A Review of Existing Plastic Waste Management Strategies, Assessment & Tools: Towards the Development of a Plastic Offsetting Strategies

Abstract

The escalating global production of plastics poses significant environmental challenges, such as greenhouse gas (GHG) emissions and widespread pollution. This review critically examines contemporary research on plastic sustainability strategies, focusing particularly on the circular economy (CE), end-of-life management, and emerging concepts such as offsetting. Despite various initiatives advocating the reduce–reuse–recycle (3Rs) approach, only 9–10% of plastic is effectively recycled, with substantial volumes incinerated or landfilled, exacerbating environmental degradation. Moreover, the review highlights geographic disparities, highlighting that regions with robust infrastructure achieve more effective waste management than developing areas. The adoption of bioplastics as sustainable alternatives remains limited due to their complex life cycle and production processes. This review synthesizes the CE, Life Cycle Assessment (LCA), and offsetting tools in the context of plastics towards the development of plastic offsetting strategies as a waste management solution. It identifies critical literature gaps, where existing plastic waste management systems are limited to affordability and geographical restrictions. The review highlights the various plastic circularity strategies and their limitations, while addressing carbon offsetting as an inspiration for a plastic offsetting mechanism that could significantly enhance global strategies to mitigate plastic pollution, particularly in developing regions, fostering more sustainable global waste management practices. Therefore, plastic offsetting, inspired by carbon offset mechanisms, emerges as a novel strategy that offers financial incentives by sponsoring plastic waste management projects to effectively managing plastic waste in less developed regions.

1. Introduction

Plastic production is projected to contribute about 15% to global GHG emissions by 2050 [1]. Therefore, environmental activists have urged the international community to recognize the harm that single-use plastics cause—not only to marine life and ecosystems through pollution, but also via significant GHG emissions across their life cycle. In this regard, the international community must develop sustainable solutions to honor the Paris Agreement’s goal of keeping global temperatures below 2 °C above pre-industrial levels [2]. International companies are actively pursuing various strategies to lower carbon emissions. Many have adopted CE practices, while others have invested in bolder approaches, such as carbon offsetting, to achieve global benefits.

In addition to GHG emissions, plastic waste is causing widespread pollution. Irresponsible disposal leaves microplastics accumulating in oceans, rivers, beaches, and other natural environments. According to a UN report, an estimated 75–199 million tonnes of plastic are already in the oceans, significantly impacting aquatic life. In 2016, an estimated 9–14 million tonnes of plastic entered the oceans; this annual input is expected to rise to 23–37 million tonnes by 2040 [3]. Plastic pollution also severely affects wildlife—especially marine life—by causing ingestion, entanglement, and suffocation in many aquatic species [4]. Humans are not immune to its effects; toxic gases released by the degradation of plastics can irritate or damage the eyes, skin, and respiratory system, and may affect organs such as the liver and gut [5].

One major pathway for plastics to reach the oceans is via rivers. Rivers are a primary conduit for plastics to the oceans; in fact, most waste collected in rivers consists of plastic items such as food containers (35.8%), bags (22.8%), and wrappers (10.2%) [6]. Asian river systems contribute the most to ocean plastic pollution [7]. Asia alone accounts for about 64.8% of global plastic leakage into oceans, far more than any other continent; see Figure 1.

Mismanaged plastic (plastic that is not landfilled, incinerated, or recycled) is least prevalent in Europe and North America—regions with the most developed waste management efforts. In contrast, Asia and Africa together account for more than 86% of the global mismanaged plastic waste. Globally, only about 9–10% of plastic waste is recycled (Figure 2). This low recycling rate shows that recycling alone cannot keep pace with the ever-increasing rate of plastic production. In other words, current waste management strategies (even in CE models) are not sufficient, putting pressure on stakeholders to find more realistic, upstream solutions to the plastic waste problem.

The common practice for sustainability practitioners is to consider the carbon footprint, GHG emissions, and other environmental impacts throughout the life cycle of a product—from raw material extraction through manufacturing, storage, transport, and end use to final disposal. Traditionally, such product life cycles were ‘cradle to grave’ (ending in disposal), resulting in significant waste accumulations. Recently, there has been a shift towards ‘cradle to cradle’ systems, which promote reducing, reusing, and recycling (the 3Rs) as part of the CE agenda [8]. On average, producing 1 kg of plastic resin results in an estimate of 2.9 kg ${\mathrm{CO}}_2$ equivalent (${\mathrm{CO}}_2\mathrm{eq}$) emissions, where ${\mathrm{CO}}_2\mathrm{eq}$ denotes carbon dioxide equivalent emitted to atmosphere. Furthermore, 1 kg of plastic is incinerated at end-of-life, an additional 2.7 kg ${\mathrm{CO}}_2\mathrm{eq}$ is emitted (In perspective, the production of 1 kg of plastic, plus incineration, emits roughly as much ${\mathrm{CO}}_2$ as driving a typical car traveling for 23–25 km) [9]. Considering that Europe’s plastic life cycle emissions are about 132.26 million tonnes of ${\mathrm{CO}}_2\mathrm{eq}$ per year, it is clear that new methods are needed to reduce emissions and make plastic production more sustainable. It has been reported that even with aggressive waste management recycling, which can prevent 1.1–3.0 tons of ${\mathrm{CO}}_2\mathrm{eq}$ compared to incinerating one ton of virgin plastic, it is not sufficient to reduce global emissions [9].

There is an urgent need to develop both strategic and technological solutions for better plastic waste management. Potential approaches include using LCA to evaluate the environmental impacts; adopting more sustainable end-of-life options (e.g., chemical recycling or energy recovery where appropriate); enhancing public awareness and participation in recycling; utilizing innovative techniques to reduce, reuse, recycle plastic waste (the 3Rs); and exploring eco-friendly alternative materials to conventional plastics [10].

The literature review examines prior studies encompassing various aspects of plastic sustainability. Although plastics differ by polymer type and impact profile, the proposed offsetting logic is intended to apply across plastic types; credit units may be refined to reflect polymer-specific leakage risk or impact-weighted scoring where appropriate. Several recent reviews have addressed individual elements of the problem, but none have combined them to examine the emerging concept of plastic offsetting that refers to financing verified interventions that measurably reduce mismanaged plastic waste relative to a baseline scenario (e.g., improved collection and safe end-destinations, recycling that displaces virgin production, and/or leakage-prevention in high risk geographies). Several reviews have been published on related topics. For example, Bishop et al. (2021) [11] and Rhein and Sträter (2021) [12] both provided reviews of LCA methodologies for plastics compared to bioplastics (with an emphasis on recycling over reduction and reuse strategies), and Hatti-Kaul et al. (2020) [13] reviewed advances in recyclable and bioplastics. Similarly, Wei et al. (2021) [14], reviewed global trends in carbon offsetting. Eventually, there is an opportunity to advance concept of plastic offsetting. As such the objectives of this review are as follows:

• To review reputable literature on the environmental impacts of plastics.
• To examine the CE concept within the plastic industry, demonstrating why a CE approach alone may not achieve sustainability goals within the pledged timeframes.
• To investigate various environmental measures, tools, and strategies—such as LCA, alternative materials (bioplastic), and offsetting mechanisms that could form the building blocks of a plastic offsetting framework.

