Federal OHS investigators are looking into a leak of phosphine gas at a customs facility. Workers discovered a flame at the neck of a cylinder of the gas. But when firefighters arrived, the flame had gone out. It appears that the cap protecting the tank was damaged. Phosphine gas is a colourless gas with a fish or garlic-like odour that may be fatal if inhaled and can damage the lungs, heart, upper respiratory tract and central nervous system.