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Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities (2023)

Chapter: 3 Management and Sourcing of Plastics Waste

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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
×
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Suggested Citation:"3 Management and Sourcing of Plastics Waste." National Academies of Sciences, Engineering, and Medicine. 2023. Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities. Washington, DC: The National Academies Press. doi: 10.17226/27172.
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33 The reuse of plastics waste in infrastructure, or any other application, is dependent on the availability of plastics waste in sufficient quantity and quality, at the time and place of need, for remanufacturing and reuse enter- prises. That is to say, the reuse of plastics waste is dependent on the plastics waste management system and all its components. This system provides the supply chain for plastics waste feedstock for remanufacturing and reuse. In the United States, some aspects of this supply chain have been in place for decades and are well developed. Overall, however, the plastics waste management system in the United States is at an early stage of development. There are three main methods to manage plastics waste: landfilling, in- cineration, and recycling. This chapter examines the current plastics waste management system in the United States with an emphasis on recycling. It provides some background into how this system has evolved and the fac- tors that have driven that evolution. Post-consumer1 and post-industrial2 sources and methods of collection and processing are described. Avail- able data for supply and demand for different types of plastics waste are presented. 1 Post-consumer waste refers to finished products that are used by consumers and then recycled. 2 Post-industrial waste refers to waste generated from the manufacturing process. For example, during the fabrication of plastic bottles, excess material is trimmed, leaving plastic scrap behind. 3 Management and Sourcing of Plastics Waste

34 RECYCLED PLASTICS IN INFRASTRUCTURE PLASTICS WASTE MANAGEMENT IN THE UNITED STATES Global plastics waste generation in 2019 was estimated to be 353 million metric tons (MMT) (OECD 2022) and represented 12 percent of all mu- nicipal solid waste (MSW). According to the U.S. Environmental Protection Agency (USEPA), the United States generated 36 MMT of plastics waste in 2018 (USEPA 2022), although others estimate U.S. plastics waste at 42 MMT (Law et al. 2020), 44 MMT (Milbrandt et al. 2022), and 73 MMT (OECD 2022). Figure 3-1 and Table 3-1 further break down U.S. plastics waste by material type and use, as well as their waste management path- ways (Milbrandt et al. 2022). Linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) represent the largest category of plastic type in U.S. waste, primarily film, wraps, and bags. The first steps in plastics waste management include storage, collec- tion, and primary recyclables processing. These are followed by second- ary recycling (i.e., where material is reused in some other way without FIGURE 3-1 Plastics waste composition in the United States (percent by weight) by material type and resin code. SOURCE: Milbrandt et al. 2022.

35 T A B L E 3 -1 P la st ic s W as te D is po sa l i n th e U ni te d St at es Pl as ti cs W as te M at er ia l, by R es in Pl as ti cs W as te M an ag em en t Pa th w ay s Pl as ti cs W as te b y Pr od uc t T yp e T ot al P la st ic s W as te M an ag ed L an dfi lle d C om bu st ed R ec yc le d D ur ab le N on du ra bl e C on ta in er s an d Pa ck ag in g kt % k t % kt % kt % % % % PE T 5, 98 6 14 4 ,5 54 76 53 3 9 89 9 15 8 4 89 H D PE 7, 91 0 18 6 ,4 48 82 69 3 9 76 8 10 14 3 83 PP 8, 18 9 19 7 ,2 02 88 71 6 9 27 1 3 41 6 53 L D PE /L L D PE 15 ,1 39 34 1 3, 29 0 88 1, 52 4 10 32 5 2 10 3 88 PV C 69 9 2 6 14 88 66 9 18 3 25 13 62 PS /E PS 3, 09 4 7 2 ,8 15 91 26 3 9 16 1 33 43 24 O th er 3, 11 5 7 2 ,7 96 90 27 8 9 41 1 88 7 5 T ot al 44 ,1 31 10 0 3 7, 72 0 86 4, 07 3 9 2, 33 9 5 24 7 70 N O T E S: B ec au se o f da ta r ou nd in g, s om e to ta l v al ue s m ay s ho w a s m al l d is cr ep an cy t o th e su m o f pr es en te d da ta . k t = 1, 00 0 m et ri c to ns . D ur ab le pr od uc t in di ca te s a se rv ic e lif e gr ea te r th an 3 y ea rs ; n on du ra bl e pr od uc t in di ca te s a se rv ic e lif e le ss t ha n 3 ye ar s. SO U R C E : M ilb ra nd t et a l. 20 22 .

36 RECYCLED PLASTICS IN INFRASTRUCTURE reprocessing), tertiary recycling (i.e., chemically altering material to reuse it), incineration, or landfilling (sanitary and dumpsites). The Organisation for Economic Co-operation and Development (OECD) estimated that in 2019, 60 MMT of plastics waste were incinerated globally and 162 MMT of generated waste were disposed of in landfills. Incineration often results in a recovery of energy, which has some environmental and economic benefits, although the CO2 produced contributes to climate change. Plastics degrade quite slowly under landfill conditions, so, other than accomplishing carbon sequestration, there are no benefits to landfilling plastics (Staley and Barlaz 2009). Figure 3-2 provides chronological global management of nonfiber plastics waste, where an increase in recycling and incineration and a decline in landfilling over time can be seen. However, less than 10 percent of the 6,300 MMT of plastics cumulatively produced globally through 2015 had been recycled (Geyer et al. 2017). And only 14 to 18 percent of plastic packaging, the primary use of plastics, was recycled globally in 2018 (Mil- brandt et al. 2022). Of the recycled packaging material, approximately half is recycled to produce lower-quality materials or products than the origi- nals, and less than 15 percent resulted in closed-loop recycling3 (Li et al. 2022). Furthermore, plastic production and use has shifted to Asia (China, for example, produces 32 percent of global plastics [Statistica 2022]), where the waste management infrastructure is even more dependent on landfilling. In the United States, 27 MMT of plastics waste were landfilled, 5.6 tons incinerated, and 3.1 MMT recycled (9 percent) in 2018 (USEPA 2022). In 2021 it was estimated that the infrastructure for plastics waste man- agement requires an investment in the United States alone of US$17 billion over the following 5 years (The Recycling Partnership 2021) to reasonably manage recyclables. Recycling is an essential component of the circular economy, depicted in Figure 3-3. Some argue, however, that all plastic pro- duction and use is inherently noncircular, due to the presence of additives in plastics that end up as contaminants in recycled plastics and the difficulty and cost of recycling plastics (Greenpeace 2022). Environmental and Socioeconomic Considerations Plastics waste leaks4 from the waste management value chain at multiple points, primarily through littering and improper waste storage, collection, and disposal. OECD (2022) estimates the global plastic leakage at 22 MMT 3 Closed-loop recycling is defined as a process by which products are used, recycled, and manufactured into new products of the same quality (e.g., a waste plastic bottle is recycled and refabricated into a new plastic bottle). No waste products are produced through this process. On the other hand, open-loop recycling is the process in which the recycled material is turned into both new raw materials and waste products. 4 Plastics waste leakage refers to discarded plastics that escape the waste collection and management process.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 37 FIGURE 3-2 Historic global plastics waste disposal. SOURCE: Geyer 2020. FIGURE 3-3 Value streams in a circular economy. SOURCE: Presentation to the study committee by Rachel Meidl on August 31, 2022.