These objectives address a notable research gap, related to the development of a comprehensive review combining CE, LCA, and other plastic waste management strategies in the context of developing a plastic offsetting mechanism. As such the novelty of this review is to review the building blocks that can contribute towards the development of a plastic offsetting mechanism as a novel waste management strategy to reduce global plastic waste. The methodology of the review includes the CE concept and the end-of-life with their associated challenges, reviewing the tools and metrics (e.g., LCA and EIA) used to assess plastic’s environmental impacts, their limitations, examining existing sustainability strategies such as the 3Rs, bioplastics, and carbon offsetting. Then, the research gaps are discussed to highlight the importance of implementing a plastic offsetting mechanism to address global plastic waste management.

2. Literature Review Methodology

The literature on plastics encompasses their history, utility, and environmental challenges, which necessitates a comprehensive exploration to develop a nuanced understanding of the field. This literature review meticulously examines a broad spectrum of scholarly works, ranging from the development and commercialization of plastics and their vital role in modern society to the burgeoning concerns about plastic pollution and strategies to mitigate it. By critically analyzing contributions from various researchers, this section aims to highlight the multifaceted impacts of plastics on the environment, economic dynamics, public health, and global efforts towards sustainability and waste management. This review aims to capture the current knowledge landscape, identify gaps in research and potential avenues for future investigation, and provide context for the study objectives.

To gather relevant literature, Google Scholar was used to search for publications (focusing on peer-reviewed journal articles published in English) using the keywords “carbon footprint”, “offsetting”, “life cycle”, “environmental assessment tools”, “bioplastics”, “microplastics”, and “environmental impacts of plastics”. Google Scholar was chosen for its comprehensive search on the subjects to ensure coverage of plastic offsetting. Following the PRISMA framework, the following terms were used [“Carbon Offsetting” OR “Carbon Credit” OR “Plastic offsetting” OR “plastics life cycle” OR “Plastics Circular Economy” OR “Plastics Waste Management”] and the search was limited to peer-reviewed reviews published in English between the years 2002 and 2022. The search was performed in August 2022. The search resulted in 1970 articles, which were filtered based on relevance.

Out of 1970 articles found by Google Scholar search, 1903 were found not related to the review objectives; as; mainly focused on general waste (municipal waste), are not plastic-focused articles, are redundant in their focus on recycling non-plastic materials, and address other topics. Out of the 1970 articles found, only 67 articles were found relevant, which were categorized into six main topic areas: (1) circular economy, (2) plastic life cycle, (3) plastic waste, (4) microplastics and their environmental impacts, (5) bioplastics (as alternatives), and (6) carbon offsetting, as shown in Figure 3.

The categorization was conducted to evaluate the focus areas of the literature, with about 91% of the reviewed literature covering the life cycle of plastics and waste management topics (including microplastic leakage and the CE). Around 6% is allocated to bioplastics as an alternative strategy. Only 3% of the sources discuss carbon offsetting mechanisms, and none address plastic offsetting specifically. Based on the literature review criteria and the analysis, the literature was found to have a gap where no comprehensive review was found to examine the various elements that can contribute to plastics offsetting mechanism, inspired by carbon offsets, which can support plastic industries in balancing their overall environmental impact and reduce plastic waste globally.

3. Circular Economy in Plastics

The origins of the CE concept are often traced back to 1966 when Kenneth E. Boulding discussed the idea in his essay ‘The Economics of Coming Spaceship Earth’, contrasting it with the traditional linear economy (take–make–dispose) [15]. The concept gained further development in the 1990s by British economists, David W. Pearce and R. Kerry Turner, who described an economic system in which waste from extraction, production, and consumption is turned into input for a new process [16]. The Ellen MacArthur Foundation defines CE as “The circular economy is a system where materials never become waste and nature is regenerated. In a CE, products and materials are kept in circulation through processes like maintenance, reuse, refurbishment, remanufacture, recycling, and composting” [17].

The United Nations Environment Assembly 2019 describes CE as a model that uses products and materials that can be reused, remanufactured, recycled, or recovered, maintaining the economy for future generations [3]. Within the plastic industry, a CE approach means designing systems to optimize the use of raw materials and minimize environmental impacts across production, distribution, and consumption. It also prioritizes feeding waste material back into the production cycle (via reuse or recycling) rather than disposing of it. This can include improving manufacturing processes to produce higher-quality (more durable or more recyclable) plastics and enhancing reuse, remanufacturing, and recycling efforts to maximize resource efficiency [18]. A key component of a circular plastic economy is rigorous waste management, essentially the 3Rs (reduce, reuse, recycle)—which reduces the need for raw materials.

Notably, the definition of CE is debated where the term can carry various interpretations [19]. However, they all essentially involve planning across the entire plastic value chain to eliminate waste and optimize resource use. Both industry and government have important roles—for instance, providing incentives to increase plastic collection and segregation, and encouraging companies to design plastic products with recyclability and optimization of materials use [15]. There are several reasons for moving from a linear to a CE in the plastics industry [20] plastic production leads to a correspondingly larger amount of waste—including micro- and nano-optimized material use—which poses a severe risk to ecosystems and human health. Furthermore, plastic production (and even specific recycling processes generate significant GHG emissions. For example, producing plastic resins requires energy (often from steam) and can release toxic chemicals; many older petrochemical (plastic) plants rank among the top five most polluting industries in terms of emissions [20].

It is important to consider CE in the context of sustainability to ensure Economic prosperity, environmental benefits, while considering social aspects such as the equitable access to resources for future generations. In this regard, consumer awareness is critical for achieving plastic recyclability and circularity. In many developing countries, public awareness of recycling and sustainability is low. For instance, households may not sort or segregate plastic waste from other trash, making it difficult for recycling companies to recover it. Improving waste management requires making it everyone’s responsibility. Therefore, environmental education programs are needed at all levels—for children, parents, and communities—to increase awareness of plastic types and the importance of segregating plastic waste [21]. Engaging the younger generation is essential, as habits formed early can foster a more sustainable mindset in society.

One of the key challenges to implementing CE is end-of-life management, as most plastics will eventually be landfilled or incinerated. According to Kumar et al. (2021) [10] as of 2019, about 370 million tons of plastic were produced globally, but only 9% was recycled and 12% incinerated; the rest is accumulated in landfills or in nature [18]. Landfilling and incineration both increase carbon emissions; however, if effective 3R practices are implemented, the amount of waste requiring disposal is minimized, thereby reducing overall life cycle GHG emissions. Studies have shown that recycling often only delays the inevitable fate of plastics (final disposal), so the industry must focus more on reducing production itself, rather than only dealing with the consequences by recycling waste [22]. The primary end-of-life options for plastics can be summarized in

Table 1. GHG emissions for various end-of-life options [9].

