A chemical widely-used in water purification, disinfectants, bleach and mustard gas. It is also commonly used in manufacturing various products such as paper, pesticides, paints, petroleum products, plastics and solvents. Chlorine causes some harm to the environment and is particularly harmful to water and soil organisms. Chlorine dissolves when mixed with water. It can also escape from water and enter air under certain conditions. Most direct releases of chlorine to the environment are to air and to surface water.