38 RECYCLED PLASTICS IN INFRASTRUCTURE in 2019, 82 percent of which was mismanaged waste. That value represents more than 5 percent of global plastics waste generated. Leakage causes aesthetic, ecosystem, and economic damage (NASEM 2022). Once in the environment, plastics may break down into microplastics and nanoplastics that further endanger both marine and terrestrial species. Avoiding mis- management of plastics waste will reduce environmental impacts and also help satisfy the growing demand for the limited supply of properly sourced recycled materials. PLASTICS RECYCLING IN THE UNITED STATES Sources of Plastics for Recycling For plastics waste to be diverted for reuse in infrastructure it must have the potential to be sourced and processed in sufficient volume and quality to be useful. Thermoplastics used for durable applications, such as polyvinyl chloride (PVC) sewer pipe and electric wire insulation and high-density polyethylene (HDPE) storm drainage pipe, rarely become municipal solid waste. Nondurables, with service lives lasting less than 3 years, are often recyclable, particularly polyethylene terephthalate (PET) and HDPE items, with the exception of multilayered plastic composite products, biomedical devices, and hard-to-recycle materials such as PVC and polystyrene (PS). Plastics waste is generated at multiple locations in the plastics produc- tion-and-use cycle, as illustrated in Figure 3-3. These include post-industrial wastes generated during production and post-consumer wastes generated after plastic product use. The methods for collection, quality, transport, and sorting vary significantly depending on the source, as detailed in Table 3-2. Post-industrial and post-consumer plastics waste management is described in more detail below. Post-Industrial Recycled Plastic Post-industrial recycled (PIR) plastic is scrap that is generated from a manu- facturing plant. The plant may choose to do in-house recycling, sell the scrap plastic, or partner with an external recycler. Post-industrial recycled plastic is relatively clean compared to post-consumer recycled plastic. No sorting is needed for PIR plastic. The plastic scrap type and quality are known and controllable, making the process of recycling back to a qual- ity plastic pellet relatively simple. Annual quantities of post-industrial (or “commercial”) sources in the United States were estimated by Meyer et al. (2020) and are provided in Table 3-3. PET, HDPE, and LDPE are the types of post-industrial plastic recycled in the greatest quantities.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 39 Post-Consumer Recyclables Residential post-consumer waste collection for recyclables in the United States is primarily accomplished by a network of 9,000 local recycling pro- grams. The post-consumer recyclables (PCR) stream represents the largest potential source of recycled plastic, although the collection and processing of residential waste streams has many challenges. Estimates of recovered PCR plastics in the United States are provided for 2010-2020 in Figure 3-4. As shown there, and as documented by others (e.g., Di et al. 2021), PET, HDPE, and LDPE are the types of post-consumer plastics recovered in the greatest quantities. TABLE 3-2 Differences in Management of Plastics Waste Among Sources Post-Industrial Waste Post-Consumer Commercial Waste Post-Consumer Household Waste Definition Waste generated during the manufacturing process. Waste generated by commercial, industrial, or institutional facilities. Waste generated by households as end users or a product. Example(s) Waste generated in plastic production and conversion. Waste packaging generated in the distribution chain or waste generated by consumers at a business’s premises. A used plastic yogurt pot or soft drink bottle. Collection Via negotiated contracts with waste management companies. Via negotiated contracts with waste management companies to collect high-volume containers. Municipalities are sometimes also involved in collecting this stream. Typically operated or subcontracted by municipalities. Collection through curbside and communal collection, deposit-refund schemes, and the informal sector. Municipalities are sometimes also involved in collecting this stream. Sorting Relatively homogeneous waste stream. If properly sorted at source, a homogenous waste stream can be achieved. Intensive sorting and separation required. Impurities often lead to downcycling. Transport/ Trade Tends to be processed domestically. Can be processed domestically or exported for recycling somewhere. Pure streams are domestically recycled but other streams may be exported for recycling. SOURCE: Adapted from OECD 2022.

40 RECYCLED PLASTICS IN INFRASTRUCTURE TABLE 3-3 Post-Industrial (Commercial) Plastics Waste/Scrap Annual Generation Rates in the United States (see Appendix E) Plastic Type Annual Commercial Generation (kt) Durable Plastic Items—Number 2 and 5 Bulky Rigids 411 Durable Plastic Items—Other 1,488 Film Products 67 HDPE Plastic Containers 787 Miscellaneous Plastic Containers 626 Non-Bag Commercial and Industrial Packaging Film 1,041 Other Film—Other 3,388 PETE Plastic Containers 1,070 Plastic Grocery and Other Merchandise Bags 318 Plastic Trash Bags 3,157 Total 12,353 NOTES: HDPE = high-density polyethylene; kt = 1,000 metric tons; PETE = polyethylene terephthalate. Commercial plastics waste generation as estimated by the authors from data in California’s commercial recycling survey (CalRecycle 2015) using an approach similar to that of Meyer et al. (2020). FIGURE 3-4 Post-consumer plastics recovered in the United States, 2010-2020. SOURCE: Stina 2021.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 41 PCR plastics collection is expensive and typically is the bottleneck for the plastics ecosystem. Post-consumer recycling requires three successes. First, there must be a supply of consistent material in enough quantity (referred to as “critical mass”) collected to make profitable enterprises. The actual entry of post-consumer material into the post-consumer recycle stream requires the effort of the public, either to take back containers to recover a deposit, place recyclables in a container at the curb, or place recyclables at a community drop-off center. A variety of sorting schemes have been tried, including householders sorting into as many as 12 or more collection containers (rarely used in the United States), sorting at the collec- tion truck (uneconomical) (Zbib and WØhlk 2019), dual stream collection (one bin for paper, a second bin for glass, plastic, and metal containers— partly successful), and single-stream collection (all recyclables at the curb in one bin) (Tonjes et al. 2018). The most common method employed in the United States, single-stream collection, leads to higher contamination levels, although it saves in collection costs. Mass sorting of all waste (recyclable and nonrecyclables) collected together at a central sorting plant historically has not been economically viable. Although recent advances in sorting tech- nology have improved the economics, contamination of separated material continues to be a challenge (Rogoff and Clark 2016). Commercial opera- tions need to take the collected material and make clean, usable plastic and do so at a profit. Third, some entity, perhaps the secondary or tertiary recy- cler, must make a profitable product for sale either as a recycled commodity feedstock for manufacturing or as a package or product for consumer use. It generally takes time for the market signals to go up and down the supply chain for post-consumer recycling, as the same entities are not positioned in all three areas of needed success: collection and sorting, processing, and reuse or remanufacturing. There are multiple collection approaches for PCR plastics waste, in- cluding drop-off, residential curbside, dumpsters at multifamily housing and commercial establishments, reverse vending machines, and buy-back centers. In some small-economy, poorer countries, the informal sector often collects plastics waste directly from disposal containers and land- fills, at great risk to their health (Li et al. 2022). Figure 3-5 provides an estimation of the distribution of access to various collection systems in the United States. Drop-off collection of recyclables is primarily used in either rural areas or areas with high traffic, such as city centers, for collection from individu- als without access to residential curbside collection systems. Few details on the effectiveness of drop-off collection are available; however, a study by Hahladakis et al. (2018) found that approximately 90 percent of plastic packaging was collected via curbside collection in the United Kingdom, as opposed to household waste recycling centers and “bring sites”/banks.