End-of-Life Options	GHG Emissions $({\mathbf{kg} \mathbf{CO}}_2\mathbf{eq})$ Per kg of Polymer
Recycling	0.32
Incineration	2.71
Energy Recovery	−0.98
Landfilling	0.03

[23] and are described below:

• Landfill: The process of burial of waste in land disposal sites. For most plastics, landfilling results in ~0.03 ${\mathrm{kg} \mathrm{CO}}_2\mathrm{eq}$ of GHG per 1 kg of polymer; however, degradation of certain plastics (PE, PET, and PVC) in landfills can also generate organic pollutants.
• Incineration (flaring without energy recovery): The process of burning waste, mainly for mixed plastics that cannot be segregated for use/recycle. It generates 2.71 ${\mathrm{kg} \mathrm{CO}}_2\mathrm{eq}$ of GHG per 1 kg of plastic, along with emissions of steam and cinders (residual ash).
• Energy Recovery: Incineration with energy recovery uses the heating value of (~40 MJ/Kg). Approximately 1 kg of plastic waste can yield up to 1 L of fuel oil, or equivalently converted to heat, or electricity, preventing about 0.98 ${\mathrm{kg} \mathrm{CO}}_2\mathrm{eq}$ emissions per kg of polymer (i.e., a net negative emission when replacing fossil fuel). This is considered one of the most viable end-of-life options for plastics.
• Recycling: processing waste plastic into new products. Different recycling methods result in 0.32 ${\mathrm{kg} \mathrm{CO}}_2\mathrm{eq}$ emitted per 1 kg of reprocessed plastic (excluding the avoided production of virgin materials) which is lower than emissions associated with incineration.

Research indicates that phasing out single-use plastics is crucial for waste reduction, since single-use plastics are most harmful to the environment [24]. Manufacturers, meanwhile, are reluctant to change business-as-usual practice. Therefore, government regulations (e.g., bans or targets on single-use items) are required to drive progress. However, substituting single-use plastic with other materials can introduce new challenges and costs, and attempts to reuse single-use items can sometimes increase waste and pollution, ultimately hindering CE goals.

3.1. Limitations to Circularity: Design and Hazardous Additives

The design and material composition of plastics limit circularity. Many plastics contain chemical additives that hinder recycling or pose health/environmental risks. Assessing and controlling the chemicals used in plastic production is critical for human and ecological health, as certain additives can impede recyclability and burden the CE [25]. Hazardous additives (e.g., certain plasticizers or flame retardants) have been identified as barriers to recycling; substituting these with safer alternatives would improve recyclability. Therefore, imposing regulations to phase out or restrict such chemicals is crucial for advancing a circular plastic economy. Wagner and Schlummer (2020) [26] highlighted issues with legacy additives (hazardous chemicals like certain persistent organic pollutants, POPs, and other substances of very great concern, SVHCs) present in older plastic products, and how they complicate disposal and recycling processes. They suggest that regulations must also limit the reuse or recycling of materials containing such legacy additives to minimize environmental and health risks. A recent report by the European Chemical Agency (2021) [27] noted that ‘chemical recycling’ is an umbrella term covering a broad spectrum of technologies, each contributing differently to circularity depending on their specific goal. The report raised concerns about the traceability of chemicals through recycling processes—suggesting that digital tracking technologies could help, though significant effort and coordination would be required.

Design improvements can also involve material choices, for example, using renewable or bio-based feedstock instead of fossil feedstocks drawing their own considerations [28]. Crippa et al. (2019) [28] suggested that better product design and keeping plastics circulating in the economy longer will increase their value and reduce environmental and health risks. As they state, “Moving towards a CE, we can harness the benefits of plastics while achieving better economic, environmental, and social outcomes”. On the other hand, certain design choices currently hinder circularity. For instance, products made from multiple plastic types are more difficult to recycle, especially if those plastics cannot be easily separated from other waste streams. Studies also show that much of today’s recycling is downcycling (producing lower-quality materials than the virgin plastic). Mechanical recycling is usually the primary method, although it faces persistent challenges in collecting and segregating waste which isone of the top hurdles to circularity in the plastics industry [29].

Bucknall (2020) [30] noted that a truly circular plastics economy cannot be achieved without innovative technological developments and significant economic investment. That study highlighted numerous interrelated technical challenges and emphasized that overcoming them will be necessary to attain circularity in the plastics industry. Technological advancements, such as biotechnology, are contributing to circularity by enabling new polymers from renewable feedstock and improving biopolymers’ properties (e.g., making them more degradable or easier to recycle) [13]. Such innovations can enhance plastic recyclability and reduce reliance on virgin fossil-derived materials. Public participation is also important where increased collection by individuals/municipalities makes it easier to divert plastic waste from landfills or incinerators into recycling streams. It is estimated that plastic production consumes roughly 4% of the global oil and gas as raw materials feedstock, and an additional 3–4% is expended to provide energy for the manufacturing process [31]. Therefore, the industry should seek alternatives that extend plastics’ life or recover value at end-of-life—for example, utilizing waste plastics for energy (incineration with energy recovery) to minimize landfilling. Recycling has the smallest environmental impact of all options—lower than incineration (with or without energy recovery) or landfilling [32]. Aryan et al. (2019) [32] stipulated that these benefits are largely because recycling displaces virgin material production and because the recycling process itself emits less GHG than producing new plastic.

3.2. Limitation to Circularity: Stakeholder Awareness and Commitment

Apart from technical factors, stakeholder mindset and engagement are vital in transitioning from a linear to a CE. Case studies illustrate this need for engagement. For example, Dow Chemical (a major plastic producer) demonstrated that strong support and involvement from all levels of stakeholders—from executives to engineers—was critical in advancing circular initiatives in the company. Similarly, Barford and Ahmad (2021) [33] emphasizes that full awareness among decision-makers of all available circular approaches accelerates progress toward circularity. Paletta et al. (2019) [34] analyzed plastic manufacturing companies knowledge about CE practices where they found that more companies are willing to incorporate recycled (non-virgin) plastic into their products to meet the EU’s 2025 recycling targets (in line with the European Strategy for Plastics in a CE). This suggests that awareness and understanding can lead businesses to change their strategies toward circular goals proactively. They also found that achieving circularity in practice requires not only economic and technological innovations but also overcoming social barriers throughout the product life cycle. Khan et al. (2020) [35] surveyed about attitudes, showing that 83% of organizations feel responsible for recycling their plastic waste, yet only 24% are satisfied with their current recycling efforts, underscoring that more external incentives or regulations may be needed. They also listed many practical barriers that face circularity:

• Lack of sufficient recycling facilities or easy access to them.
• Difficulties in transporting waste to recycling plants.
• Limited space or on-site waste storage.
• Inadequate funding for recycling initiatives.
• Shortage of skilled personnel or technology for effective plastic sorting.
• Lack of environmental experts to guide management.
• Insufficient market demand or buyers for recycled materials.

