Extended Producer Responsibility for Waste Electronics: An Example of Printer Recycling in the United Kingdom

In February 2003, European Union (EU) policy makers implemented a Directive that will make producers responsible for waste electrical and electronic equipment at end-of-life (known as the "WEEE" Directive). Under this new legislation, producers are required to organize and finance the take-back, treatment, and recycling of WEEE and achieve mass-based recycling and recovery targets. This legislation is part of a growing trend of extended producer responsibility for waste, which has the potential to shift the world's economies toward more circular patterns of resource use and recycling. This study uses life-cycle assessment and costing to investigate the possible environmental effects of the WEEE Directive, based on an example of printer recycling in the United Kingdom.
For a total of four waste management scenarios and nine environmental impact categories investigated in this study, results varied, with no scenario emerging as best or worst overall compared to landfilling. The level of environmental impact depended on the type of material and waste management processes involved. Additionally, under the broad mass-based targets of the WEEE Directive, the pattern of relationships between recycling rates, environmental impacts, and treatment and recycling costs may lead to unplanned and unwanted results. Contrary to original EU assumptions, the use of mass-based targets may not ensure that producers adapt the design of their products as intended under producer responsibility.
It is concluded that the EU should revise the scope of consideration of the WEEE Directive to ensure its life-cycle impacts are addressed. In particular, specific environmental objectives and operating standards for treatment and recycling processes should be investigated as an alternative to mass-based recycling and recovery targets.     

Thermodynamic rarity of electrical and electronic waste: Assessment and policy implications for critical materials

The strategic relevance of extracting raw materials from waste from electrical and electronic equipment (WEEE) in the EU is increasing due to value chain risks caused by geopolitical instability, accessibility of specific minerals, and decreasing reserves due to growing extraction rates. This article examines the quantities of so-called critical raw materials (CRMs) originating within WEEE streams from a depletion perspective. Presently, current recycling targets are based solely on mass collection and recycling rates. We examine the potential limitations of this approach using an exergy-based indicator named thermodynamic rarity. This indicator represents the exergy costs needed for producing materials from the bare rock to market. The case of Italy is used to explore the application of the indicator at the macro (national) and micro (company) level for the product categories “small electronics” and “screens and monitors.” Our estimations show significant differences between the mass and rarity of materials within Italian WEEE streams. While iron accounts for more than 70% of the weight of the product categories analyzed, it accounts for less than 15% of the rarity. Similarly, several CRMs with a small mass have a higher rarity value, for example, tungsten with less than 0.1% of the mass and over 6% of the rarity. The policy context is reflected upon, where it is argued that thermodynamic rarity can provide novel insights to support end-of-life WEEE decision-making processes, for example, target development and recycling standards setting to help prioritize material monitoring and recovery options.     

A study on the environmental aspects of WEEE plastic recycling in a Brazilian company

Purpose

The high consumption of electrical and electronic equipment motivated by the rapid technological advances seen over the years has lead to an increase in the generation of waste electrical and electronic equipment (WEEE). Such residues contain various dangerous substances and therefore deserve special attention. To that end, the Brazilian Policy on Solid Waste has provided guidelines on integrated and solid waste management, such as consumer electronics, aiming at their appropriate disposal and treatment through reverse logistics. In this context, the present work focuses on studying the recycling of some WEEE plastics.

Methods

This study was conducted using the methodological framework presented in the International Standard ISO 14040:2006 and aimed to determine the life cycle inventory (LCI) of a WEEE plastic recycling process in a company in Brazil. Having collected the data, it was possible to identify and quantify the environmental aspects caused by the recycling process of major plastics (acrylonitrile-butadiene-styrene (ABS) and high impact polystyrene (HIPS). The study was conducted in the only company in Brazil that operates WEEE plastic recycling in large scale.

Results and discussion

Some of the environmental aspects caused during the recycling process of the plastics under study were identified and quantified. As a result, besides presenting the inventory, it was also possible to determine a reduction in the consumption of energy and in CO₂ emissions. When compared to the production of virgin ABS and HIPS, the recycling processes for such plastics showed a reduction in energy consumption by approximately 90% for both plastics and a reduction in CO₂ emissions by approximately 84% for HIPS and 87% for ABS. The plastics recycled by the company retain over 90% of their virgin mechanical properties.