42 RECYCLED PLASTICS IN INFRASTRUCTURE FIGURE 3-5 Access to residential curbside recycling. SOURCE: The Recycling Partnership 2020. Plastics waste management is complicated by flexible, film plastics, which are among the most difficult plastics to collect and sort. Because they are so difficult to separate from other recyclables, most plastic films are not included in U.S. curbside collection, often making drop-off programs (commonly back-of-the-store collection) the only viable means to recover post-consumer LDPE and other hard-to-recycle plastics. In fact, less than 0.3 percent of post-consumer plastic film waste is collected (U.S. Plastic Pact 2020). Likewise, polystyrene is rarely accepted by PCR collection systems because it tends to be contaminated by food and drink and its low specific weight makes it costly to transport. Approximately 59 percent of U.S. residents, or 70 million single-family homes, have access to residential curbside collection (RCC) (The Recycling Partnership 2020), which collects approximately one-third of all U.S. recy- clables. Those without access are often in small rural communities. Partici- pation in RCC is considerably less than 100 percent; one estimate puts it at 72 percent on average (The Recycling Partnership 2021). Curbside capture rates of available materials are even lower; for HDPE bottles, the rate is 46 to 53 percent; for PET bottles, 40 percent; and for bulky rigid plastics, 22 percent. Table 3-4 provides an estimate for total amounts of recyclables collected via RCC systems in the United States in 2019 (The Recycling Partnership 2020). Waste generated by nonparticipating residents and the noncaptured materials frequently ends up being incinerated or landfilled and is lost to the circular economy.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 43 RCC is typically a service provided by municipalities, which shifts much of the cost of recycling away from producers. RCC is accomplished by waste collection vehicles, either maintained and operated by municipali- ties or contracted from private companies, serving single-family residences. In early U.S. municipal recycling programs of the 1980s and 1990s, recy- clables were either sorted at the curb manually and placed into multiple receptacles for separated waste streams or separated by the resident into multiple bins stored at the home. To simplify residential requirements, increase residential participation, and lower collection costs, most munici- palities in the United States moved to collection of recyclables as a single stream with separation at materials recovery facilities (MRFs), which re- duces time and expense of collection considerably (Tonjes et al. 2018). Trucks are driven along a residential street, stopping briefly to manually or TABLE 3-4 Estimate of Annual Tonnage of Residential Recycling Material Generation in the United States in 2019 Material Single-Family Generation (tons) Multifamily Generation (using 75% Single-Family Generation Factor) (tons) Total Residential (tons) Cardboard 5,196,756 841,076 6,036,831 Mixed Paper 14,722,469 2,383,236 17,105,704 Aseptics and Cartons 295,586 47,849 343,434 PET Bottles 2,478,193 401,164 2,879,356 No-Bottle PET 524,009 84,825 608,835 HDPE Natural Bottles and Jars 512,905 83,028 595,933 HDPE Colored Bottles and Jars 786,644 127,340 913,984 Glass Containers 7,613,441 1,232,444 8,845,885 Steel Cans 1,126,674 182,383 1,309,058 Aluminum Cans 1,002,515 162,285 1,164,800 Aluminum Foil and Trays 273,814 44,324 318,138 Other Plastic Packaging 1,671,402 270,400 1,940,803 Bulky Rigid Plastics 1,161,215 187,975 1,349,190 Total 37,363,623 6,048,328 43,411,951 NOTE: Because of data rounding, some total values may show a small discrepancy to the sum of presented data. SOURCE: The Recycling Partnership 2020.

44 RECYCLED PLASTICS IN INFRASTRUCTURE automatically (using a mechanical arm) pick up containers and empty them into the truck. The truck continues along the collection route until it is full or has reached the legal weight limit. It is then driven to a transfer station or to an MRF. At a transfer station, recyclables are placed in larger trucks and transported to an MRF. Some trucks can compact the recyclables, which reduces collection costs but at the expense of the quality of the collected material. Nonrecyclables are often also placed in the recycling bin, which reduces the value of recovered materials and efficiency of separation. Plastic post-consumer waste is highly heterogeneous and may be com- posed of multiple types of plastics, either mixed or as multilayer products. In addition, plastics can be contaminated by other materials, such as food or liquids. Lange (2021) reported that separated plastic may consist of 5 to 15 percent foreign plastics and paper and an equal amount of residue. This contamination significantly reduces the value of the recovered plastic. Waste collection typically represents the largest fraction of the waste man- agement costs, as it is energy-intensive, relies on manual labor, and uses high-maintenance vehicles (Vesilind and Reinhart 2002). Materials Recovery Facility Collected recyclables are taken to an MRF for sorting and preparation for shipment. There are multiple types of MRFs depending on the type of waste managed, including dirty MRFs (mixed-waste processing), single-stream MRFs, dual-stream MRFs, and source-separated MRFs. In the early days of PCR, human sorters at the MRF picked items from a slow-moving con- veyor belt. Today, human sorters are needed for almost all MRF types to remove grossly inappropriate items, and separation technologies are used to remove desired materials. Sorting the paper and cardboard from contain- ers starts with various devices that focus on separating two-dimensional paper from three-dimensional containers. Plastic films and pouches, which are not sought after for MRF sorting, often follow the paper, as they are a contaminant to paper and cardboard recyclables. Films and bags, if present, must be removed by people or robots. Other plastic materials are separated by mechanical/physical means, with different technologies employed for different types of plastics (e.g., infrared light scanning to identify targeted materials like PET, HDPE, and polypropylene [PP] with high-speed eject sorting or lower-speed robotic sorting). Depending on the capital available, other technologies may be employed to remove contaminating material. The final step is to bale separated plastic materials for shipment. Bales are wrapped with galvanized wire and stored out of sunlight before shipment to secondary recyclers. Acceptable levels and types of contamination along with pricing are negotiated between buyer and seller. The Association of Plastic Recyclers (APR) and the Institute of Scrap Recycling Industries

MANAGEMENT AND SOURCING OF PLASTICS WASTE 45 (ISRI) have developed specifications for plastic bales intended to facilitate sales (APR 2022b; ISRI 2022). MRFs play an important role in successfully recycling plastics but typically require financial subsidies to operate (Rafter 2016).5 Financial incentives encourage the efficient operation of MRFs and reduce adverse impacts of local and state policies and variability in recycled commodity market values that can reduce the supply of recyclables. Landfilling of recy- clable materials is generally the less expensive management route; therefore, cost and revenue sharing may be important to maintaining MRF financial stability (RRS 2022). For example, California compensates MRFs for lost revenue that results from the implementation of container deposit programs (RRS 2022). Efforts to ensure the high quality of collected materials, per- haps through revenue sharing, may also increase the probability of MRF success. Public and private investments in technology to improve sorting and processing, create new markets for recycled materials, and modernize data-processing capabilities are also important. TYPES OF RECYCLED PLASTICS PROCESSING Once collected, processed, and delivered to the recycler the actual process of preparing the plastics waste for future use begins. Plastic secondary re- cycling (also referred to as reuse or remanufacturing) involves mechanical processing, wherein the original polymer composition is retained, and poly- mer molecular weight is not intentionally lowered. Tertiary, or chemical, re- cycling is when the polymer chains of the macromolecules are intentionally shortened. Figure 3-6 provides an overview of the various recycling meth- ods currently available. Mechanical recycling can return a plastic product suitable either for the initial use, including food and beverage containers, or for another use. The other use may be higher value than packaging or be the highest-value use for the quality of the recycled plastic. The technologies used in chemical recycling generally are not new, but some of them are seeing growing interest and investment (Tullo 2022a, 2022b, 2022c, 2022d, 2022e). Progress in their use in plastics recycling has been slow. The U.S. Government Accountability Office (GAO) reports that the slow introduction of chemical recycling is due to several factors: low cost of virgin plastic material, challenges with recycling complex and contaminated plastic products, and high startup and operating costs for facilities (GAO 2021). Currently, chemical recycling is usually preceded by mechanical processing of some form, as pretreatment to increase purity of feedstock (Tullo 2022c). 5 According to Greenpeace (2022) there are approximately 375 MRFs in the United States; USEPA, however, reported a total number of 532 in 2018 (USEPA 2020).

