Argon gas used as part of a welding operation caused the asphyxiation death of an apprentice welder working in a confined space. He was completing welding work inside a tank being constructed of titanium. Because titanium is a reactive metal, the welding bead of molten metal must be blanketed under the inert gas argon until it cools. Argon is heavier than air and will settle in low areas in confined spaces, displacing oxygen. The victim had been in the tank for an hour before the foreman found him. Efforts to revive him were unsuccessful. Confined spaces and toxic gases are a deadly combination. […]