Organotin stabilisers

These stabiliser systems are now well established for use in PVC items, though their use in PVC-U window profile applications is limited.  As with lead and cadmium based stabilisers, they remain firmly bound within the polymer matrix.  The organotin compounds used as PVC stabilisers are safe to use (22). Indeed, certain organotin stabilisers have been approved for use in food contact packaging under EU regulations (23).

Referring back to the OSPAR Convention, a special Workshop on Plastic Additives was held in Paris in May 1997.  The workshop concluded that there are several different, significant sources of certain organotin compounds found in the environment (e.g. anti-fouling paints, biocidal applications and the use of tributyl-tin) and also that natural processes acting on inorganic tin (methylation) also contributed to environmental levels (24).  Octyl-tin, being only used as a plastic stabiliser is not found significantly in the environment.  The environmental concentrations of organotin compounds used as stabilisers are therefore estimated as very low and should not pose an environmental risk (25).