Possible measures to overcome these barriers have been identified by Khan et al. (2020) [35], for example providing training to organizations on waste management and recycling best practices; creating policies or incentives to encourage selling or reusing plastic waste (so that it becomes a resource rather than waste); increasing funding and investments in recycling infrastructure and technologies; implementing more strict regulations to minimizing waste generation at the source; and improving the economic feasibility of recycling for business (e.g., through subsidies or markets for recycled products).

3.3. Limitations to Circularity: Standardization & Regulation

It is difficult to definitively say which type of polymer has the lowest environmental impact—the answer often depends on how the analysis is done. For example, Walker and Rothman (2020) [36] compared fossil-based vs. bio-based polymers and found the results vary depending on the LCA methodology, end-of-life scenarios and even the source of the bio-based feedstock. This illustrates how methodological differences can lead to different conclusions about which polymer is ‘greener’. Moreover, differences in regional waste management systems and the lack of unified recycling standards pose a challenge for implementing circular strategies globally. Shamsuyeva and Endres (2021) [37] argued that collaboration with standardization committees is essential to develop consistent recycling standards and best practices. It is worth noting that plastic waste is a global issue—plastics often cross borders as waste exports/imports—and not all regions enforce circular practices. This uneven participation suggests that additional strategies may be needed on a global scale. In light of this, the plastic industry and governments are required to set regulations and realistic goals to achieve circularity and minimize plastic waste.

Notably, the term ‘circularity’ itself is sometimes used loosely. Firms may make broad self-commitments to CE principles (often for strategic or political appearance) without genuine intent to follow through. This ambiguity shows that firms may make self-commitments solely for political and strategic purposes, with no intention of pursuing a genuine interest in their execution [38,39,40]. Clear objectives and shared terminology are needed to properly evaluate such commitments, because purely voluntary self-regulation can preempt stricter policy intervention yet still result in inadequate environmental protection [38,39,40]. This is especially significant since political-strategic business self-regulation can avert political involvement while also resulting in poor environmental protection measures [41,42].

4. Metrics and Assessment Tools

While reduce–reuse–recycle and CE strategies are pursued, it is crucial to use quantitative tools to assess whether these approaches actually benefit the environment. This section reviews two key assessment tools: Life Cycle Assessment (LCA) and Environmental Impact Assessment (EIA). The LCA methodology evaluates the environmental impacts (e.g., carbon footprint, toxicity and others) of plastics across their entire life cycle (from raw material extraction to end-of-life). Whereas, EIA, examines the environmental effects of plastics (including plastic waste and particles) on ecosystems and human health, often in a specific context or project. Therefore, the difference is that LCA addressed the impacts while EIA addresses the effects. By applying these tools, one can identify which parts of the plastic life cycle carry the highest impacts, and thus where improvements or interventions (including potential offset measures) would be most needed to reduce overall environmental, social, and economic impacts.

4.1. Life Cycle Assessment (LCA)

Life Cycle Assessment (LCA) is a standardized methodology (ISO 14040) for evaluating the environmental impacts of a product or service throughout its entire life cycle (from raw material extraction to disposal) [43]. Unlike a carbon footprint analysis, which focuses only on GHGs, a full LCA examines multiple impact categories (e.g., climate change, water use, toxicity), providing a comprehensive view of a product’s environmental performance [44]. An important aspect of LCA is transparency within methodology and data since. The assumptions and data sources used can significantly affect the results. Truly transparent, unbiased LCA studies yield robust quantitative assessments of a product or system’s environmental performance, making them powerful tools for informing policy decisions. LCA is useful for evaluating strategies in both emerging and developed economies as they transition toward sustainability. It helps decision-makers understand trade-offs between different impacts—for example, an LCA can reveal how a change aimed at increasing recycled content might affect water usage, energy demand, or other factors. For instance, if a company aims for a product made of 100% recycled material, LCA can highlight the additional utilities or processing needed to achieve that (and whether contaminants accumulated in recycled material pose issues), ensuring that such a strategy is truly beneficial overall [44]. LCA can also be used to compare plastic with potential substitute materials (such as paper, cotton, and metal) for single-use items. This ensures that bans or shifts away from plastics do not unintentionally cause greater harm in other categories. A proper sustainability assessment must cover all relevant impact categories such as water use, climate change, land use, pollution (e.g., litter), resource depletion—and socio-economic factors (e.g., effects on livelihoods or sanitation access) [45].

The literature is rich with examples of LCAs conducted such as Alsabri and Al-Ghamdi (2020) [46] who performed an LCA on PVC, PE, and PP production. They found that PVC production uses the most energy and has the highest global warming impact among the three; however, recycling PVC significantly reduces its emissions, making it a preferable end-of-life option compared to landfilling or producing new PVC. Another LCA compared mechanical recycling versus energy recovery of plastic waste, showing that recycling generally emits less and yields greater environmental benefits. Rajendran et al. (2013) [47] examined the net impacts of recycling and estimated that recycled plastic can substitute for about 70–80% of virgin plastic in specific applications, demonstrating substantial potential for offsetting virgin production. Rhein and Sträter (2021) [12] reviewed the sustainability commitments of ten plastics manufacturers and found that ‘reduce’ and ‘reuse’ are often conflated with recycling in practice—companies tend to focus on recycling while neglecting actual reduction or reuse, thereby misrepresenting their CE efforts. Separately, Nicholson et al. (2021) [48] quantified the GHG emissions of the US plastics (polymer) industry at about 104 million tons ${\mathrm{CO}}_2 \mathrm{eq}$ per year and compared them to scenarios with increased bio-based content and circular practices. Peña et al. (2021) [49] advocates using LCA to evaluate the implementation of CE strategies, identifying potential environmental benefits and any unintended consequences or trade-offs.

It is also important to consider factors such as local sourcing versus long supply chains in LCA studies, as they can affect both environmental impacts (transport emissions) and socio-economic outcomes in supplier communities [49]. Such considerations also entail socio-economic implications for supplier regions. Notably, conventional LCA impact categories do not yet capture the specific impacts of plastic debris or litter in the environment [50], such as, issues related to microplastic pollution which are outside the scope of standard LCA and could be addressed in an Environmental Impact Assessment (EIA).

4.2. Environmental Impact Assessment (EIA)

An Environmental Impact Assessment (EIA) for plastics would assess the environmental impacts of plastic production and use across all forms and applications. Plastics production stages consume natural resources (i.e., crude oil and natural gas) and emit GHGs, contributing to climate change. Furthermore, plastics break down into persistent remnants—microplastics and nanoplastics, which found throughout the environment [50].

