Developing Traceability Systems for Effective Circular Economy of Plastic: A Systematic Review and Meta-Analysis

Abstract

Annually, the global plastic waste generation adds up to over 353 million tonnes, which is associated with substantial environmental and societal issues, such as microplastic pollution and landfill management. Despite many attempts to integrate sustainable circular economy strategies into the plastic industry, several challenges have resulted in material loss and poor-quality recycled products. To address these challenges, this study proposes a material traceability system to overcome the issue of flawed recycling of plastic. The authors employed a systematic literature review and meta-analysis to summarise the current state of traceability in the plastic recycling industry. The results revealed that blockchain technology is the most promising framework amongst various traceability systems; however, its implementation is hindered for three reasons. First, future systems must prioritise interoperability to ensure seamless integration; second, standardisation is imperative for effective traceability; and third, implementing digital and physical traceability is essential to maximise the value of materials by enabling improved material identification and enhancing sorting efficiency. Further, it emerged that integrating quality control into traceability solutions is essential for improved recycled content in plastic products. By shedding light on these insights, this study contributes to developing traceability systems in the plastic recycling industry, guiding policymakers, industry practitioners, and researchers alike. Ultimately, the implementation of effective traceability mechanisms has the potential to drive plastic circularity by improving material identification, sorting practices, and overall transparency within the industry.

1. Introduction

According to the Organisation for Economic Co-operation and Development [1], plastic represents more than 17% of the total waste yearly [1]. Projections show that societies will triple their plastic waste generation by 2060, with a consequent increase in related waste from 353 million tonnes in 2019 to 1014 million tonnes in 2060. In 2019, 49.21% of waste was landfilled, 22.45% was mismanaged, and 19.05% was incinerated [2]. However, only 9% of this waste was recycled in 2019, and the plastic recycling rate is projected to increase to only 17% by 2060 [3]. The accumulation of plastic in landfills also takes up valuable space and contributes to long-term environmental degradation [4]. Furthermore, the sheer volume of plastic waste generated means that landfills alone cannot sustainably manage this material. Incineration is another method used to manage plastic waste, which involves burning plastics to reduce waste volume and sometimes generate energy. While incineration can decrease waste accumulation, it has significant environmental drawbacks. The process releases greenhouse gases, toxic chemicals, and particulate matter into the atmosphere, contributing to air pollution and climate change [5]. Although some facilities use advanced filtration and capture methods, incineration remains controversial due to its health and environmental impacts. Uncontrolled plastic waste is improperly managed waste and often ends up in natural environments, including oceans, rivers, and urban areas. This issue is particularly severe in regions lacking adequate waste management infrastructure [4,5]. Uncontrolled plastic waste leads to marine pollution, harms wildlife, and disrupts ecosystems. It also exacerbates microplastic pollution, which affects food chains and poses health risks to humans and animals. Among the scrutinised plastic streams, waste from the packaging industry is one of the most prominent sources, and its sustainable management requires the development and implementation of new policies and circularity models worldwide [6]. The traditional method of recycling plastics by shredding, melting, and reforming them faces challenges that limit its effectiveness. Contamination, polymer degradation, and the complex sorting requirements for mixed plastics contribute to low recycling rates [7]. To address these challenges, emerging technologies such as chemical recycling are gaining attention that can complement mechanical recycling [7]. Chemical recycling breaks down plastics into their essential molecular components, allowing them to be rebuilt into new, high-quality plastic products. Unlike mechanical recycling, chemical recycling can process contaminated and mixed plastic waste more effectively, potentially increasing recycling rates and the quality of recycled products [7].

An effective circular economy (CE) is inextricably linked to effective recycling operations, and its applications must be implemented to alleviate recycling operation challenges and vice versa [8]. Against this backdrop, this study explores material traceability systems that could represent a solution to the limited recycling of waste plastic. Specifically, traceability systems are considered paramount in closing supply chain loops, thus contributing toward a circular economy of products and consequent reduction of waste. Although such systems are becoming increasingly popular, as they provide transparency and visibility from goods production to their end of life and information about the sourcing of materials, there is limited knowledge on how quality in plastic recycling is traced to ensure its quality. All the targets of recycled content and the recycling claims made by plastic products industries and recyclers need to be assessed and traced.

Traceability systems are integral components within various industries, providing means to track and monitor the movement of products, materials, or information throughout their supply chain lifecycle. Traceability is often used as a means of quality control and identifying defects in products. However, the application of such a system in the plastic industry is very limited, which hinders its broad adoption in the recycling industry [9].