46 RECYCLED PLASTICS IN INFRASTRUCTURE Driven by the declining acceptance by other countries of plastics waste exports from the United States, the number of recycling facilities in the United States is increasing. Li et al. (2022) reported that there are approxi- mately 115 PET and 40 polyethylene recycling facilities in the United States; these are almost exclusively mechanical recyclers. Mechanical Recycling Mechanical post-consumer rigid plastic bottle recycling has been the prov- ince of the commercial sector. Today, some are connected to bottle makers, FIGURE 3-6 Recycling methods currently available. SOURCE: Li et al. 2022.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 47 some to plastics manufacturing companies, some to HDPE pipe makers, and some to PET carpet makers, and some are strictly merchant pellet sell- ers (Li et al. 2022). Capacities smaller than about 20 million annual pounds of used bottles processed result in relatively high fixed cost. Capacities more than 200 million pounds are unusual at present. Typically, baled PCR plastic is sold to recyclers by the MRF operators. Mechanical processing of plastic bales involves a series of unit operations (Schyns and Shaver 2020). At the secondary recyclers, trailers arriving with baled plastic are unloaded either to storage (best in a sun-protected warehouse) or to the operating floor, where the first quality control obser- vation is made. Bale wires are cut and the bales are loaded into a trommel (a rotating cylinder with holes, for the removal of stones, broken glass, and small plastic pieces). Thereafter, several unit operations are common, although not every operation is conducted by every recycler, and not neces- sarily in this order. The de-baled plastic is stripped of steel by magnets and of aluminum by eddy current repulsion units, de-labeled, and washed at 40°C to 80°C in aqueous solutions of sodium hydroxide and/or surfactants and defoamers. The washed plastics are rinsed and drained. The bottles are separated by color in a near-infrared (NIR) optical sorter. The sorted plastic articles are chopped into flakes about 1 cm square; this is referred to as wet grind. Dry grind, conversely, has both labeled and de-labeled bottles sorted with the NIR autosorter; ferrous metal is removed, ground, elutriated (i.e., separated by varying bulk density), and washed. The washed flakes are spun dry. Dry flakes are elutriated to remove residual label, paper, and plastic dust. A flake sorter may be used to remove contamination. The flakes are then melted and pellets formed. Flakes or pellets may be subject to intense drying or solid-state polymerization conditions to satisfy the U.S. Food and Drug Administration (FDA) No Objection Letter requirements for use in food contact (ECCC 2021). Pellets are then combined with virgin plastics and additives and formed by either extrusion, injection molding, or blow molding. Figure 3-7 provides a simplified schematic of the processes described above. Films can be processed dry with chopping, wind sifting, densification, and pelletization. Inherently clean films are needed. Washing film is more complicated than washing bottles. Rinsing and drying films efficiently is complex. As Chapters 6 and 7 discuss, the acceptance of recycled plastics for use in infrastructure materials and products depends heavily on their quality and cleanliness. These requirements impact the source (e.g., post- industrial versus post-consumer) and the quantity of plastic films that can be recycled for uses in infrastructure applications. Nonetheless, dirty films, depending on the level of contamination, can be recycled and used for plastic lumber.

48 RECYCLED PLASTICS IN INFRASTRUCTURE Chemical Recycling Chemical recycling of plastics involves breaking down plastics into molecu- lar building blocks (depolymerization) for remanufacturing and reuse. The techniques used depend on the chemistry of the plastics. Much of the focus to date has been on PET, but research and development for other types of plastics is in progress (Li et al. 2022). Condensation polymers, like PET, can be reacted with the reverse of the polymerization reaction. Excess hydroxyl (–OH)-bearing reactant (eth- ylene glycol, methanol, or water) is reacted with PET material to recreate the monomers used to form the polymer originally (bis-2-hydroxyethyl terephthalate [BHET] for ethylene glycol, dimethyl terephthalate [DMT] and ethylene glycol for methanol, and terephthalic acid and ethylene gly- col for water). A summary of the process is provided in Figure 3-8. The monomers still must be purified before repolymerization. The processes require high temperature (i.e., 100°C to 300°C) and, in some cases, high pressure. Extensive research and development have been conducted on these processes, and there is substantial patent history (Li et al. 2022). There are some small-scale, niche, commercial successes of chemical recycling. For example, DMT has a history of chemical recycling such as the process FIGURE 3-7 Schematic of mechanical recycling process and new product development. SOURCE: Li et al. 2022.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 49 used by Eastman Kodak Company for the recovery of DMT from used x- ray films. However, PET chemical recycling is not yet economical at large scales (Li et al. 2022). Dissolution-Based Plastics Recycling Dissolution approaches employ solvents to extract plastic compounds without chemically modifying their structures (Li et al. 2022). The target polymer is selectively dissolved in a solvent or solvent mixture at a selected temperature, the solid material is separated from the solvent by filtration, and the polymer is then precipitated from the solvent by addition of a re- agent or adjustment of temperature. Dissolution-based approaches have the potential to yield high-quality polymers for reuse (Li et al. 2022), do not involve use of high temperatures and pressures, and have lower emissions profiles than other technologies. There are commercial technologies in de- velopment and some demonstration plants have been constructed (Li et al. 2022). Some would consider these approaches a form of chemical recycling. Thermal Decomposition of Plastics: Pyrolysis Pyrolysis is the thermal destruction of the plastic molecule with a variable slate of reaction products in an inert (oxygen-deficient) atmosphere (Li et al. 2022). The resulting mixture of smaller-molecule products is known as FIGURE 3-8 Strategies for PET chemical recycling. NOTE: BDM = benzenedimethanol; BHET= bis-2-hydroxyethyl terephthalate; DET = diethyl terephthalate; DMT = dimethyl terephthalate; EG = ethylene glycol; MHET = mono-2-hydroxyethyl terephthalate; TPA = terephthalic acid. SOURCE: Li et al. 2022.

50 RECYCLED PLASTICS IN INFRASTRUCTURE “pyrolysis oil,” which can be further processed to yield useful liquids such as naptha and diesel (Tullo 2022c). Thermal pyrolysis operates at a high temperature (~400°C to 500°C), using product gas as fuel. Pyrolysis can be catalytic and operate at lower temperature (~300°C) with a more specific slate of products, but the catalyst is subject to deactivation. There is a sig- nificant amount of commercial development of pyrolysis technologies for processing of plastics waste (Hogue 2022a; Li et al. 2022; Tullo 2022c). Approaches for overcoming various challenges, such as dealing with vari- able plastics waste feedstock, which results in product variability, are being developed. However, as discussed in Box 3-1, there is lack of consensus, and even some controversy, about whether pyrolysis should be considered recycling (Hogue 2022a, 2022b; Tullo 2022c). BOX 3-1 Pyrolysis and Plastics Recycling Interest in pyrolysis by the petrochemical industry as a means of managing plastics waste has been increasing in the United States and globally under in- creasing public pressure for more collection and reuse of plastics (Hogue 2022a; Tullo 2022a, 2022b, 2022c, 2022d). A range of pyrolysis technologies are in development, with some technologies sufficiently advanced to be commercially viable at scale (Hogue 2022a; Tullo 2022c). The American Chemistry Council, a prominent trade association for the chemical industry, refers to pyrolysis tech- nologies as among a group of “advanced recycling technologies” for plastics and advocates for state and federal policies that support these technologies for recycling (ACC 2022). As of 2022, 18 states had passed legislation that encourages advanced recycling technologies for plastics (Hogue 2022a). Many groups and some states, however, do not consider technologies employing high- temperature and high-pressure processes for the decomposition of plastics to constitute recycling. Their position is that these processes are energy-intensive, generate significant emissions, and produce fuels and should be considered manufacturing and not recycling (Hogue 2022a). The counterargument is that these are recycling processes in that they take in plastics waste and yield an end product with higher market value (Hogue 2022a). In 2022, the State of California included in plastics recycling legislation a prohibition from considering plastic decomposition processes as recycling (Hogue 2022b). Laws passed in Arkan- sas and Kentucky do not allow fuel production from plastics to be considered recycling, though legislation in other states specifically includes such processes in their definitions of recycling (Hogue 2022a). At the federal level, the U.S. Environmental Protection Agency is considering industry requests to not require plastics waste pyrolysis and gasification units to meet air emissions requirements as stringent as those required for incinerators combusting solid waste under the Clean Air Act (Hogue 2022a). Thus, the status of pyrolysis as a recycling technol- ogy is variable, uncertain, and evolving.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 51 Liquefaction of Plastics Liquefaction involves the conversion of plastic feedstock material under high temperatures (200°C to 450°C) and pressure into an oil in the liquid phase (Li et al. 2022). When a solvent is employed, the process is called solvent liquefaction. Solvents used include hydrocarbons, alcohols, and water. Super- critical conditions are often used in liquefaction processes to increase reaction rates and the solubility of reaction products. There has been substantial re- search and development with regard to liquefaction, including the construc- tion and operation of demonstration facilities in Germany and Japan, but processes are expensive and not economically viable (Li et al. 2022). As with pyrolysis, many do not consider liquefaction to qualify as recycling. Gasification of Plastics Gasification involves oxidative conversion of solid plastic materials to gas at high temperature (>550°C) in the presence of oxygen or air (Li et al. 2022). “Producer gas” (CO, H2, CH4) is yielded when air is used, while “synthesis gas” (CO, H2) is yielded when oxygen is used for the gasifica- tion. These gases can be combusted for energy production or used to make larger molecules. Gasification usually is done on size-reduced plastics waste material, not whole bottles. Gasification technology is at a mature state of development and employed for municipal solid waste, coal, and other organic materials (Li et al. 2022). The technology has been demonstrated at scale but is expensive to construct and operate. As with pyrolysis, many do not consider gasification to qualify as recycling. HISTORY OF RECYCLING IN THE UNITED STATES Post-industrial plastics involve capture and reuse of plastic scrap generated in the manufacturing of plastic materials. During the extruding process, manufacturing requires trimming the edges of the product that is being produced; the trimmings become scrap. Because of the scrap generated from the trimming process, typically, the productive use of prime plastic material ranges from about 70 percent to above 90 percent, depending on the products being manufactured. Manufacturers—in particular, fabricators producing “low-yield” products—have regularly tried to recycle and reuse the trimmed plastic scrap within their own operations whenever possible. Over the years a robust secondary materials market arose with well-devel- oped markets for post-industrial plastics. Post-consumer plastics recycling became an economic reality with the bottle deposit laws passed in the United States for carbonated beverages packaged in PET bottles, starting with the first such law in 1971 in Oregon

