The converters are often located on the brink of the location to finish articles. Over 98% percent of the finished EPS articles consist of the air; the products are extremely light and are can easily transport over long distances. The various uses of EPS/XP both ashore and stumped end in the increased likelihood of those materials entering the ocean from many sources.

Under outdoor conditions, weathering and aging of microplastics can cause degradation of the materials, but the mechanisms and degradation times depend upon the sort of plastic, the content of additives and therefore the area of deposition. Generally, the mechanisms affecting the degradation processes of macroplastics into microplastics and nanoplastics are photodegradation, hydrolysis, mechanical degradation and thermal degradation besides biodegradation.

Releases of expandable Polystyrene

Until the polystyrene (PS) pellets are expanded by the converters, the possible losses are going to be as PS pellets and out of doors the scope of this study. However, some indicative estimates of the losses of PS pellets are provided. These lifecycle stages include the assembly of the PS pellets, loading and transport to the converters and unloading by the converters.

The majority of the production of the expansible PS takes place in Germany where most river basins drain to the North Sea and therefore the Black Sea and few drains to the Baltic Sea. As discussed in section 1.2, only 4% of the German population lives in the Baltic catchment basin. Furthermore, the production of chemicals and plastic raw materials in Germany is specially situated within the river basins of the Rhine, Danube, Weser, and Elbe, which don't drain to the Baltic. Release from production consequently would mainly occur from Poland, Finland and possibly Russia, but no production facilities in Russia within the drainage areas of the Baltic Sea are identified.

A small fraction of the pellets lost to the drain would ultimately find yourself within the Baltic but the further fate of the PC pellets has not been investigated. The applied emission factors from the united kingdom study are about ten times above the reported losses from Danish converters under normal conditions, but the United Kingdom data are utilized to require under consideration larger accidental losses and therefore the possibility that releases could also be significantly higher in some of the countries.

In recent years, many of the producers and converters have committed themselves to Operation Clean Sweep and are reducing emissions; the resulting emission factors might be significantly lower, as indicated by the recent investigations by a Swedish manufacturer of polystyrene cited above (Karlsson et al., 2018) and therefore the reported data from Danish converters.

Even though data are very limited, this first estimate indicates that the releases of XPS with packaging foam might be significant, but likely not the main source of EPS/XPS to the Baltic.