Chlordecone, better known in the United States under the brand name Kepone, is an organochlorine compound and a colourless solid. It is an obsolete insecticide, now prohibited in the western world, but only after many thousands of tonnes had been produced and used. Chlordecone is a known persistent organic pollutant (POP) that was banned globally by the Stockholm Convention on Persistent Organic Pollutants in 2009. Synthesis Chlordecone is made by dimerizing hexachlorocyclopentadiene and hydrolyzing to a ketone. It is also the main degradation product of Mirex. History In the U.S., chlordecone, commercialized under the brand name "Kepone", was produced by Allied Signal Company and LifeSciences Product Company in Hopewell, Virginia. The improper handling and dumping of the substance (including the waste materials generated in its manufacturing process) into the nearby James River (U.S.) in the 1960s and 1970s drew national attention to its toxic effects on humans and wildlife. After two physicians, Dr. Yi-nan Chou and Dr. Robert S. Jackson of the Virginia Health Department, notified the Centers for Disease Control that employees of the company had been found to have toxic chemical poisoning, LifeSciences voluntarily closed its plant on July 4, 1975, and cleanup of the contamination began and a 100-mile section of the James River was closed to fishing while state health officials looked for other persons who might have been injured. At least 29 people in the area were hospitalized as a result of their exposure to Kepone. The product is made in a Diels-Alder reaction shared with pesticides like Chlordane and Endosulfan. Chlordecone was not federally regulated until after the Hopewell disaster, in which 29 factory workers were hospitalized with various ailments, including neurological. Chlordecone is cited amongst a handful of other noxious substances as the driver for Gerald Ford's half-hearted approval in 1976 of the Toxic Substances Control Act, which "remains one of the most controversial regulatory bills ever passed". In 2009, chlordecone was included in the Stockholm Convention on Persistent Organic Pollutants, which bans its production and use worldwide. Toxicology Chlordecone can accumulate in the liver and the distribution in the human body is regulated by binding of the pollutant or its metabolites to lipoproteins like LDL and HDL. The LC50 (LC = lethal concentration) is 35 μg/ L for Etroplus maculatus, 22–95 μg/kg for blue gill and trout. Chlordecone bioaccumulates in animals by factors up to a million-fold. Workers with repeated exposure suffer