52 RECYCLED PLASTICS IN INFRASTRUCTURE (Bottle Bill Resource Guide 2022). The beverage bottle and can deposit laws were passed as antilitter laws. In the earliest days, the collected materials were baled and landfilled, although this is no longer the case. The deposit laws for plastic bottles applied almost exclusively to PET. With more than 40 percent of PET collected coming today from deposit system collection, critical mass was achieved in the late 1970s and collection was a success (Forrest 2019). PET is used for four major areas of applica- tion: fiber (cotton-simulating staple and filament), bottles, flat film (used in the 1970s for x-rays and graphic arts; today, also for thermoformed packag- ing), and strapping. PET is not generally a good injection-molding material. Assured of supply from New England states’ deposit laws, several entre- preneurial small businesses took on the task of processing baled PET bottles to PET pellets and HDPE pellets. These included St. Jude Polymer (later sold to ITW), Nyconn Industries (closed), and Star Plastics (later renamed WTE, now UltrePET, LLC). These companies, all small at inception, sold pellets to others, primarily staple fiber and strapping makers. Larger companies, Wellman (sold fiber) and Image Carpet (selling carpet to consumers), also got into bottle recycling, generally for inexpensive raw material. Carpet fiber with high denier6 proved to be an ideal use for recycled PET. A few bottle makers tried to be bottle reclaimers; only one succeeded, Plastipak, initially making bottles for nonfood household chemical (detergent, window cleaner) and later for food. The motivation was economic, not to meet mandates. A range of technologies was tried: cotton ginning–like technologies in the South, seed-sorting technologies in the Midwest, and froth flotation in the West. Goodyear Tire and Rubber, the early leader in making PET for bottles (bottles needed higher Intrinsic Viscosity [IV] [a measure of polymer molecu- lar weight] than staple fiber, and Goodyear made high-IV tire cord), devel- oped a continuous pilot plant that the company gave to Rutgers University when Goodyear decided they did not want to be in the recycling business, which formed the model for the industry. The early processing lines were created by the entrepreneurs; later, equipment suppliers offered complete processing lines. Over the early years, many chemical companies including Dupont, Hoechst-Celanese, and Dow Chemical investigated PET recycling and decided the opportunity did not meet their goals. While PET recycling was kickstarted by the bottle deposit public policy, rigid-bottle HDPE recycling got its boost from California’s Rigid Plastic Packaging Container Act of 1991 (CalRecycle 2022), which required 25 percent post-consumer recycled content in nonfood bottles and nonmedi- cal bottles. By 1991 there were curbside collection programs supplying raw material. After 1991 there was a mandated use for such as containers for detergent, laundry bleach, and fabric softeners. 6 Denier is a weight unit for continuous filament yarn. One denier is equivalent to 1 gram of mass per 9,000 meters of length of filament.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 53 Again, the reclaimers were entrepreneurs like Talco Plastics, Envision Plastics (now owned by Altium Packaging), and KW Plastics (which started recycling polypropylene battery cases in 1981). The synthesis companies investigated and backed away, including Union Carbide, who sold technol- ogy to Envision. FDA and Post-Consumer Plastic Recycling Closed-loop recycling returns a discarded item to the same application. Plastics are frequently used in food packaging, medical devices, and phar- maceuticals. FDA regulates the inclusion of recycled plastics and requires all products that come into contact with food to undergo safety testing (Sorensen et al. 2022). For food and beverage packaging (other than that for milk, which is regulated by the U.S. Department of Agriculture), post- consumer recycled plastic must have an FDA “No Objection Letter” (NOL), which states the limitations of use of recycled plastic for food use. No Ob- jection Letters, also called “Letters of No Objection,” are issued on petition and review by FDA. As of June 2022, 271 NOLs have been issued: 194 for PET, 34 for HDPE, six for LDPE, two for LLDPE, 22 for polypropylene, and 23 for polystyrene, which received the first NOL in February 1990 for egg cartons (FDA 2022). Petitioners may be processors of post-consumer plastic, brand companies, testing laboratories, machinery makers, or others. FDA requires that the polymer and any additive be “food grade” and regulated. All PET polymer, as created, is food grade. Polyethylene and polypropylene usually require stabilizers for nonfood use and cannot be used for food. Many states are requiring or considering a minimum content of recycled plastics in food packaging. This creates a high demand for food-grade PCR; however, multiple challenges exist (ECCC 2021). For example, the recycled product may not have been originally produced with food-grade plastics. Furthermore, plastic additives (e.g., metal-based colorants) or contaminants leached from packaged products that are not removed during PCR plastic processing may not be safe for consumers. Manufacturers report that use of PCR in food-grade applications requires confidence in the source of the material; clean sources are in short supply (ECCC 2021). Consequently, no food-grade HDPE, LDPE, or LLDPE PCR films are presently recycled in Canada or the United States. Drivers As discussed further in Chapter 5, public policy has driven post-consumer plastics recycling. Consumers asking for recycling collection services have been important, and their participation is key to growth. It has been small business entrepreneurs who have raised the money and built the plants, sometimes with help from state grants.

