Abstract: On September 8, 1988, Employee #1 and a coworker were sandblasting and painting grating and railings. Employee #1, the sandblaster, used an abrasive blasting respirator air line that was hooked into the plant's air supply. But the plant air supply was not grade D breathing air and was intended to be used only for valves, gauges, and pneumatic tools. Because the air compressor was shut down for maintenance, nitrogen backfed into the plant air line. No one from the company informed Employee #1 or the painter that the line now contained nitrogen. Employee #1 donned the abrasive blasting helmet, inhaled the nitrogen, and was asphyxiated. He died.