Technoeconomic and environmental assessment of industrial organotin compounds

Current uses of organotins include heat stabilizers for polyvinyl chloride (PVC), catalysts for polyurethane foam and silicone rubber, biocides, and animal health products. Domestic production consumption in 1982 is about 28 million pounds, and overall growth is estimated at 7 percent per year. Physical properties of organotins, including solubility in water, octanol-water partition coefficients, and Freundlich adsorption isotherm constants, are not well characterized. Analytical methods for tin in environmental and biological matrices involve concentration, separation, and identification by chromatography, spectrometry, and spectroscopy. Environmental fate and effects of organotins are not well understood. Degradation reactions may yield a complex set of products, including inorganic tin oxide. The effects of exposure of workers and release of organotins to the environment at point sources have been documented. Nonpoint sources of environmental exposure include discard and sanitary landfill disposal of plastics and direct release of biocides to aquatic or marine environments. Other dissipative uses of organotins which pose potential human risk include PVC food wrapping and bottles and rigid potable water pipe. The long term health effects of low level exposure to organotins are not known. Toxic metal cycling in the environment, including biomethylation of inorganic tin by naturally occurring bacteria, is of rising concern.