Hexachlorobutadiene (HCBD)

The substance
Hexachlorobutadiene is a non-flammable, colourless liquid, under usual environmental conditions. It is an oily liquid that is poorly soluble in water. Its odour has been described as 'turpentine-like'.

Use
Hexachlorobutadiene was used principally as a chemical agent, most notably in the recovery of chlorine containing gas in chlorine plants. It was also used in the manufacture of lubricants and rubber compounds. In some parts of the world it has a limited use as an agricultural fumigant. It has also been used to a smaller extent as a heat transfer liquid, and as a hydraulic fluid.

Major emissions
Today hexachlorobutadiene is only produced as an unintended by-product of chemical manufacture processes (chlorinated hydrocarbons). During waste disposal it can be released to the environment when dumped in a landfill. The compound may enter surface and ground water, soil and air. Hexachlorobutadiene does not occur naturally.

Impacts on human health and environment
Hexachlorobutadiene may cause cancer and genetic damage. Hexachlorobutadiene has been found to have a moderate to high toxic effect on aquatic organisms and is associated with death or low growth rates of plants. When released to the environment hexachlorobutadiene does not migrate easily in the soil. It has a moderate potential to accumulate in sediment and to persist in water. Hexachlorobutadiene has a high bioaccumulation potential in fish and shellfish. Persistence, toxicity and tendency to bioaccumulate give rise to concerns over the ability of hexachlorobutadiene to have potential environmental impacts on a global scale. Hexachlorobutadiene is listed as priority hazardous substance in the Water Framework Directive.

Emission to water reporting threshold: 1 kg/year

Data source: European Pollutant Emission Register