Abstract: Employee was removing a load from a 26 in. diameter hot isostatic press (HIP) pressure vessel with a 9 ft space from the opening to the heat pedestal at the bottom, when graphite spacers fell from the graphite plates that held the tungsten metal parts to the bottom of the HIP vessel. Because the next load would not fit with the spacers in the bottom, Employee #1 was sent down to get them. He was retrieving the second spacer when he was overcome by argon gas. The HIP pressure vessel is used to cure tungsten steel at a temperature of 1,360 degrees C and a pressure of 15,000 psi, using argon gas. The vessel atmosphere had not been tested or ventilated prior to entry; employees had no training; and no rescue procedures with lifelines and respiratory equipment were available. Employee #1 died of asphyxia.