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Organic tin compounds - total as Sn

organic tin compounds

SPRI Emission Reporting Threshold
5.00 Kg/yr Pollutant Emissions to Water
5.00 Kg/yr Pollutant Emissions to Waste Water
50.0 Kg/yr Pollutant Emissions to Land
Disclaimer
This sheet is a generic summary, designed to give the reader a basic level of background information about the substance in question. Great care has been taken to represent as effectively and correctly as possible the broad range of (not necessarily consistent) information which is available from a variety of sources. The reader must accept therefore that this sheet has no legal status and cannot be relied upon in any legal proceedings. SEPA disclaims any responsibility or liability whatsoever for errors and omissions in this sheet.
What is it?
Organotins are a group of compounds containing tin bound to organic (carbon-containing) components. The properties depend on the specific type. For example: triphenyltin compounds are colourless solids which do not easily evaporate and are insoluble in water; tributyltin oxide is a colourless liquid which does dissolve slightly in water; dibutyltin chloride is a white solid which will dissolve in hot water.
What is it used for?
The most widely used organotins are those with two and three substituted components (di-substituted and tri-substututed respectively). Di-substituted organotins are used as stabilisers and strengthening agents in plastics. Tri-substituted organotins are used as wood, stone and textile preservatives, as marine pesticides (biocides, fungicides, bactericides, anti-fouling agents) and as disinfectants.
Where does it come from?
Most releases of organotin compounds occur during their manufacture and use in the chemical industry and in marine applications. Small amounts are released naturally from the earth's crust.
How might it affect the environment?
At a local level organotin compounds cause most concern in marine environments (where they are most widely used). Some organotins are very toxic to algae, molluscs, crustacea, fish and some marine mammals. The effects include damage to the immune system and, for marine mammals, the hormone system (which is essential for the proper function of the body). Organotins can accumulate in fish, animals and plants and can concentrate up the food chain. Organotins are not thought to have any environmental effects at a global level.
How might exposure to it affect human health?
Exposure to normal environmental concentrations of organotins is unlikely to significantly damage health. Long-term exposure to higher levels in occupational settings or accidental exposure to extremely high levels may lead to breathing problems, eye and skin irritation, interference with the function of the brain and the immune and nervous systems. The precise nature of the effects depends on the type of organotin in question and the type of exposure.
What steps are being taken to limit the potential impacts?
In the UK (including Scotland) releases of organotins are controlled through regulations on pollution of surface waters; and the pollution, prevention and control regulations. European Directives controlling emissions of organotins include those concerned with the pollution of aquatic environments (76/464/EEC); and restriction of the marketing and use of certain chemicals (76/769/EEC). Internationally, releases of organotins are controlled through the OSPAR and Helsinki conventions which protect the marine environments of the north-east Atlantic and Baltic seas respectively. Also, the Marine Environment Protection Committee of the International Maritime Organisation (IMO) are drafting legislation which would ban the use of organotins as anti-fouling agents on ships.