The core principles of a traceability system, as outlined in BS EN 15343, ISO 22095, and ISO 59004 [10,11,12], are fundamental to enhancing plastic recycling and effective material tracking. These principles: transparency, data integrity, material identification, process accountability, and chain of custody ensure that recycling efforts maintain accurate, consistent, and verifiable information throughout the lifecycle of plastic products, supporting a circular economy and sustainable waste management. Transparency is at the heart of traceability, as it provides visibility across every stage of a plastic product’s journey, from production through post-consumer waste and recycling. According to ISO 59004 [12], maintaining transparency ensures that stakeholders such as manufacturers, recyclers, and consumers can track materials at each point in the lifecycle. This transparency builds trust and enables more responsible management practices, reinforcing the goals of the circular economy by making recycling processes accessible and verifiable. Data integrity is essential for secure and reliable material tracking. BS EN 15343 [10] emphasises that information about recycled plastics’ composition, origin, and processing should be recorded accurately and maintained without alteration. This integrity guarantees that recycling processes are built on verified information, allowing each stage of the recycling lifecycle to rely on dependable data. In practice, any details logged about a plastic product’s origin, composition, or usage remain tamper-proof, strengthening the recycling framework’s reliability. Material identification is crucial in preventing contamination during recycling, as identified in BS EN 15343 [10]. Recycling facilities can sort and separate materials more effectively by ensuring that each plastic type, additive, and quality level is tagged or marked. This identification reduces waste and improves the quality of the recycled output, making it more viable for high-quality applications. Process accountability holds each participant in the recycling chain responsible for tracking handling, processing, and disposal actions, as specified by BS EN 15343 [10]. This accountability framework highlights areas where contamination or processing errors might arise, allowing for improved quality control. It ensures that each stakeholder adheres to environmental standards and regulatory requirements, contributing to a recycling process that is transparent and responsible. Chain of custody is critical to establishing an unbroken, traceable record of ownership and handling, as BS EN 15343 and ISO 22095 outline [10,11]. This continuous tracking prevents mismanagement of materials, ensuring they are not lost, improperly disposed of, or mishandled. The chain of custody allows brands to verify claims about recycled content, giving assurance that plastics labelled as ‘recycled’ genuinely originate from certified recycled sources. These core principles of transparency, data integrity, material identification, process accountability, and chain of custody form a comprehensive framework for improving plastic recycling through traceability. ISO standards establish a robust foundation for these practices, helping to make material tracking more efficient and reliable, enhancing the quality and usability of recycled materials, reducing contamination risks, and promoting accountability across the entire supply chain. By following these principles, traceability systems support a circular economy and lead to more sustainable plastic waste management.

Global Traceability Standard [13], known as GS1, provides a foundational methodology for organisations to design traceability systems tailored to their unique requirements and objectives. The core concept of GS1 is to create a global standard for supply chain traceability, enhancing visibility and data accuracy. This is essential for engaging diverse stakeholders such as businesses, governments, NGOs, and consumers. For instance, businesses utilise GS1 standards to enhance supply chain transparency and efficiency, which is crucial for tracking materials like recycled plastics. Governments leverage these standards to ensure compliance with environmental regulations and foster a circular economy. Additionally, standardising traceability information allows consumers access to trustworthy data regarding product origins and recycling processes [14].

The GS1’s framework is a basis for developing sector-specific, regional, and local standards for implementing integrated waste management practices (see Figure 1). Efficiencies are identified by standardising data collection and sharing, facilitating waste prevention and reduction. These clear standards are instrumental in sorting, tracking, and verifying recycled content, thus improving recycling rates and material quality. GS1 standards also support consistently identifying traceable objects, including products, materials, and components, enhancing data sharing about their movements and transformations across various stakeholders. This consistency fosters effective cross-sector collaboration, essential for recycling and material recovery initiatives, and facilitates the integration of technologies like the Internet of Things (IoT), artificial intelligence (AI), and blockchain, improving material visibility and tracking.

Moreover, GS1’s reliance on proven standards helps prevent fragmented approaches, simplifying its adoption and scalability across diverse industries and sectors. This interoperability allows various systems and technologies to work together seamlessly, which is crucial for widespread adoption and promoting sustainable practices throughout the supply chain.

A traceable object is defined as a physical or digital item requiring information about its history, application, or location, ranging from consumer goods and medicines to logistic units and assets like vehicles and equipment. Traceable objects are identified at different levels: class level distinguishes by product ID, batch/lot level adds specific batch numbers, and instance level assigns unique serialised IDs. The selection of identification level depends on the traceability system’s goals and the nature of the supply chain, where high-risk products are identified more precisely.

In supply chains involving multiple organisations, traceability data are generated as goods moved from one entity to another, documenting who, what, where, when, and why at each stage. This comprehensive tracking ensures transparency and accountability throughout the supply chain, highlighting the need for standardised traceability data across different organisations.

Organisations must design traceability systems that support various applications such as risk management, efficiency, compliance, sustainability, and consumer trust. These systems should leverage existing technologies and integrate seamlessly with new components, ensuring they are adaptable to evolving needs. However, these systems often require a common standard to ensure interoperability across different supply chain actors, highlighting the necessity for standardised data and identifiers.

