The chemicals industry as a whole, and the PVC production chain in particular, are only very minor contributors to dioxins’ emissions throughout the world (much less than 1 %). As an example, a survey carried out in 1993 attributed to the entire chemical industry only 0.5 gram/year of dioxin emissions out of a total of 484 grams emitted per year in the Netherlands.
In 2001 US PVC manufacturers carried out an extensive monitoring programme, to evaluate the extent of dioxins releases to the open environment as well as to secure landfill. The most likely estimate was 32 g I-TEQ/yr with approximately 12 g being released into the open environment and about 19 g disposed of in secure landfill. This compared to a total released to air of several thousands of grams.
A recent eco-profile of the PVC industry showed that the total emissions of dioxins in Western Europe related to the production of PVC are now around 2 g I-TEQ per year
Formation of very small quantities of dioxins can only occur in the ethylene oxychlorination, which is one of the process steps leading to the production of VCM. These dioxin molecules are adsorbed by the solid catalyst and hence are easily contained by filtration and controlled treatment of this catalyst.
The production of PVC itself and of PVC-based products takes place at temperatures far below those required for dioxin formation.
