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IPEN Body Burden Community Monitoring Handbook OrganometalsOrganotin Compounds Chemical Name: Organotin compounds comprise mono-, di-, tri- and tetrabutyl and triphenyl tin compounds. They conform to the following general formula (n-C4H9)nSn-X and (C6H5)3Sn-X, where X is an anion or a group linked covalently through a hetero-atom. CAS Number: Properties: Solubility in water: at 25°C; vapour pressure: mm Hg at 20°C; log KOW: 3.19 - 3.84. In sea water and under normal conditions, TBT exists as three species (hydroxide, chloride, and carbonate). Discovery/Uses: They are mainly used as antifouling paints (tributyl and triphenyl tin) for underwater structures and ships. Minor identified applications are as antiseptic or disinfecting agents in textiles and industrial water systems, such as cooling tower and refrigeration water systems, wood pulp and paper mill systems, and breweries. They are also used as stabilizers in plastics and as catalytic agents in soft foam production. It is also used to control the shistosomiasis in various parts of the world. Persistence/Fate: Under aerobic conditions, TBT takes 1 to 3 months to degrade, but in anaerobic soils may persist for more than 2 years. Because of the low water solubility it binds strongly to suspended material and sediments. TBT is lipophilic and tends to accumulate in aquatic organisms. Oysters exposed to very low concentrations exhibit BCF values from 1000 to 6000. Toxicity: TBT is moderately toxic and all breakdown products are even less toxic. Its impact on the environment was discovered in the early 1980s in France with harmful effects in aquatic organisms, such as shell malformations of oysters, imposex in marine snails and reduced resistance to infection (e.g. in flounder). Molluscs react adversely to very low levels of TBT (0.06-2.3 ug/L). Lobster larvae show a nearly complete cessation of growth at just 1.0 ug/L TBT. In laboratory tests, reproduction was inhibited when female snails exposed to 0.05-0.003 ug/L of TBT developed male characteristics. Large doses of TBT have been shown to damage the reproductive and central nervous systems, bone structure, and the liver bile duct of mammals. Source: UNEP Chemicals, Regional Reports of the Regionally Based Assessment of Persistent Toxic Substances Program (2002) Available from: http://www.chem.unep.ch/pts UNEP Chemicals 11-13, chemin des Anemones CH-1219 Chatelaine, GE Switzerland. 
IPEN Body Burden Community Monitoring Handbook - 2003 |
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