Plastic pollution also has direct ecological impacts. For example, certain plastics (PET, PS, PVC) are denser than seawater and tend to sink, accumulating on the seabed [51]. Benthic (seafloor) organisms and sensitive habitats like coral reefs can be suffocated or physically damaged by this submerged debris [51,52]. Since plastics persist for centuries, wildlife are often exposed, where animals can become entangled in larger plastic debris or ingest it, leading to suffocation, starvation, or death. These marine impacts are exacerbated in regions where plastic waste management (reduction, reuse, recycling) is lacking.

Today, microplastics have been found within food chain. Many fish and other seafood species show traces of ingested plastic, which implies that humans could be exposed though consumption [5,53]. Furthermore, microplastics are also found in soil and freshwater environments, where they can affect agriculture (e.g., soil health) and freshwater organisms. It is estimated that 4.8–12.7 million tons of plastic waste enter the oceans each year, breaking down into about 5.25 trillion microplastic pieces now floating in the seas [54]. Laboratory and field studies have linked microplastic exposure in wildlife to issues such as impaired reproduction, digestive tract blockages, stunted growth, and false satiation (organisms feeling ‘full’ without nutrients) [55]. Plastic debris has measurable impacts: for example, Denuncio et al. (2011) [56] documented fatalities in marine organisms (e.g., dolphins) due to plastic ingestion. Due to their feeding habits, filter-feeding organisms like oysters and mussels tend to accumulate microplastics; thus, they have been proposed as biological indicators of microplastic pollution in marine environments [57]. Microplastics poses hazards in both marine and freshwater ecosystems. High concentrations of microplastics have been found in freshwater environments globally Pauly (1998) [53], with sources and impacts similar to those in oceans. The extent of adverse effects on freshwater fauna is still under study and subject to debate [58]. The impacts of microplastics on health (in wildlife and humans) have also been investigated. Studies over the past decades suggest that microplastic particles can evade bodily defense mechanisms and accumulate in respiratory tracts—reaching deep into the lungs of animals or humans—potentially causing inflammation [5,53]. Incidentally, microbial strains capable of degrading microplastics have been identified in freshwater and marine studies, suggesting a potential avenue for remediation. They also pose risks to soil ecosystems; they hinder soil organisms (i.e., earthworms) and plant growth in experimental settings. The full extent of microplastic contamination in soils, its ecological consequences, and effective interventions remain uncertain and are an active area of research.

It is important to note that LCA and EIA themselves do not prescribe solutions; they are evaluation frameworks (per ISO standards) that support understanding the environmental, social, and economic implications of products or policies. These science-based tools reveal the benefits and drawbacks of certain CE approaches and indicate cases, where keeping materials in circulation longer might be counterproductive if contamination removal is too costly or resource-intensive [48]. Insights from LCA/EIA analyses have informed the development of various sustainability strategies to address the challenges identified.

5. Plastic Waste Management Strategies

Single-use plastics are an obstacle to implementation of CE in plastics. Replacing single-use plastic with other materials in a CE poses challenges and can increase overall economic costs. The initiative to reusing single-use plastic increase plastic waste and pollution, thus limiting circularity [59]. In response, the plastics industry has implemented various waste management strategies to mitigate plastic pollution. The two primary sustainability approaches have been: (1) the Reduce/Reuse/Recycle (3R) strategy, and (2) the adoption of bioplastics as alternatives to conventional plastics. These strategies tend to have relatively low impact on production processes and costs, but so far have yielded only partial environmental benefits [59]. Additionally, there is a potential of adopting plastic offsetting strategy (analogous to carbon offsetting) to address the global impacts of plastic waste.

5.1. Reduce & Reuse Strategies

Upstream reduction (actually producing and using less plastic) is often not favored by plastics manufacturers, as it directly cuts into material demand and production volumes. Various studies explore reducing plastic consumption by substituting other materials—for example, using wood- or bamboo-based bioplastics, or non-plastic alternatives like glass, steel, or silicone, which can, reduce overall waste generation [19]. Life Cycle Assessments suggest that certain bioplastic alternatives may not necessarily be more beneficial in terms of end-of-life impacts. For instance, Hottle et al. (2017) [60] compared compostable bioplastics vs. conventional plastics (PET, HDPE, LDPE) and found that recycling conventional plastics had a lower global warming impact than letting bioplastics decompose (releasing methane in landfills). Among waste management methods, such as reuse, which involves using products or materials again for their original or new purposes, especially effective in reducing waste generation. For example, consumers might repurpose plastic containers for storage or reuse plastic bags as liners or covers around the home [35]. In practice, however, the rates of reuse (and reduction) remain very low in the plastics industry. Khan et al. (2020) [35] found that only about 14% of plastic waste is being reused, and that around 23% of potential waste is being avoided through reduction efforts. This indicates that most organizations are not yet prioritizing reuse and reduction, thereby limiting progress toward CE.

5.2. Recycling Strategies

Recycling is currently the most pursued waste management method for plastics (more so than reducing or reusing), where the plastic sector deploys several recycling approaches. Various studies have been conducted on recycling; however, global recycling rates for virgin plastics have remained only 9–10%, indicating that more needs to be done [7]. The predominant method is mechanical recycling—physically reprocessing waste plastic into new products without altering its polymer structure. Mechanical recycling is widely used for materials like polyolefins (e.g., melting and remolding plastic into items such as garbage bags and auto parts) [47]. Another approach is chemical recycling, which breaks down plastic at the molecular level. This process alters the chemical structure of the polymers, for instance, converting them into monomers or other chemicals that can serve as feedstock to synthesize new polymers [27]. Composting could be considered a form of chemical/biological recycling for biodegradable plastics: under high heat (thermophilic conditions), organic bioplastics can decompose into biomass, water, and CO₂ [61]. Chemical recycling is still in its early stages—it is technologically complex and capital-intensive, as such it is currently the least commonly used option [62]. A further category considered is energy recovery (recovering energy through controlled incineration of plastics). While not recycling in the traditional sense, it does reclaim energy and reduce landfill volume. The main advantage of energy recovery is diverting waste from landfills (crucial where landfill space is limited) and generating electricity or heat. Setting up modern waste-to-energy incinerators requires significant investment in pollution-control technology, and such projects often depend on government incentives or support due to economic and regulatory factors [61].

Innovative recycling processes are being implemented; for instance, used PET bottles can be shredded into flakes and spun into polyester fibers for textiles or mats. Some plastics can undergo chemical treatment to be broken down to monomers and re-polymerized—CPChem’s Marlex^® Anew is one example of polyethylene produced from such recycled feedstock [63].

