Hazardous conditions exist which may result in spontaneous combustion when __________.

Correct Answer: Option B — oil soaked rags are stowed in the machine shop

Improperly stowed oil-soaked rags undergo rapid atmospheric oxidation in confined spaces where heat dissipation is restricted, steadily increasing temperature until self-ignition occurs. Metal turnings and dry powdered aluminum present different hazards, making oil-soaked rags the classic spontaneous combustion risk.