Octyl tin maleate

Awareness of the problem developed in the mid 1970s when it was found that mineral waters sold in polyvinyl chloride (PVC) bottles contained measurable amounts of vinyl chloride monomer. Vinyl chloride is a known carcinogen. The Codex Alimentarius Committee on Food Additives and Contaminants has set a guideline of 1 ppm for vinyl chloride monomer in PVC packaging and 0.01 ppm of the monomer in food (Institute of Food Technologists 1988). Another additive found in some PVC plastics is octyl tin mer-captoacetate or octyl tin maleate. Specific regulations for these chemicals exist in the Canadian Food and Drugs Act. 

Generally toxic, with aromatic amines showing carcinogenic tendencies. Newer types less toxic Considered non-toxic as also used in foods. Recently investigated and found non-carcinogenic Only class of tin compound classified as of low toxicity and used in medical applications e.g. di-(n-octyl)tin maleate polymer... 

Di-n-octyl tin maleate Study of degradation products of this compound produced on processing [97]... 

Among these heat stabilisers, those containing tin (such as tin mercaptides, and tin carboxylates or maleates) are considered to be the most efficient, and can be used in a wide variety of applications. Metallic tin is harmless but there are suspicions that organotin-compounds can be toxic to the central nervous system and the liver. However, tin stabilisers have a low capacity for migrating, and hence they are still considered to be safe. Tin stabilisers such as methyl and octyl tins are used in food contact applications. For PVC, it is believed that tin stabilisers act as HCl scavengers (generating tin chloride) as well as an antioxidant. Thio-tin compounds (preferred for rigid pipe extrusions and profiles (for window frames) of PVC) may develop an odd odour due to sulfur. 

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