Another example, in terms of mechanical recycling, an LCA study in China found that in the mechanical recycling process, the extrusion step had the highest environmental impact, followed by the implications of using fillers/additives [64]. Overall, however, mechanically recycled plastic had roughly four times less environmental impact compared to producing virgin plastic. Another LCA compared different end-of-life routes for PET: mechanical recycling, chemical recycling, and energy recovery. It concluded that both mechanical and chemical recycling options dramatically reduced emissions of key pollutants compared to incinerating PET for energy, with recycling having the lowest environmental impact among the options [65,66]. Liu et al. (2022) [67] studied recycling of medical plastic waste in China and found that it reduced emissions by about 0.76 tons CO₂eq per ton of waste compared to disposing of that waste and producing virgin material instead. They noted that the emission savings from recycling such waste would increase each year as recycling processes improve. The study, amongst others such as Hottle et al. (2017) [60]) highlight the importance of local factors—such as transportation distance and sorting efficiency—in determining the benefits of recycling over other options like composting or landfilling. Costa et al. (2021) [20] evaluated the simultaneous recycling of plastic waste and Carbon Capture and Utilization (CCU) strategies in the manufacturing of other value-added products, such as olefins, to reduce fossil fuel consumption. Others such as Shamsuyeva and Endres (2021) [37] considered existing recycling technology and end-of-life options, indicating that mechanical recycling is the most feasible recycling strategy for the industry to support the development of quality recycled plastics. while Al-Thani et al. (2022) [66] considered a case study in Qatar for PET recycling technologies, showing that closed-loop recycling, which recycles the product without losing its properties or causing material degradation, is one of the ideal options compared to other technologies.

Notably, while the benefits of recycling are evident, there are challenges related to feedstock management and quality control, amongst others. For instance a case study on recycling HDPE into new plastic pipes found that managing the consistency and quality is challenging when the feedstock is sourced from mixed waste streams (handling, sorting, and selecting compatible plastic types are required to meet specifications) [68].

5.3. Bioplastics Strategy

Bioplastics—plastics made from renewable biological raw materials—totaled 2.11 million tons in 2018 and many experts argue that a transition to sustainable plastics will require shifting to renewable feedstocks and integrating material recycling incorporating CE principles into plastics production [69]. They emphasize that product design should be integral to the development of bioplastics, to ensure these new materials perform well and can be recycled effectively at end-of-life. Current research indicates that certain types of bio-based building blocks (especially aromatic or long-chain monomers) are not being prioritized by industry, likely due to challenges such as low productivity, difficulties in fermentation or synthesis (solubility and transport issues in cells), toxicity, and complex production routes [70]. One promising development is the advent of polyhydroxyalkanoates (PHAs), which arebio polyesters produced by certain microbes and could be a significant step toward large-scale bio-based plastic production [70]. To realize the potential of bioplastics, substantial efforts are needed in biotechnology and process engineering. This includes developing robust production platforms (microbial hosts with the necessary genetic modifications and bioprocess technology) to boost yields and energy efficiency, as well as protein engineering of enzymes to synthesize or degrade polymers more efficiently [71,72]. Such advances would likely operate within integrated biorefinery setups, which arefacilities that convert biological feedstocks into multiple products (fuels, chemicals, materials)—to maximize resource use. Moreover, minimizing the environmental footprint of plastics will require diversifying feedstocks (using waste biomass, biogas, etc., to avoid land-use impacts) and powering production with renewable energy [71,72,73]. The shift from fossil-based plastics to bioplastics is not feasible, as mass-producing bioplastics would still not meet global plastic demand [70]. Therefore, a portfolio of solutions and strategies are needed to achieve plastic sustainability goals.

5.4. Carbon Offsetting Strategy

The concept of carbon offsetting (aiming for carbon neutrality) began gaining attention in the early 1990s. By around 2009, research publications on carbon offsetting increased rapidly [14], reflecting growing concern over global carbon emissions and interest in market-based emission reduction tools [74]. This surge was also driven by increasing support from governments and NGOs for carbon offset mechanisms. For instance, in 2008, the UN Environment Program (UNEP) launched the Climate Neutral Network (CNNet), which brought together various organizations and governments in a pledge to transition to low-carbon operations. This initiative highlighted the momentum behind carbon neutrality at the time. The Kyoto Protocol (adopted in 1997, in force in 2005) laid the foundation by setting binding GHG reduction targets (on average, 5% below 1990 levels for developed countries) and by introducing market-based mechanisms to meet them (

Table 2. Kyoto’s market-based mechanism description.

Market-Based Mechanism	Description
International Emission Trading Mechanism	Each country under the Kyoto Protocol is allowed to emit into the atmosphere; under the emission trading mechanism, certain countries with spare assigned amount units (AAUs) can sell them to countries that exceed their AAUs.
Clean Development Mechanism (CDM)	Each country under the Kyoto Protocol can implement an emission reduction project in a developing country. These projects can be certified emission reduction (CER) credits equivalent to a ton of ${\mathrm{CO}}_2.$ Since 2006, 1650 projects were registered, totaling an expected 2.9 billion tons of ${\mathrm{CO}}_2.$
Joint implementations	Each country under the Kyoto Protocol can earn emission reduction units (ERUs) from an emission reduction project in another country to meet its target. The joint projects must reduce emissions by source or remove ${\mathrm{CO}}_2$ by enhancing sinks.

) [14]. In 2012, the Doha Amendment extended Kyoto with a second commitment period (2013–2020) and more ambitious targets (overall 18% reduction), further cementing mechanisms like emission trading and offset projects as key tools [14].

In essence, the Kyoto mechanisms established the blueprint for carbon offsetting—compensating emissions in one place by achieving reductions elsewhere. Companies use carbon offsets to support emissions-reduction projects (e.g., reforestation, renewable energy, waste-to-energy, community climate projects) and thereby neutralize their own emissions. Such offsets aim to curb the accumulation of GHGs in the atmosphere, mitigating climate change risks. In addition to direct offset projects, complementary policies, such as carbon taxes and emissions trading schemes are key tools in reducing overall carbon emissions [75]. Linking carbon-market architecture to plastic offsetting provide credibility to plastic offsetting mechanism to be implemented to define unit of account, credited activities assessed against a baseline, monitoring/reporting/verification (MRV) by independent auditors and registries to track issuance and retirement to reduce double counting risks. The Kyoto Protocol’s market-based mechanisms provide a template for the plastic offsetting architecture and credibility for decision making support.

5.4.1. Carbon Neutrality & Carbon Sinks

Carbon neutrality is achieved when any carbon emission released is balanced by an equivalent amount being removed (e.g., via carbon sinks), or when, emissions are eliminated entirely) [76]. However, still, it is important to note that carbon-neutral and net-zero are often used synonymously, although there is a subtle difference. Carbon-neutral usually means any remaining emissions are offset so that total emissions = 0. In contrast, net-zero carbon implies that no carbon emissions were produced in the first place, so there is nothing to offset. For instance, a facility running entirely on solar power with no fossil fuel use could be considered ‘zero carbon’ since it does not emit ${\mathrm{CO}}_2$ during operation, although there may be an embodied carbon emission that should be considered [76].