Conclusions

The study shows that recycling is highly relevant and that components present in WEEE received appropriate destination and treatment. Recycling avoids environmental impacts as it prevents WEEE from being disposed of in landfills and as the pellets of recycled plastics can re-enter the supply chain as raw materials. Considering the legislation in Brazil, the stage of collection/transport/treatment of WEEE conducted by the company under study presents strong indications of contributions to the environment, society, and economy of the country.

     

Implementing Individual Producer Responsibility for Waste Electrical and Electronic Equipment through Improved Financing

Under the European Union (EU) Waste Electrical and Electronics Equipment (WEEE) Directive, producers are responsible for financing the recycling of their products at end of life. A key intention of such extended producer responsibility (EPR) legislation is to provide economic incentives for producers to develop products that are easier to treat and recycle at end of life. Recent research has shown, however, that the implementation of EPR for WEEE has so far failed in this respect. Current WEEE systems calculate their prices according to simple mass‐based allocation of costs to producers, based on broad collection categories containing a mixture of different product types and brands. This article outlines two alternative approaches, which instead calculate charges for products sold by producers by classifying them according to their eventual end‐of‐life treatment requirements and cost. Worked examples indicate that these methods provide both effective and efficient frameworks for financing WEEE, potentially delivering financial incentives to producers substantial enough to affect their potential profitability and, as a likely consequence, the decisions relating to the design of their products. In particular they fulfill three important criteria required by the WEEE Directive: they can financially reward improved design, allocate costs of historic waste proportionately (on the basis of tonnes of new products sold), and provide sufficient financial guarantees against future waste costs and liabilities. They are also relatively practical for implementation because they are based solely on cost allocation and financing. Further research and investigation would be worthwhile to test and verify this approach using real‐world data and under various scenarios.     

Iterative screening LCA in an eco-design tool

A screening and simplified LCA method, is essential necessary to include environmental aspects in the stage of Research and Development (R&D) of products and processes. An interactive, iterative and integrative eco-design tool using the top-down approach in the identification of advanced materials is being developed in a joint project performed by six research institutes. The principles and methods as well as some examples for the validation of the screening LCA as well as its application in eco-design in case studies are presented in this article.     

A Statistical Analysis of Prices of Electrical and Electronic Equipment after the Introduction of the WEEE Directive

In January 2003, the European Union (EU) issued a directive on e‐waste (waste from electrical and electronic equipment; WEEE) to deal with increasing quantities and the included hazardous components. The WEEE Directive is based on the principle of extended producer responsibility, which shifts the responsibility for end of life of products away from municipalities toward producers. This led some researchers to state that, in theory, the costs of waste treatment are passed on to consumers in terms of higher prices. This work addresses two fundamental questions: (1) Did the introduction of the WEEE Directive increase consumer prices of electrical and electronic equipment (EEE)? and (2) how much is this price increase? We carry out, for the first time in the literature, a quantitative research on price variation of the vast majority of EEE sold in the EU after the introduction of producers’ financial responsibility. The panel data include 972 price level indices, namely, six categories of EEE for 27 member states for six years. The main result is that the average variation of the prices for each category of EEE investigated actually increased and the variation was between 0.71% and 3.88%, depending on the specific category of EEE. The average increase of 2.19% is in line with the previous studies that estimated the impact of the WEEE Directive up to a 3% increase of the product price. The t‐test performed on the data shows a good statistical significance, which strengthens the relevance of the results. Finally, future directions for research are included.     

