Arsenic and its compounds

Pure arsenic is a grey-coloured metal but is rare in the environment. It has a crystalline, metallic-looking appearance and is odourless. Arsenic is usually found combined with one or more other elements such as oxygen, chlorine and sulphur. Arsenic compounds are naturally present in the environment at low levels. Inorganic arsenic compounds are usually solids at environmental temperatures, of low volatility and variable solubility in water.