A class of organic compounds that contain chlorine. In general, many chlorine compounds are toxic and carcinogenic. The term 'organochlorine' is also used to refer specifically to chlorinate hydrocarbon insecticides. As insecticides, organochlorine compounds are divided into bioaccumulative (DDT and dieldrin) and nonaccumulative (lindane, chlordane). Many of these compounds have been banned or their use is restricted.