Substance Flow Analysis of Wastes Containing Polybrominated Diphenyl Ethers

The present article examines flows and stocks of Stockholm Convention regulated pollutants, commercial penta‐ and octabrominated diphenyl ether (cPentaBDE, cOctaBDE), on a city level. The goals are to (1) identify sources, pathways, and sinks of these compounds in the city of Vienna, (2) determine the fractions that reach final sinks, and (3) develop recommendations for waste management to ensure their minimum recycling and maximum transfer to appropriate final sinks. By means of substance flow analysis (SFA) and scenario analysis, it was found that the key flows of cPentaBDE stem from construction materials. Therefore, end‐of‐life (EOL) plastic materials used for construction must be separated and properly treated, for example, in a state‐of‐the‐art municipal solid waste (MSW) incinerator. In the case of cOctaBDE, the main flows are waste electrical and electronic equipment (WEEE) and, possibly, vehicles. Most EOL vehicles are exported from Vienna and pose a continental, rather than a local, problem. According to the modeling, approximately 73% of cOctaBDE reached the final sink MSW incinerator, and 17% returned back to consumption by recycling. Secondary plastics, made from WEEE, may thus contain significant amounts of cOctaBDE; however, uncertainties are high. According to uncertainty analysis, the major cause is the lack of reliable values regarding cOctaBDE concentrations in European WEEE categories 3 and 4, including cathode ray tube monitors for computers and televisions. We recommend establishing a new, goal‐oriented data set by additional analyses of waste constituents and plastic recycling samples, as well as establishing reliable mass balances of polybrominated diphenyl ethers’ flows and stocks by means of SFA.     

Business‐to‐Business Information Technology User Practices at End of Life in the United Kingdom,Germany, and France

Business‐to‐business (B2B) electronics account for a significant volume of the electrical and electronic equipment (EEE) put on the market. Very little B2B waste electrical and electronic equipment (WEEE) is reported as collected in the European Union (EU) in compliance with the WEEE Directive, which uses the policy principle of extended producer responsibility (EPR) to ensure that WEEE is managed correctly. This presents a barrier to parties looking for access to the waste. Company practice dictates the channels into which B2B WEEE flows following primary use. This article presents a study that engaged with company actors directly to get a better understanding of business information technology (IT) EEE asset management. Data were collected to determine the barriers current practice could present to the collection of B2B IT EEE at end of life and the implications of these for the development of policies and strategies for EPR. A questionnaire was developed and data were gathered from organizations in three EU countries—the United Kingdom, Germany, and France—stratified by size. Some notable findings were that there are several routes by which end‐of‐life B2B WEEE can flow. The recycling and refurbishment of B2B IT units at end of use was shown to be commonplace, but it is likely that these units enter streams where they are not reported. The actors disposing of their units did not have information on the management or disposition of these streams. It is concluded that to achieve the goals of EPR for B2B IT WEEE, the networks and the operational practices of these streams need to be better understood when developing strategies and policies.     

New insights into polyurethane biodegradation and realistic prospects for the development of a sustainable waste recycling process

Polyurethanes are polymeric plastics that were first used as substitutes for traditional polymers suspected to release volatile organic hazardous substances. The limitless conformations and formulations of polyurethanes enabled their use in a wide variety of applications. Because approximately 10 Mt of polyurethanes is produced each year, environmental concern over their considerable contribution to landfill waste accumulation appeared in the 1990s. To date, no recycling processes allow for the efficient reuse of polyurethane waste due to their high resistance to (a)biotic disturbances. To find alternatives to systematic accumulation or incineration of polyurethanes, a bibliographic analysis was performed on major scientific advances in the polyurethane (bio)degradation field to identify opportunities for the development of new technologies to recondition this material. Until polymers exhibiting oxo- or hydro-biodegradative traits are generated, conventional polyurethanes that are known to be only slightly biodegradable are of great concern. The research focused on polyurethane biodegradation highlights recent attempts to reprocess conventional industrial polyurethanes via microbial or enzymatic degradation. This review describes several wonderful opportunities for the establishment of new processes for polyurethane recycling. Meeting these new challenges could lead to the development of sustainable management processes involving polymer recycling or reuse as environmentally safe options for industries. The ability to upgrade polyurethane wastes to chemical compounds with a higher added value would be especially attractive.     