54 RECYCLED PLASTICS IN INFRASTRUCTURE Decision making regarding virgin plastic versus recycled plastic mar- kets is influenced by a number of factors. When crude oil and natural gas prices are low, virgin petrochemical-derived plastic can be less expensive than recycled plastic, depending on market dynamics for both virgin plastic and plastics waste. Crude oil is not as significant an economic cost driver for post-consumer recycling as it is for production of petrochemical-de- rived plastics. The desire for diverse feedstock sources is also a factor that drives demand and price for recycled plastic, as manufacturers navigate the dynamic market for virgin and recycled plastics. Local landfill disposal availability and pricing can also influence availability of plastics waste for recycling. It is often cheaper to dispose of plastics waste than to recycle it (ECCC 2021). Post-Consumer Plastic Recycling Challenges There are many challenges associated with collecting and processing these materials. These challenges have led to an imbalance of supply and demand, discussed further below. Table 3-5 provides a summary of recycling poten- tial and challenges for each of the main types of post-consumer plastics that are typically available. Generally, recycling is limited by the large number of plastic types and formulations, the high cost of collecting and sorting plastics waste, and the cost and technical challenges of efficiently processing plastics waste (Li et al. 2022). PCR plastics are problematic to collect and process because they tend to be lightweight and bulky. The wide variety of polymers leads to consumer confusion over what to recycle, although label- ing systems such as How2Recycle promise to provide clarity (How2Recycle 2023). Concerns over contamination have kept the recyclable content low in food containers. The price of PCR plastics is not only a function of the current price of virgin plastic primary polymers, but also of the quality of the plastics waste, costs of alternative waste management approaches, and manufacturing costs for products using the recovered materials (OECD 2022). Note that 100 percent recyclability of plastic is unachievable due to complex product design, use of plastics for durable functions, concerns with plastics waste from medical use, unfavorable economics, and collec- tion/sorting restrictions (Greenpeace 2022; Hopewell et al. 2002; Tyler Packaging 2021). Furthermore, plastic quality declines during processing as a result of chain degradation from thermooxidation and impurities. For example, contamination by other plastics can accelerate PET acidolysis or hydrolysis. Quality degradation can impact flow and mechanical properties of the recycled material, impairing its use or creating a need for the addition of virgin plastics or additives (Li et al. 2022). Collection and processing of materials for recycling is an economic burden to many communities, subject to the inelasticity of the collected sup- ply to uncertain market forces. Local, national, and international policies,

MANAGEMENT AND SOURCING OF PLASTICS WASTE 55 TABLE 3-5 Post-Consumer Plastics Waste Recycling Potential and Challenges by Type Plastic Type Recyclable Plastic Packaging,a Globally Amount of Plastic Type Recycled in United States (%) Recycling Challenges Potential Recycling Markets PET 72% of PET bottles 15 Lack of supply, contamination, consumer confusion, product degradation, additives, and multiple PET manufacturing processes create products that cannot be recycled together. Bottle, fibers for carpet. HDPE 47% of HDPE bottles 10 Lack of supply, contamination, consumer confusion, additives, difficulty in mixing resins, and product degradation. Plastic storage containers, plastic lumber, plastic outdoor patio furniture, plastic playground equipment, plastic automobile parts, plastic trash cans, compost bins, recycling bins, and pipes. PVC 0% 3 Toxic materials can be released during processing. PVC pipes, garden hoses, mud flaps, and traffic cones. LDPE 0% 2 Lack of supply, multilayer applications that have chemically incompatible plastic layers that are very hard to separate, fouling of mechanical separation devices at MRFs. Film, sheeting, shipping bags, lumber, pipes, and traffic cones. PP 66% of PP bottles 3 Lack of supply, difficult and expensive to remove the smell of the product, additives. Food storage containers, bags, and gardening supplies, clothing, bags, and dishware. PS 0% 1 Lack of supply, contamination by food and drink; low specific weight makes it costly to transport. Packing and thermal insulation. a The U.S. Plastic Pact defines recyclable as follows: “A packaging or packaging component is recyclable if its successful postconsumer collection, sorting, and recycling is proven to work in practice and at scale and if the outcome of its processing via recycling is a specification-grade commodity for which a market exists.” SOURCES: Created with data from U.S. Plastic Pact (2020) and Milbrandt et al. (2022).

56 RECYCLED PLASTICS IN INFRASTRUCTURE such as China’s National Sword Policy that went into effect in 2018, can impact markets significantly (see Appendix E). Low participation rates and contamination issues also reduce the availability and value of collected materials considerably. Complexity in product design, particularly multi- layer products, also complicates the ability to separate plastics and ensure maximum value. The cost of recycling post-consumer plastic is sometimes greater than landfilling or incinerating recyclables for many communities, although the environmental benefits generally outweigh the environmental cost of other waste management approaches (ECCC 2021). Multiple life-cycle analyses (LCAs) have been performed on plastics waste recycling and disposal approaches. Li et al. (2022) summarized these publications and provided the following conclusions: (1) incineration has the highest greenhouse gas (GHG) emissions, and mechanical recycling had lower GHG emissions than chemical recycling; (2) chemical recycling has high acidification potential; (3) incineration has the highest air pollu- tion potential, mechanical recycling the lowest; and (4) regarding resource depletion, incineration and landfilling lose all raw materials used in plastic production, and mechanical recycling has the lowest resource consumption. From the LCAs reviewed by Li et al. (2022), it is apparent that the various methods of managing plastics waste have different environmental impact implications. The use of life-cycle analysis in evaluating options for plastics waste management is examined further in Chapter 4. RECYCLED PLASTICS SUPPLY AND DEMAND IN THE UNITED STATES While recycling plastics has benefits as well as costs, as previously dis- cussed, the multiple challenges with collecting, separating, and processing for upscaling, downscaling, or reuse result in a serious misalignment of material that can be supplied through recycling and total demand for plastic types, as seen in Figure 3-9. This figure compares availability of recycled material to plastic sales (i.e., total demand for plastic, not specifically de- mand for recycled material). Only limited data are available for recycled materials demand. As an example, a recent study found that there is an annual gap of more than 1 billion pounds between current U.S. supply and projected 2025 demand for recycled PET for use in bottles (The Recycling Partnership 2020). This imbalance is exacerbated by changing oil and natural gas prices (virgin plastic feedstocks) and also by evolving policy at all government levels, making demand predictions difficult. In addition, many companies are in- dependently setting ambitious goals for recycling content both for altruistic reasons and to ward off government mandates. A New Plastics Economy Global commitment (UNEP 2018) to increase post-consumer recyclable

MANAGEMENT AND SOURCING OF PLASTICS WASTE 57 content is expected to drive the global demand for recycled plastic to 5.3 million metric tonnes, which is around 20 percent of global packaging vol- umes. However, recycling capacity is much higher than currently utilized in the United States. A recent APR report (2022a) found that around 80 percent of the plastics recycled are PET, HDPE, and PP (averaging a 21 percent recycling rate), whereas the processing capacity is actually closer to 42 percent for these plastic types. The imbalance in supply and demand will continue into at least the near future. ReportLinker projects that, between 2020 and 2027, global demand for plastics recycling will grow at a compound annual growth rate of 6.1 percent (ReportLinker 2022). The private sector is responding to the increasing demand for recycled plastic. Republic Services, Inc., for example, recently announced a plan to develop an integrated process for collection and provision of high-quality materials for consumer packaging (Republic Services 2022). Also, the HDPE stormwater pipe manufacturer Advanced Drainage Systems (ADS) has developed and is expanding their own national network of plastics waste suppliers.7 7 Presentation to study committee by Daniel Figola and Greg Bohn on June 9, 2022. FIGURE 3-9 Comparison of U.S. plastics waste, recycled plastics by type, and total plastic sales and captive use (2020). NOTES: Data for percentage of recycled plastic from Milbrandt et al. (2022). PET sales data were not available. Percentage of demand calculated using U.S. plastic sales and captive use by resin, 2020 (Statista 2023). 0 2 4 6 8 10 12 14 16 PET HDPE PVC LDPE/LLDPE PP PS Pl as tic , m t U.S. Plastic Sales U.S. Waste U.S. Recycling

