Calculating the Swedish economy‐wide emissions of additives from plastic materials
Poster (konferens), 2012
"Plastics" are very diverse, multipurpose and ubiquitous materials found in very many types of products like shoes, cars, bags and containers. Plastic materials have these many uses due to the possibility of modifying the polymer matrices constituting the bulk material in very many ways with a large number of additives; compounds that are more or less permanently attached in the matrix. Some of these additives have properties with high importance for the final functionality of the product. Flame retardants is a well know example of an additive making otherwise combustible plastic materials (often textile fibres) much less apt for taking fire. There are however a very large number of substances which have got less attention.
Our modeling approach aims at a quantification of emissions from a large set of materials occuring in a typical developed country - Sweden. The approach is "bottom-up" in the sense that it is not based on a back-calculation of measured emitted substances. It is rather a combination of a diffusive mass-transfer emission model with models providing information on aggregated product surface areas and material composition of these areas. This combination of the physico-chemical modeling of substance release from a surface under a specific set of environmental conditions, which also rely on substance and material characteristics, and the substance and material flow models, based on trade statistics, longevity data and product properties, is a unique emission model giving the possibility to feed in results to environmental fate modelling and environmental analysis.
Results show that textiles, and the huge number of substances occuring in them, are of particular interest due to the fact that this product category constitutes the largest surface area. Due to wear and washing textiles are also fragmented, giving very small fibers and fragments contributing to a further increased surface area that increase the emission rate from the fibre materials in textiles. The result indicate that a number of substances, beside known environmental pollutant, are emitted from textiles.