Stabilisers types The main types of stabiliser systems are based either on lead, mixed metals (principally barium/zinc or calcium/zinc), tin or cadmium, although use of cadmium systems is currently being phased out in Europe. Approximately 170,000 tons of stabilisers are used in Europe every year. The type of product used breaks down as follows: (2000 Industry Figures) Selection of the appropriate variety was initially founded upon empirical grounds. Because of the vast variety of uses of PVC in society, and because of the complexity of processes and application, the selection of the appropriate stabiliser system requires considerable knowledge and expertise of process equipment polymer choice and final application. Chemically, the stabiliser functions by reacting with any chlorine (in radical or hydrochloric acid form) freed during the thermal stress of processing or use. Light-induced degradation is more complex and the protective effect of stabilisers can be reinforced with specific UV-stabilisers. To suit the needs of a particular application, a stabiliser "one-pack" is often formulated, including one or more of the above products. The one-pack often includes a mixture of internal- and external lubricants and other processing aids, based on extensive industry know-how. In addition, plasticisers, pigments, fillers, impact modifiers and other additives are used to customise PVC to specific end-uses. To learn more about the main categories of PVC stabilisers click on your selection to the left.