Abstract: At approximately 7:30 a.m., on July 17, 1997, a specialty painting company employee was contracted by Mission Bell Winery, Canandaigua Inc. to paint a wine storage tank. The wine storage tank was a confined space and the employee connected his airline respirator hose to the winery's power equipment air system. The air system was not designed to be used as a source for supplied air respirators and nitrogen is added to the air system regularly to maintain proper pressure in the power equipment through a cross connection. As the employee was painting the wine storage tank and wearing his airline respirator, nitrogen was cycled through the air system. The employee was asphyxiated and killed. He was found by Mission Bell employees. Mission Bell representatives stated that no winery employees were allowed to connect airline respirator hoses to that particular air system. They also stated that they were not aware of the fact that the contracted employee had connected to the air system for use as breathable air. Further investigation revealed the employee had modified his airline hose to allow connection to the air system and the oxygen level in the airline hose had dropped to zero when the nitrogen was added.