生态设计家具的碳足迹核算与减排效果分析——以木质家具为例

我国的木质家具不仅产量大,而且碳排放强度也相对较高,利用生态设计理念可以降低木质家具的碳足迹。为了定量化生态设计所带来的减排效果,按照减少资源消耗和环境污染、节省住宅空间等木质家具生态设计原则,通过在一款多功能家具的框架内安装不同面板,形成了4种不同材质和结构的设计方案,利用生命周期分析方法核算了4种方案的碳足迹,并进一步量化了改进方案的减排效果。结果表明:4种家具设计的碳足迹从小到大为三聚氰胺板家具、木皮板家具、拼板家具、嵌条板家具,其中,实木类家具原材料碳排放较低,人造板类家具加工过程电力碳排放较低(主要来源于喷涂工段,占电力排放的83%—92%);通过各种减排方案的减排效果分析,发现采用"可拆卸无胶连接方式"改进方案减排效果显为明显;同时发现,合理的"低碳设计"(采用以实木板为基板,以三聚氰胺纸为贴面制作面板),可以避免中纤板喷涂过程的碳排放,从而减少产品整体碳足迹。     

Economic and environmental assessment of automotive plastic waste end-of-life options: Energy recovery versus chemical recycling

Most automotive plastic waste (APW) is landfilled or used in energy recovery as it is unsuitable for high-quality product mechanical recycling. Chemical recycling via pyrolysis offers a pathway toward closing the material loop by handling this heterogeneous waste and providing feedstock for producing virgin plastics. This study compares chemical recycling and energy recovery scenarios for APW regarding climate change impact and cumulative energy demand (CED), assessing potential environmental advantages. In addition, an economic assessment is conducted. In contrast to other studies, the assessments are based on pyrolysis experiments conducted with an actual waste fraction. Mass balances and product composition are reported. The experimental data is combined with literature data for up- and downstream processes for the assessment. Chemical recycling shows a lower net climate change impact (0.57 to 0.64 kg CO₂e/kg waste input) and CED (3.38 to 4.41 MJ/kg waste input) than energy recovery (climate change impact: 1.17 to 1.25 kg CO₂e/kg waste input; CED: 6.94 to 7.97 MJ/kg waste input), while energy recovery performs better economically (net processing cost of −0.05 to −0.02€/kg waste input) compared to chemical recycling (0.05 to 0.08€/kg waste input). However, chemical recycling keeps carbon in the material cycle contributing to a circular economy and reducing the dependence on fossil feedstocks. Therefore, an increasing circularity of APW through chemical recycling shows a conflict between economic and environmental objectives.     

Accounting for carbon flows into and from (bio)plastic in a national climate inventory

Despite the time-dependent behavior of carbon stored in plastic materials, literature assessing carbon flows into and from plastic typically applies a static approach. To better understand the climate impacts of such storage, this study explores how carbon stored in plastics can contribute over time to the national climate inventory with various emphasis on recycling. This is accomplished by implementing material stock change estimations for carbon in plastic materials that follow first-order decay and include impacts from recycling rates in the Integrated MARKAL-EFOM System model generator for Sweden (TIMES-Sweden). Thereafter, three approaches to how carbon released from the plastic material stock is accounted for in the national climate inventory were applied to determine how each approach affects resulting emission and net-zero pathways in different recycling rate scenarios. An accounting approach that follows the first-order decay pattern of material stocks was found to be important for capturing the impacts of recycling and for neither over- nor underestimating the emission impact from carbon stored in plastics. Accounting for carbon stored in plastics may provide important incentives for producing renewable plastics and reducing dependence on carbon removal technologies. Because of its synergies with recycling, the carbon storage potential of plastic products is well worth recognizing and promoting in a policy setting that aims for circularity. For Sweden, this reduces the need for bioenergy carbon capture and storage and makes more biomass-based carbon and electricity available for use elsewhere in the energy system.     

