 ft from the press brake department, with one tank supplying the building’s system line for welding operations throughout the facility. Two (2) other employees in the immediate area of the argon tanks also experienced lightheadedness and were transported to the hospital with the aforementioned as a precautionary measure. The Technical Sales representative from National Welders responded to the scene and tested for oxygen deficiency. He tested the system line at 100 psi, which revealed no leaks and suggested that the tank connected to the supply line released gas from the relief valve due to back pressure from the line. The Manufacturing Engineer confirmed that two tanks were found leaking. One of the tanks was completely emptied over the span of a week, while the other was still leaking three weeks after the incident. Each tank has the capacity to hold 471 lbs of liquid argon. Fire Department and Emergency Medical Service cleared the scene for resumption of occupancy after finding no oxygen deficiency present. The company removed all tanks with argon immediately after the incident. Four (4) tanks were placed along the outside wall and two leaky tanks were put approximately 70 yards from the building. The company reconnected the tank to the supply line by drilling through the wall. They also ordered oxygen sensors to be placed throughout the facility and connected them to the company’s alarm system.
Source: https://www.osha.gov/ords/imis/establishment.inspection_detail?id=311596076