Hexachlorobutadiene in freshwater and marine water
Toxicant default guideline values for protecting aquatic ecosystems
October 2000
Extracted from Section 8.3.7 ‘Detailed descriptions of chemicals’ of the ANZECC & ARMCANZ (2000) guidelines.
The default guideline values (previously known as ‘trigger values’) and associated information in this technical brief should be used in accordance with the detailed guidance provided in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.
Description of chemical
Hexachlorobutadiene (CAS 87-68-3) (hexachloro-1,3-butadiene) is a by-product of the production of chlorinated hydrocarbons. It is used as a solvent in chemical industries and as a heat transfer fluid in electrical transformers (CCREM 1987). The presence of hexachlorobutadiene in the environment results from anthropogenic sources such as volatilisation and from industrial wastes. Sorption to sediments is considered to be an important mechanism for the removal of hexachlorobutadiene from the water column (CCREM 1987). Little information is available regarding biodegradation.
Hexachlorobutadiene is acutely toxic to freshwater fish and invertebrates over a relative narrow range of 90 to 326 µg/L (USEPA 1980l). Acute toxicity to the fathead minnow (96-hour LC50) occurred at 100 µg/L and chronic toxicity occurred at 9.3 µg/L (USEPA 1980l). Bioconcentration factors for aquatic animals ranged from 29 to 7000 µg/L (USEPA 1980l, Ahmad et al. 1984). Acute toxicity (96-hour LC50) to marine fish occurred at 1600 µg/L and for a marine crustacean, 1200 µg/L. USEPA (1986) reported a lowest acute figure of 32 µg/L.
Guideline
Insufficient data were available to derive a reliable guideline figure. A freshwater environmental concern level (ECL) (see Section 8.3.4.5 of the ANZECC & ARMCANZ 2000 guidelines) of 0.04 µg/L was calculated from unscreened chronic data using an assessment factor (AF) of 200. A marine ECL of 0.03 µg/L is suggested from the unscreened USEPA data. These figures could be adopted as low reliability trigger values for use only as indicative interim working levels.
References
Ahmad N, Benoit D, Brooke L, Call D, Carlson A, DeFoe D, Huot J, Mariority A, Richter J, Schubat P, Veith G & Wallbridge C 1984. Aquatic toxicity tests to characterise the hazard of volatile chemicals in water: A toxicity data summary. Parts 1 and 2. EPA-600/3-84-009. US Environmental Protection Agency, Washington DC.
ANZECC & ARMCANZ 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.
CCREM 1987. Canadian water quality guidelines. Canadian Council of Resource and Environment Ministers, Ontario.
USEPA 1980l. Ambient water quality criteria for hexachlorobutadiene. Criteria and Standards Division, US Environmental Protection Agency, Washington DC. EPA-440/5-80-053.
USEPA 1986. Quality criteria for water. US Department of Commerce, National Technical Information Service, US Environmental Protection Agency, Springfield, Virginia. PB87-226759, EPA 440/5 86-001.
