This is a toxic gas with a pungent smell similar to the smell of rotten eggs. This identifying characteristic can only be perceived by people when the gas is present in low concentrations. Physical complaints: fatigue, sleepiness, irritation of the eyes, inflammation and irritation of the respiratory organs. High concentrations can even lead to pain in the nose and/or bleeding, the human olfactory organ is paralysed preventing the perception of smells and can cause pulmonary embolism with fatal consequences.