Second, plastics can be destroyed thermally. Furthermore, contamination and the mixing of polymer types generate secondary plastics of limited or low technical and economic value. It reduces future plastic waste generation only if it displaces primary plastic production ( 30) however, because of its counterfactual nature, this displacement is extremely difficult to establish ( 31). Recycling delays, rather than avoids, final disposal. First, it can be recycled or reprocessed into a secondary material ( 22, 26). There are essentially three different fates for plastic waste. Similarly, in 2015, PVC accounted for 11% of nonfiber plastics production (38 Mt) and only 6% of nonfiber plastic waste generation (16 Mt).īy the end of 2015, all plastic waste ever generated from primary plastics had reached 5800 Mt, 700 Mt of which were PP&A fibers. For example, in 2015, 42% of primary nonfiber plastics produced (146 Mt) entered use as packaging and 19% (65 Mt) as construction, whereas nonfiber plastic waste leaving use was 54% packaging (141 Mt) and only 5% construction (12 Mt). ![]() Most of the packaging plastics leave use the same year they are produced, whereas construction plastics leaving use were produced decades earlier, when production quantities were much lower. The different product lifetimes lead to a substantial shift in industrial use sector and polymer type between plastics entering and leaving use in any given year (tables S4 and S5 and figs. For comparison, we estimate that plastic waste generation in 2010 was 274 Mt, which is equal to the independently derived estimate of 275 Mt by Jambeck et al. Thus, in 2015, 105 Mt were added to the in-use stock. We estimate that in 2015, 407 Mt of primary plastics (plastics manufactured from virgin materials) entered the use phase, whereas 302 Mt left it. The building and construction sector, which has used 69% of all PVC, is the next largest consuming sector, using 19% of all nonfiber plastics (table S2). Approximately 42% of all nonfiber plastics have been used for packaging, which is predominantly composed of PE, PP, and PET. Together, these seven groups account for 92% of all plastics ever made. Polyester, most of which is PET, accounts for 70% of all PP&A fiber production. The largest groups in total nonfiber plastics production are PE (36%), PP (21%), and PVC (12%), followed by PET, PUR, and PS (<10% each). ![]() Plasticizers, fillers, and flame retardants account for about three quarters of all additives (table S3). When including additives in the calculation, the amount of nonfiber plastics (henceforth defined as resins plus additives) manufactured since 1950 increases to 7300 Mt. On average, we find that nonfiber plastics contain 93% polymer resin and 7% additives by mass. Data on fiber and additives production are not readily available and have typically been omitted until now. We compiled production statistics for resins, fibers, and additives from a variety of industry sources and synthesized them according to type and consuming sector (table S2 and figs. ![]() Plastic waste is now so ubiquitous in the environment that it has been suggested as a geological indicator of the proposed Anthropocene era ( 11). Contamination of freshwater systems and terrestrial habitats is also increasingly reported ( 7– 9), as is environmental contamination with synthetic fibers ( 9, 10). Plastic debris has been found in all major ocean basins ( 6), with an estimated 4 to 12 million metric tons (Mt) of plastic waste generated on land entering the marine environment in 2010 alone ( 3). Thus, near-permanent contamination of the natural environment with plastic waste is a growing concern. ![]() The only way to permanently eliminate plastic waste is by destructive thermal treatment, such as combustion or pyrolysis. As a result, they accumulate, rather than decompose, in landfills or the natural environment ( 6). None of the commonly used plastics are biodegradable. The vast majority of monomers used to make plastics, such as ethylene and propylene, are derived from fossil hydrocarbons.
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