Hexachloroethane

Hexachloroethane, also known as perchloroethane (PCA) is the organochlorine compound with the formula (CCl3)2. It is white solid at room temperature with a camphor-like odor. It has been used by the military in smoke compositions, such as base-eject smoke munitions (smoke grenades).
Manufacture.
Chlorination of tetrachloroethylene at 100–140°C with the presence of ferric chloride is the most commonly used commercial production method, however several other methods exist. A high purity form can be produced in a small scale by reacting chlorine together with barium carbide. In September 1997, it was reported as no longer being produced in the United States for commercial distribution, but was produced as a by-product of industrial chlorination process.
Applications.
Hexachloroethane has been used in the formulation of extreme pressure lubricants. It has also been used as a chain transfer agent in the emulsion polymerization of propylene tetrafluoroethylene copolymer. Hexachloroethane has been used as an anthelmintic in veterinary medicine, a rubber accelerator, a component of fungicidal and insecticidal formulations as well as a moth repellant and a plasticizer for cellulose esters.
Hexachloroethane has been used in the manufacture of degassing pellets to remove hydrogen gas bubbles from molten aluminum in aluminum foundries. This use, as well as similar uses in magnesium, is being phased out in the European Union. 
Use as smoke agent.
Smoke grenades, called hexachloroethane (HCE) smoke or HC smoke, utilize a mixture containing roughly equal parts of HCE and zinc oxide and approximately 6% granular aluminium. These smokes are toxic, which is attributed to 
the production of zinc chloride (ZnCl2). According to Steinritz et al., "Due to its potential pulmonary toxicity," zinc chloride producing smoke grenades "have been discharged from the armory of most western countries (...)."
Toxicity.
Hexachlorethane is not particularly toxic when taken orally, but is considered to be quite toxic by skin adsorption. The primary effect is depression of the central nervous system. The IDLH is given as 300 ppm and the OSHA PEL is 1 ppm (skin). It is reasonably anticipated to be a carcinogen.