Strategic, Financial, and Design Implications of Extended Producer Responsibility in Europe: A Producer Case Study

Extended producer responsibility (EPR) legislation, making producers responsible for financing and organizing take-back and recycling of waste batteries, packaging, end-of-life vehicles (ELVs), and waste electrical and electronic equipment (WEEE), has been or is currently in the process of being implemented in 29 different countries in Europe following introduction of European Union directives. This article reviews the potential impacts of EPR for waste batteries, packaging, and WEEE on producers distributing products in Europe through a case study of Sony Computer Entertainment Europe (SCEE)—responsible for marketing and distribution of PlayStation products.
There are presently more than 250 producer responsibility organizations (PROs) established to meet EPR obligations in Europe, which contrasts to the single national recycling schemes founded in the late 1990s. SCEE estimates it avoided anetcostof €408,000 in 2005 by introducing competitive review of PRO services (against a total net take-back cost of €401,000).To meet increasingly extensive compliance obligations, SCEE has initiated new activities, with considerable implications for the company's legal, sales data administration, procurement, accounting, and product and packaging approval practices.
Considering the ultimate aim of EPR to establish economic incentives for improved product design, several significant political and practical obstacles are described from SCEE's case and industry situation. Although the principle of EPR is indeed interesting, its practical application in Europe may require refinement. Producers, given adequate support by policy makers, still have opportunities to develop new processes under the WEEE Directive to facilitate design for the environment.     

The use of meta-analysis in food contact materials risk assessment

Abstract

As materials intended to be brought into contact with food, food contact materials (FCMs) – including plastics, paper or inks – can transfer their constituents to food under normal or foreseeable use, including direct or indirect food contact. The safety of FCMs in the EU is evaluated by the European Food Safety Authority (EFSA) using risk assessment rules. Results of independent, health-based chemical risk assessments are crucial for the decision-making process to authorize the use of substances in FCMs. However, the risk assessment approach used in the EU has several shortcomings that need to be improved in order to ensure consumer health protection from exposure arising from FCMs. This article presents the use of meta-analysis as a useful tool in chronic risk assessment for substances migrating from FCMs. Meta-analysis can be used for the review and summary of research of FCMs safety in order to provide a more accurate assessment of the impact of exposure with increased statistical power, thus providing more reliable data for risk assessment. The article explains a common methodology of conducting a meta-analysis based on meta-analysis of the dose-effect relationship of cadmium for benchmark dose evaluations performed by EFSA.     

Extended Producer Responsibility in Thailand

Waste electrical and electronic equipment (WEEE) sheds light on the dimmer side of production and consumption patterns in modern societies. The rapid increase in its quantity and complexity contribute to the challenges it poses to solid waste management systems. Several members of the Organisation for Economic Co‐operation and Development (OECD) have relied on the principle of extended producer responsibility (EPR) to tackle the issue, with varying degrees of success. Several non‐OECD countries, including Thailand, are now developing WEEE programs and are looking for lessons from these first movers. This case study aims to provide an understanding both of this context and of the EPR program for WEEE proposed for Thailand. It finds that EPR mechanisms in general, and the proposed buy‐back system financed by product fees in Thailand in particular, have a strong potential to consolidate WEEE collection for the formal recycling sector by offering end users monetary incentives. On the negative side, this is an expensive combination of policy instruments, and the institutional design of the governmental fund is rigid. The policy proposal also contains no mechanism for product redesign—one of the objectives in the national WEEE strategy. This article suggests that the effectiveness of the policy might benefit from more flexibility at the compliance scheme level, in order to lessen the monopoly of the governmental fund, as well as the introduction of differentiated fees to promote environmentally friendly products.     

Dimensionality Reduction and Visualization of the Environmental Impacts of Domestic Appliances

There is an increasing worldwide concern about the problem of dealing with the waste electrical and electronic equipment (WEEE), given the high volume of appliances that are disposed of every day. In this article, an environmental evaluation of WEEE is performed that combines life cycle assessment (LCA) methodology and multivariate statistical techniques. Because LCA handles a large number of data in its different phases, when one is trying to uncover the structure of large multidimensional data sets, multivariate statistical techniques can provide useful information. In particular, principal‐component analysis and multidimensional scaling are two important dimension‐reducing tools that have been shown to be of help in understanding this type of complex multivariate data set. In this article, we use a variable selection method that reduces the number of categories for which the environmental impacts have to be computed; this step is especially useful when the number of impact categories or the number of products or processes to benchmark increases. We provide a detailed illustration showing how we have used the proposed approach to analyze and interpret the environmental impacts of different domestic appliances.     