58 RECYCLED PLASTICS IN INFRASTRUCTURE Increasing demand versus supply has also led to price fluctuations and increases, as seen in Figure 3-10, which shows unit weight prices of recy- clable containers made of different materials including PET and HDPE. Supply and demand forces for post-consumer recyclables are unlike those for most commodities because of the disconnect between the value of the recycled material and the reward for recycling. Although demand for recyclables increases their price, consumers rarely see direct, personal monetary return for recycling today. Increasing supply requires actions that incentivize customers. Bottle bills and payback centers are examples of such incentives that have successfully increased recycling rates, as discussed in Chapter 5. Another potential path to increased supply is product redesign and simplification as discussed in Chapter 8. As seen in Figure 3-11, many types of plastic are not currently accepted at U.S. MRFs. The Association of Plastic Recyclers (APR 2022a) recommends the fol- lowing to increase the supply of post-consumer recyclables: • Ensure that new products are compatible with recycling, • Improve labeling to minimize consumer confusion about recycling, • Harmonize plastic resin types to minimize the number collected, • Invest in collection and sorting infrastructure, and • Increase the demand for recyclable plastics, which will serve as a driver for recycling. FIGURE 3-10 Five-year pricing trend for recyclable container commodities. SOURCE: NCDEQ 2022.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 59 Demand for recycled plastics has been increasing because of public interest in reducing plastics waste in the ocean (e.g., NASEM 2022) and other waterways, and in reducing plastic going to landfills (e.g., Greenpeace 2022). The increasing demand has led industry to form partnerships with entities with access to recyclables. It is important to continue to increase demand by identifying new markets or increasing recyclable content, but supply must also increase to reduce competition for the same source of recyclable materials. In the near term, balancing supply and demand will work best for industries where recyclable use is approximately equal to the supply of recyclables and for those that can tolerate contamination. For example, FIGURE 3-11 Single-use plastic acceptance in U.S. MRFs. NOTE: Data from 375 residential MRFs (Greenpeace 2022). SOURCE: Last Beach Cleanup 2023.

60 RECYCLED PLASTICS IN INFRASTRUCTURE color additives reduce the value of HDPE and the extent to which it can be recycled (in 2021 bale prices for natural recycled HDPE were almost twice that of colored HDPE; Ravi et al. [see Appendix E]). Black HDPE can be used for corrugated stormwater pipes, and the plastic stormwater pipe industry has developed its own supply chain. However, the demand from stormwater piping manufacturers is only a fraction of the production and use of black HDPE. FINDINGS • The portion of the plastics waste stream recycled in the United States is low—less than 10 percent. • PET, HDPE, and LDPE are the most recycled plastics in the United States. • The demand for high-quality plastics waste exceeds the supply. There are many competing uses for plastics waste. For example, the most collected and recycled plastics from waste streams—PET, HDPE, and LDPE—have many competing, noninfrastructure uses, such as bottles, carpet, and clothing. • Mechanical processing is the dominant approach for recycling of plastics. • Thermal technologies (including pyrolysis, liquefaction, and gas- ification) are in development. Pyrolysis and gasification have been demonstrated at scale for plastics waste management and are com- ing into commercial use. • Chemical recycling technologies, such as pyrolysis, are generally mature. However, their use in plastics recycling is still nascent. While the use of chemical recycling is seeing growing interest and invest- ment, historic barriers for adoption have been low cost of virgin plastic material, challenges with recycling complex and contami- nated plastics products, and high facility startup and operating costs. • Plastic recycling practices are highly variable across the United States. • States have different definitions of what plastics waste management processes constitute recycling. Use of plastics in infrastructure may or may not meet the definition of recycling for a particular state. There are different state policy positions about whether thermal technologies can be considered recycling. • There is significant variation across the United States and globally in the efficiency of plastics recycling. • Current plastics processing capacity of recycling plants in the United States is underutilized, exceeding the current collection and supply of plastics waste.

MANAGEMENT AND SOURCING OF PLASTICS WASTE 61 • Impediments and challenges to plastics collection and recycling ex- ist and limit the supply of recycled plastics for remanufacturing or reuse. For example, access to supplies of recycled plastics that have consistent quality can be problematic owing to the post-consumer collection process that is not standardized and often single stream, leading to contamination that can require additional processing. Supplies are further hindered by the absence of market-driven processes that encourage plastics waste collection and processing in the United States. REFERENCES American Chemistry Council (ACC). 2022. America’s Plastic Makers Encourage Congressio- nal Focus on Advanced Recycling to Achieve Circularity. https://www.americanchemistry. com/chemistry-in-america/news-trends/press-release/2022/america-s-plastic-makers-en- courage-congressional-focus-on-advanced-recycling-to-achieve-circularity Association of Plastic Recyclers (APR). 2022a. Recommit, Reimagine, Rework Recycling. https://plasticsrecycling.org/images/library/APR-Report-Recommit-Reimagine-and- Rework-Recycling-2022-8-9.pdf ——. 2022b. Model Bale Specifications. https://plasticsrecycling.org/model-bale-specifications Bottle Bill Resource Guide. 2022. What Is a Bottle Bill? https://www.bottlebill.org/index.php/ about-bottle-bills/what-is-a-bottle-bill CalRecycle. 2015. 2014 Generator-Based Characterization of Commercial Sector Disposal and Diversion in California. https://www2.calrecycle.ca.gov/WasteCharacterization/ PubExtracts/2014/GenSummary.pdf ——. 2022. California’s Rigid Plastic Packaging Container (RPPC) Program. https://cal recycle.ca.gov/Plastics/RPPC Di, J., Reck, B. K., Miatto, A., and Graedel, T. E. 2021. United States plastics: Large flows, short lifetimes, and negligible recycling. Resources, Conservation & Recycling 167:105440. Environment and Climate Change Canada (ECCC). 2021. Assessing the State of Food Grade Recycled Resin in Canada & the United States. https://www.plasticsmarkets.org/jsf content/ECCC_Food_Grade_Report_Oct_2021_jsf_1.pdf Forrest, M.J. 2019. Recycling of Polyethylene Terephthalate. Berlin, Boston: De Gruyter. https://doi.org/10.1515/9783110640304 Geyer, R. 2020. Chapter 2: Production, use, and fate of synthetic polymers. in Plastic Waste and Recycling, edited by T. M. Letcher. New York: Academic Press, pp. 13-32. Geyer, R., Jambeck, J., and Law, K. L. 2017. Production, use, and fate of all plastics ever made. Science Advances 3(7). https://www.science.org/doi/full/10.1126/sciadv.1700782 Greenpeace. 2022. Circular Claims Fall Flat Again: 2022 Update. https://www.greenpeace.org/ usa/reports/circular-claims-fall-flat-again Hahladakis, J. N., Purnell, P., Iacovidou, E., Velis, C. A., and Atseyinku, M. 2018. Post- consumer plastic packaging waste in England: Assessing the yield of multiple collection- recycling schemes. Waste Management 75:149-159. Hogue, C. 2022a. What is recycling? Chemical & Engineering News May 16:25. ——. 2022b. California mandates plastics recycling. Chemical & Engineering News, July 11/18:17. Hopewell, J., Dvorak, R., and Kosior, E. 2009. Plastics recycling: Challenges and opportunities. Philosophical Transactions of the Royal Society B: Biological Science 364(1526):2115- 2126. https://doi.org/10.1098/rstb.2008.0311