Companies have two options to achieve carbon neutrality: drastically cut their own ${\mathrm{CO}}_2$ emissions to (or near) zero, or offset those emissions by purchasing carbon credits (investing in external emission-reducing projects) [76]. In practice, organizations often start by calculating their carbon footprint (using standard carbon accounting tools or LCA) to understand how much they emit and source of emissions. Companies can then target the most significant emission sources for reduction and offset the remainder [14]. Since achieving zero-carbon emissions is challenging, carbon offsetting is a realistic way to achieve carbon neutrality. In addition, the cash raised through carbon offsets will support the deployment of low-carbon technologies in areas most vulnerable to the effects of climate change [14].

5.4.2. Carbon Offsetting Case Studies

Carbon sinks play a pivotal role in offsetting, as they increase the potential to utilize projects that enhance carbon sinks or invest in carbon capture projects. The natural sinks—mainly forests, soils, and oceans—absorb an estimated 9.5–11 Gigatons (Gt) ${\mathrm{CO}}_2$ per year, according to EU Commission data. Urban green spaces and agricultural practices are part of the carbon sequestration efforts. Park and Jo (2021) [77] conducted an LCA of urban parks in Korea, finding that while urban parks can act as carbon sinks, their net impact is influenced by design factors such as vegetation density and impervious surface coverage. The study highlighted that tree planting, reducing grass cover, and using eco-friendly materials enhance sequestration, a strength in providing actionable design guidelines. A limitation is the lack of specific measurement tools for carbon sinks in urban green spaces, which leaves room for variability. Wu et al. (2024) [78] complemented these findings by analyzing the carbon offset potential in the Beijing–Tianjin–Hebei area, recommending optimized industrial structures and low-carbon lifestyles to offset urbanization impacts. Wu’s regional focus on carbon sinks and emissions control offers broader applicability but lacks empirical, ground-level data on urban green policies.

In agriculture, Wu et al. (2022) [79] used LCA to assess emissions from maize production, noting that practices like returning crop residues to fields and using clean energy can reduce emissions- essentially making maize cultivation a potential carbon sink. Dong et al. (2022) [80] found that replacing conventional polyethylene mulch with biodegradable alternatives decreases emissions by 22.6%, though biodegradable mulch’s life cycle emissions remain a limitation. Collectively, these studies underscore the potential of targeted land-use strategies such as carbon sinks, though limited comparative data on crop-based sequestration challenges direct application.

Carbon pricing governs carbon emissions while funding projects that optimize carbon efficiency. Lee and Lee (2021) [81] explored carbon pricing as a potential revenue stream for emission management in U.S. higher education institutions, with findings suggesting that setting a $40 per ton carbon price could generate funds for sustainability projects. The hypothetical benefits include reductions in emissions and reallocation of resources. However, the study’s limitation lies in the scarcity of data on the actual implementation and outcomes of carbon pricing in higher education. Wu and Xu (2024) [78] further examined carbon pricing within urban contexts, indicating that emission control at the industrial level, combined with carbon offset incentives, could be economically viable. However, cost constraints and regulatory barriers remain unaddressed.

Waste valorization is a critical trend for achieving carbon neutrality, with multiple studies investigating the conversion of plastic waste into valuable resources as shown in

Table 3. Comparative summary of waste valorization technological pathways discussed in this review (advantages, limitations, scalability, and environmental trade-offs).

Technological Pathway	Main Outputs	Advantages	Limitations	Scalability Considerations	Environmental Trade-Offs
Landfill-derived alternative fuels (AFs) in cement production	Alternative fuels used in cement production	Reported 7.2–12.7% reduction in GHG emissions	Limited application in Canada due to cost and regulatory factors	Broader deployment constrained by economic feasibility and regulatory acceptance	Benefits are conditional on policy/economics; no additional impact categories quantified in this manuscript excerpt
Plasma pyrolysis & microwave-assisted activation	Syngas, slag, activated carbon	Demonstrates technological feasibility of converting plastic waste to valuable products; framed as minimal CO2 emissions	High energy demand; need for extensive infrastructure	Scaling constrained by energy intensity and infrastructure availability	Trade-off between “minimal CO2” framing and the burden associated with high energy demand and infrastructure requirements
Gasification systems (including CHP and two-stage)	Syngas for energy; CHP yielded 300 kW; two-stage adjusts H2/CO2 ratios for higher-value fuel	CHP system reported reduced emissions, successful demonstrations; improved fuel quality potential (two-stage)	Scalability remains a key limitation	Practical constraints include energy use and economic feasibility	Environmental gains depend on deployment conditions; trade-off implied via energy and cost constraints

[82,83,84]. Pitre et al. (2024) [82] assessed the use of landfill-derived alternative fuels (AFs) in cement production, finding a 7.2–12.7% reduction in GHG emissions. However, the limited application of AFs in Canada due to cost and regulatory factors constrains their broader use. Mukherjee et al. (2024) [83] and Dan et al. (2024) [84] explored advanced processes like plasma pyrolysis and microwave-assisted activation to convert plastic waste into syngas, slag, and activated carbon. While these studies highlight the technological feasibility of waste-to-energy conversion with minimal CO₂ emissions, they also highlight limitations, including high energy demands and the need for extensive infrastructure.

Comparatively, Li et al. (2024) [85] and Zou et al. (2024) [86] implemented gasification systems to repurpose plastic waste into syngas for energy. Li’s Combined Heat and Power (CHP) system yielded 300 kW and reduced emissions, while Zou’s two-stage system adjusted H₂/${\mathrm{C}\mathrm{O}}_2$ ratios for high-value fuel. Despite successful applications, the scalability of these methods remains a key limitation. Collectively, these studies reveal the strengths of waste valorization in advancing CE principles, though practical challenges such as feedstock supply, and economic feasibility persist [85,86]. Furthermore, any offsetting initiative must be transparent and involve local populations. Emphasis is being placed on researching several pathways to reduce carbon emissions, such as biomass production and the commodification of ecosystem services. This represents a more socio-economic approach, whereas earlier research on carbon offsetting often focused on theoretical fundamentals (e.g., the carbon sequestration potential of forests, the concept of embedded carbon, or market uncertainties) [87].

5.4.3. Towards Plastic Offsetting

Various strategies are being used to mitigate plastic pollution—from outright bans to improved waste management and even offset-like programs—but major challenges persist. For instance, Chen et al. (2022) [88] found that incineration and pyrolysis, while recovering energy, are energy-intensive and emit more GHG. Chen et al. (2022) [88] also evaluated China’s initiatives toward plastic recycling and illustrated that, despite the complexities of waste management strategies, such as the 2018 ban on plastic imports, recycling did not improve, as China still incinerates or landfills much of its plastic waste. Lee and Lee (2021) [81] examined the global waste trade market and found that, while China bans the import of waste, the United States continues to export waste to countries with limited waste management capacity, complicating international climate agreements such as the Kyoto and Paris agreements. Wen et al. (2023) [89] estimated that optimizing recycling practices could cut emissions by 13,000–27,000 tons of ${\mathrm{C}\mathrm{O}}_2$ eq per year. Most advanced systems are in developed countries, while plastic waste generation is rising in regions lacking infrastructure [80].