塑料添加剂向生态环境中的释放与迁移研究进展

塑料废弃物,尤其是粒径小于5 mm的微塑料造成的环境污染问题已引起全球的普遍关注。塑料制品在生产过程中常使用多种添加剂,以提高聚合物的性能并延长其使用寿命。然而,在废弃塑料制品的回收及自然老化过程中,这些添加剂会不断释放出来,对生态环境的安全与人类的健康产生威胁。综述了近年来国内外塑料添加剂的使用情况及其向生态环境释放与迁移等方面的研究进展,具体包括常用塑料添加剂的种类、废弃物塑料回收和塑料老化过程中添加剂向生态环境中的释放与迁移及机制等。未来需要更加关注绿色塑料添加剂的研发、废弃塑料回收工艺的改进以及关于塑料添加剂的释放、在各类环境介质中的迁移转化以及在生态系统各个圈层间的相互作用方面的系统性的研究,并构建相应的迁移模型评估塑料添加剂产生的生态风险。     

Plastics recycling: challenges and opportunities

Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide.Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel.While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it may be possible to divert the majority of plastic waste from landfills to recycling over the next decades.     

聚乳酸塑料合成、生物降解及其废弃物处置的研究进展

随着国内外禁塑令和限塑令的升级,以聚乳酸(polylactic acid, PLA)为代表的生物基塑料成为传统石油基塑料市场的主要替代品,备受产业界的青睐。然而,公众对生物基塑料的认识仍存在诸多误解。事实上,生物基塑料的降解需要在特定条件下才能实现,泄入到自然环境中同样难以降解,会对人体、生物多样性和生态系统功能造成危害,这与传统石油基塑料相似。近年来,随着我国PLA产能和市场规模不断的提高,亟需进一步加强对PLA等生物基塑料降解性能的认识,挖掘PLA生物降解资源,关注和研究生物基塑料回收处理模式。基于上述背景,本文首先介绍了PLA塑料的性质及合成方式,以及PLA塑料的产业化与市场规模;其次,对目前聚乳酸塑料微生物与酶法降解的研究进展进行了综述,并对其生物降解机制进行了探讨;最后,提出了微生物原位处理和酶法闭环回收两种聚乳酸塑料废弃物生物处置方法,并对PLA生物基塑料的发展前景和趋势进行了展望。     

Design of recycling system for poly(methyl methacrylate) (PMMA). Part 1: recycling scenario analysis

Introduction

In this series of papers, we present a poly(methyl methacrylate) (PMMA) recycling system design based on environmental impacts, chemical hazards, and resource availability. We evaluated the recycling system by life cycle assessment, environment, health, and safety method, and material flow analysis.

Purpose

Previous recycling systems have not focused on highly functional plastics such as PMMA, partly because of lower available volumes of waste PMMA compared with other commodity plastics such as polyethylene or polypropylene. However, with the popularization of PMMA-containing products such as liquid crystal displays, the use of PMMA is increasing and this will result in an increase in waste PMMA in the future. The design and testing of recycling systems and technologies for treating waste PMMA is therefore a high research priority. In this study, we analyze recycling of PMMA monomers under a range of scenarios.

Methods

Based on the differences between PMMA grades and their life cycles, we developed a life cycle model and designed a range of scenarios for PMMA recycling. We obtained monomer recycling process inventory data based on the operational results of a pilot plant. Using this process inventory data, we quantified life cycle greenhouse gas (LC-GHG) emissions and fossil resource consumption, and we calculated the LIME single index.

Results and discussion

PMMA produces more than twice the amount of GHG emissions than other commodity resins. Through scenario and sensitivity analyses, we demonstrated that monomer recycling is more effective than mechanical recycling. Operational modifications in the monomer recycling process can potentially decrease LC-GHG emissions.

Conclusions

Highly functional plastics should be recycled while maintaining their key functions, such as the high transparency of PMMA. Monomer recycling has the potential to achieve a closed-loop recycling of PMMA.