62 RECYCLED PLASTICS IN INFRASTRUCTURE How2Recycle. 2023. Our Mission. https://how2recycle.info/about Institute of Scrap Recycling Industries (ISRI). 2022. ISRI and APR Release Updated Recycled Plastics Specifications. https://www.isri.org/news-publications/news-details/2022/09/20/ isri-and-apr-release-updated-recycled-plastics-specifications Lange, J. P. 2021. Managing plastics waste-sorting, recycling, disposal, and product redesign. ACS Sustainable Chemistry & Engineering 9(47):15722-15738. https://doi.org/10.1021/ acssuschemeng.1c05013 Last Beach Cleanup. 2023. 2022 U.S. Post-Consumer Plastic Recycling Survey. https://www. lastbeachcleanup.org/2022usplasticsrecyclingsurvey Law, K. L., Starr, N., Siegler, T., Jambeck, J., Mallos, N., and Leonard, G. 2020. The United States’ contribution of plastic waste to land and ocean. Science Advances 6(44). Li, H., Aguirre-Villegas, H., Allen, R., Bai, X., Benson, C., Beckham, G., Bradshaw, S., Brown, J., Brown, R., Sanchez Castillo, M., Sanfins Cecon, V., Curley, J., Curtzwiler, G., Dong, S., Gaddameedi, S., Garcia, J., Hermans, I., Kim, M., Ma, J., and Huber, G. 2022. Expanding plastics recycling technologies: Chemical aspects. Technology status and challenges. Green Chemistry 24:8899-9002. https://doi.org/10.1039/D2GC02588D Meyer, D. E., Li, M., and Ingwersen, W. W. 2020. Analyzing economy-scale solid waste gen- eration using the United States environmentally-extended input-output model. Resources, Conservation and Recycling 157:104795. Milbrandt, A., Coney, K. Badgett, A., and Beckham, G. T. 2022. Quantification and evalu- ation of plastic waste in the United States. Resources, Conservation and Recycling 183:106363. National Academies of Sciences, Engineering, and Medicine (NASEM). 2022. Reckoning with the U.S. Role in Global Ocean Plastic Waste. Washington, DC: The National Academies Press. https://doi.org/10.17226/26132 North Carolina Department of Environmental Quality (NCDEQ). 2022. Pricing Trends. https://deq.nc.gov/about/divisions/environmental-assistance-and-customer-service/ recycling/programs-offered/recycling-business-assistance-center/recycling-markets/ pricing-trends Organisation for Economic Co-operation and Development (OECD). 2022. Global Plastics Outlook: Economic Drivers, Environmental Impacts and Policy Options. https://www. oecd-ilibrary.org/sites/de747aef-en/index.html?itemId=/content/publication/de747aef-en Rafter, D. 2016. MRF Tech is Rising, Bringing Financial Challenges. Stormwater Solu- tions. https://www.stormh2o.com/bmps/article/13027746/mrf-tech-is-rising-bringing- financial-challenges The Recycling Partnership. 2020. State of Curbside Recycling Report. https://recyclingpartner- ship.org/wp-content/uploads/dlm_uploads/2020/02/2020-State-of-Curbside-Recycling. pdf –––. 2021. Paying It Forward: How Investment in Recycling Will Pay Dividends. https:// recyclingpartnership.org/wp-content/uploads/dlm_uploads/2021/05/Paying-It- Forward-5.18.21-final.pdf ReportLinker. 2022. Global Plastic Recycling Industry. https://www.reportlinker.com/ p05896556/Global-Plastic-Recycling-Industry.html Republic Services. 2022. Republic Services Advances Circularity with Nation’s First In- tegrated Plastics Recycling Facility. https://investor.republicservices.com/news-releases/ news-release-details/republic-services-advances-circularity-nations-first-integrated Rogoff, M. J., and Clark, B. J. 2016. Mixed Waste Materials Recovery Facilities. MSW Management. https://www.mswmanagement.com/home/article/13023103/ mixed-waste-materials-recovery-facilities

MANAGEMENT AND SOURCING OF PLASTICS WASTE 63 RRS recycle.com. 2022. Economic Impact of Beverage Container Deposits on Municipal Recycling Processing Costs. Prepared for the National Waste & Recycling Association. https://wasterecycling.org/wp-content/uploads/2022/02/Impact-of-beverage-container- deposits-on-recycling-processing-costs-Final.pdf Schyns, Z. O. G., and Shaver, M. P. 2021. Mechanical recycling of packaging plastics: A re- view. Macromolecular Rapid Communications 42(3):e2000415. https://doi.org/10.1002/ marc.202000415 Sorensen, R. M., Kanwar, R. S., and Jovanovi, B. 2022. Past, present, and possible future policies on plastic use in the United States, particularly microplastics and nanoplastics: A review. Integrated Environmental Assessment and Management 19(2):474-488. https:// doi.org/10.1002/ieam.4678 Staley, B. F., and Barlaz, M. A. 2009. Composition of municipal solid waste in the United States and implications for carbon sequestration and methane yield. Journal of Environ- mental Engineering 135(10). Statista. 2022. Plastic Industry in China—Statistics and Facts. https://www.statista.com/ topics/8365/plastic-industry-in-china/#topicOverview –––. 2023. Plastics Sales and Captive Use in the United States in 2020 by Resin. https://www.statista. com/statistics/622845/total-plastics-sales-and-captive-use-in-the-united-states-by-resin Stina. 2021. 2020 U.S. Post-consumer Plastic Recycling Data Dashboard. https://circularity- inaction.com/2020PlasticRecyclingData Tonjes, D. J., Aphale, O., Clark, L., and Thyberg, K. L. 2018. Conversion from dual stream to single stream recycling results in nuanced effects on revenues and waste stream amounts and composition. Resources, Conservation and Recycling 138:151-159. https:// doi.org/10.1016/j.resconrec.2018.07.020 Tullo, A. 2022a. Dow unveils big recycling initiative. Chemical & Engineering News July 25:17. –––. 2022b. Dow and Mura pick Germany for first plant. Chemical & Engineering News September 19:10. –––. 2022c. All in on plastics pyrolysis. Chemical & Engineering News October 10:22-28. –––. 2022d. SK plans plastics pyrolysis in Korea. Chemical & Engineering News December 5:11. –––. 2022e. Dow and WM will collaborate on film. Chemical & Engineering News November 21:14. Tyler Packaging. 2021. Why Is It So difficult to Recycle Plastics? https://www.tylerpackaging. co.uk/problems-with-recycling-plastic United Nations Environment Programme (UNEP). 2018. The New Plastics Economy Global Commitment. https://www.unep.org/new-plastics-economy-global-commitment U.S. Environmental Protection Agency (USEPA). 2020. Advancing Sustainable Materials Management: 2018 Tables and Figures. https://www.epa.gov/sites/default/files/2021-01/ documents/2018_tables_and_figures_dec_2020_fnl_508.pdf –––. 2022. National Overview: Facts and Figures on Materials, Wastes and Recy- cling. https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/ national-overview-facts-and-figures-materials#Recycling/Composting U.S. Food and Drug Administration (FDA). 2022. Submissions on Post-Consumer Recycled (PCR) Plastics for Food-Contact Articles. https://www.cfsanappsexternal.fda.gov/scripts/ fdcc/index.cfm?set=RecycledPlastics U.S. Government Accountability Office (GAO). 2021. Science & Tech Spotlight: Advanced Plastics Recycling. GAO-21-105317. https://www.gao.gov/assets/gao-21-105317.pdf U.S. Plastic Pact. 2020. 2020 Baseline Report. https://usplasticspact.org/wp-content/uploads/ dlm_uploads/2022/03/U.S.-Plastics-Pact-Baseline-Report.pdf

64 RECYCLED PLASTICS IN INFRASTRUCTURE Vesilind, W. W., and Reinhart, D. 2002. Solid Waste Engineering. Pacific Grove, CA: Brooks/ Cole. Zbib, H., and Wøhlk, S. 2019. A comparison of the transport requirements of different curb- side waste collection systems in Denmark. Waste Management 87:21-32. https://doi. org/10.1016/j.wasman.2019.01.037

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Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities Get This Book
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In the U.S., most plastics waste is disposed in landfills, but a significant amount also ends up as litter on land, rivers, and oceans. Today, less than 10 percent of plastics waste is recycled in the U.S. annually. The use of recycled plastics in infrastructure applications has potential to help expand the market and demand for plastics recycling.

These are among the findings in TRB Special Report 347: Recycled Plastics in Infrastructure: Current Practices, Understanding, and Opportunities from the Transportation Research Board of the National Academy of Sciences, Engineering, and Medicine.

The report emphasizes that pursuing the recycling of plastics in infrastructure depends on goals, policy, and economics. To that end, life cycle economic and environmental assessments should be conducted to inform policies on plastics waste reuse.

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