Dijkstra et al. (2021) [90] considered small and medium businesses and their contribution to marine plastic waste challenges. They found that startup projects for collections, transformation, and monitoring can reduce plastic pollution, especially in developing countries. These startups, collaborating with standardization and transparency to measure the impact on marine waste, would minimize waste. They also reiterated that it is crucial to engage communities and governments to address marine plastic pollution. Dijkstra et al. (2021) [90] work supports the concept of plastic offsetting which is a novel waste management strategy in which a plastic producer sponsors a projects to reduce the impacts of plastic waste in another geographical location where plastic waste is generated and waste management strategy cannot be financed. This approach can address plastic waste and suggest a new pathway for global waste management.

5.4.4. Plastic Offsetting: A Potential Strategy

While the peer-reviewed literature explicitly focused on “plastic offsetting” remains limited and fragmented, and based on the limitations that other plastic waste management strategies are facing, plastic offsetting, inspired from carbon offsetting, can be an alternative strategy to the existing plastic waste management systems, and can be considered plastic waste management from a global lens rather than a local perspective alone.

The notion of plastic offsetting compared to plastic footprint, plastic credit and neutrality is shown in

Table 4. Plastic footprint, offsetting, credit and naturality definitions.

Term	Definition
Plastic footprint	The plastic waste generated that is affecting the environment
Plastic offsetting	Balancing plastic footprints by sponsoring projects to eliminate plastic waste elsewhere
Plastic credit	The plastic units that are tradable in markets to balance plastic footprint
Plastic neutrality	Equalizing plastic use with equivalent plastic credit to claim net-zero footprint

. In general terms, plastic offsetting allows plastic producers or consumers to offset the plastic produced or consumed by sponsoring a project to remove equivalent plastic waste in a region where plastic waste is mismanaged. For example, a company in the one country producing 1 million tons of plastic annually can sponsor a recycling facility in another country to collect and recycle 1 million tons of plastic waste from oceans and rivers, removing 1 million tons of mismanaged plastic from the global ecosystem.

Hence, a plastic offsetting framework consisting of a proposed Conduct–Develop–Select–Re–Evaluate (CDSR) framework steps may be studied and evaluated as a potential waste management strategy (Figure 4). It can include the following steps:

• Step 1: Establish a baseline of environmental impact from virgin plastic production (via an LCA) to measure the status quo.
• Step 2: Develop a scoring mechanism based on the LCA results to quantify plastic impacts (analogous to a carbon footprint score, but for plastics).
• Step 3: Select an offsetting project that will be funded to reduce plastic waste (e.g., sponsoring a beach cleanup in a high-leakage region) as an intervention.
• Step 4: Re-evaluate the LCA after offsetting to calculate the improved score and quantify the waste reduction benefit achieved.

This proposed framework will set the standard for the plastic offsetting strategy that will complement the existing waste management strategies. Various articles stipulated that carbon offsetting, similarly plastic offsetting, may indicate that the plastic industry will not focus on reducing plastic production and may even increase it; therefore, governments and the plastic industry should collaborate to reach a consensus on realistic targets to eliminate plastic waste not only on a national level, but also on the international levels. Unlike carbon offsets, which target emissions, plastic offsetting would specifically target plastic waste streams—providing a direct mechanism to invest in waste collection and recycling infrastructure in regions that need it the most.

In order to translate the CDSR concept into implementable plastic offsetting and to ensure a clear plastic offsetting mechanism it is necessary to evaluate and incorporate aspects from project design, third-party validation, registration under a standard, monitored implementation, independent verification, and credit sale/transfer. Plastic credit programs might be emerging under independent standards and registries nowadays that require further evaluation. Learning from carbon credits, integrity risks must be acknowledged to reduce greenwashing, resulting in minimum requirements such as registering of credit cycle, avoiding double counting, shifting waste burdens to others, and verification of end-of-life post offsetting. Future studies need to address a comprehensive evaluation of plastic offsetting and the outcome of conducting that to the global reduction in mismanaged plastic.

6. Conclusions

Plastic production has risen in tandem with global GDP, although this growth has exacerbated plastic litter and its environmental impacts. While various firms in the plastics industry have pledged sustainability initiatives such as the 3Rs, bio-based plastics, and carbon neutrality, these efforts fail to address the root causes of plastic waste accumulation, particularly in regions with underdeveloped waste management infrastructure. The following gaps emerge from a review of the existing literature:

• Insufficient progress of the existing waste management strategies: reduce, reuse, recycle, and bioplastics cannot cope with the increased production of virgin plastics and the increase in the accumulation of waste.
• Geographic disparity in waste management: Most sustainability efforts, including recycling and CE initiatives, are concentrated in developed countries. Plastic pollution is growing in developing regions due to inadequate waste management systems, contributing significantly to global plastic leakage into oceans and rivers.
• Inadequate focus on offsetting: While carbon offsetting mechanisms are well-established and widely studied, there is limited research on implementing similar strategies for plastics. There is no comprehensive plastic offset mechanism proposed or tested that links plastic production in developed regions to waste reduction investments in developing regions.
• Insufficient metrics and standardized methodologies: Research lacks standardized methodologies tailored to evaluate the environmental, social, and economic impacts of plastic. There is a need for robust metrics to measure initiatives in reducing plastic waste and mitigating environmental burdens, while considering social and economic aspects. For example, its potential to fund waste management infrastructure, create jobs, and support the sustainable growth of local economies in high-need areas remains underexplored.
• Policy and framework deficiencies: Existing policy frameworks do not provide adequate support for the implementation of plastic—setting unrealistic targets at national or international levels. There is limited guidance on how such mechanisms could complement existing waste management strategies
• Integration of plastic offsetting with CE initiatives: The literature has not sufficiently explored how plastic offsetting could be integrated into CE strategies to achieve dual benefits of waste reduction and economic growth in developing regions. Studies often treat plastic offsetting and CE as separate concepts, missing the opportunity for synergistic solutions.
• More research needed: Additional research is needed for developing plastic footprint accounting rules and system boundaries that reflect polymer heterogeneity and leakage risk; testing polymer mass-based units as a cornerstone for further environmental scoring; establishing robust baselines; and empirically evaluating whether plastic credit finance materially improves waste management outcomes without incentivizing continued growth in virgin plastic production.

Addressing these gaps and future work through standardized metrics, supportive policies, integrated strategies, and research on plastic offsetting effects could significantly strengthen global efforts to manage plastic waste. Plastic offsetting, in particular, represents a novel and promising tool to complement existing approaches, helping balance plastic production with waste mitigation in a globally equitable way.