Sharing traceability data among supply chain partners can be approached in several ways: locally within each organisation, centrally through a shared repository, cumulatively pushing data forward along the supply chain, decentralised with blockchain technology, where each partner keeps a copy, or networked, allowing comprehensive access to data. Each method caters to different needs and scenarios, illustrating the versatility and complexity of implementing effective traceability systems.

The Australian Traceability Framework provides a regional approach to enhancing traceability systems across various industries [15]. This framework aims to ensure consistent expectations and support from the government while facilitating industry compliance. The guidelines established under this framework help businesses align their traceability efforts with national standards, promoting a more transparent and reliable supply chain. The following section will examine the specifics of the Australian Traceability Framework, its key capabilities, strategic objectives, and implications for businesses operating within Australia’s recycling and manufacturing sectors.

The Australian Traceability Framework is structured to enhance the robustness and reliability of traceability systems across supply chains, mainly focusing on recycled materials (

Table 1. Framework comparison.

Topic	GS1 Framework	Australian Framework
Scope and focus	Broad global framework for traceability across various industries and supply chains, not limited to recycled content.	Designed explicitly for recycled content within Australia, focusing on provenance, composition of recycled materials.
Interoperability	Sets the baseline for global interoperability without needing alignment with other frameworks.	Requires alignment with the GS1 Standard to ensure compatibility with global traceability practices.
Specialisation	Supports broad traceability but lacks a specialised focus on recycled content.	Provides explicit guidance for managing recycled content, emphasising provenance, composition, and quality.
Timeline	No specific deadlines, focusing on continuous best practices and standards.	Specifies a deadline for complete supply chain traceability by 2027.
Certification and verification	Advocates for data accuracy but does not focus on certification schemes related to recycled content.	Emphasises the need for certification schemes and verification processes to validate recycled content claims.
Legal compliance and record management	Provides general guidelines for data management, leaving legal specifics to local or industry regulations.	Requires adherence to legal obligations and a minimum record retention period.

). It emphasises interoperability by aligning traceability activities with the GS1 Global Traceability Standard, ensuring that systems can interact seamlessly across different platforms and international boundaries. The framework advocates for ‘One-step forward, One-step back’ traceability, mandating that all involved parties collect and share information that enables the tracking of materials one step upstream and downstream. Aiming for Full Supply Chain Coverage, the framework aims to trace all recycled content throughout the supply chain by the end of 2027. This comprehensive coverage is expected to include tracing the provenance of recycled materials back to their first recovery location. Additionally, mass balance or other methods are required to accurately determine the composition of recycled content as it moves through the supply chain. Quality assurance is another critical element, focusing on documenting processing methods and assessing associated risks to ensure the quality of the recycled content. The framework stipulates collecting and sharing minimum data elements, including detailed information on the composition, provenance, and quality of materials. Verification processes are outlined to confirm the accuracy and adequacy of the traceability information provided, supporting valid recycled content claims. Participants are also encouraged to integrate certification schemes that align with the framework’s standards to achieve traceability, further solidifying the system’s reliability. Finally, the framework mandates meticulous record management, requiring that traceability records be maintained for at least five years or as legal obligations dictate. This comprehensive approach aims to boost confidence in recycled materials, encouraging increased use in manufacturing and construction, thus supporting broader environmental and sustainability goals.

Figure 2 illustrates a conceptual framework for integrating pre-consumer and post-consumer stakeholders into a traceability system, using the GS1 and Australian traceability frameworks as foundational structures. It outlines the flow of materials and data from manufacturing stakeholders to the consumer, with a focus on tracking recycled content. However, the integration of consumers and IWMS into the broader traceability framework is not clearly addressed in the existing frameworks. This gap, particularly how traceability systems are integrated into IWMS for plastics, is highlighted as an area requiring further analysis. The literature review will explore how traceability systems are currently considered within IWMS, aiming to close this gap and provide a more comprehensive understanding of how post-consumer plastic waste can be effectively traced and managed within a circular economy framework. Governance plays a central role in managing data flows between stakeholders, but the need for further development in post-consumer traceability is evident.

The concept of zero waste challenges the traditional view of waste as something to be discarded [16], instead recognizing it as a valuable resource in transition. Zero waste aims to design and manage products and processes to systematically avoid and eliminate waste and pollution. Rather than focusing solely on end-of-life disposal, it emphasizes waste prevention, resource efficiency, and the continual reuse of materials, aligning with the principles of a circular economy. In this model, materials are kept in circulation for as long as possible through recycling, reuse, and regeneration. Waste is not seen as the end but as a phase in the lifecycle of a material that can be transformed into a new resource. This transformative view of waste redefines how society manages resources, aiming to eliminate the very concept of waste by ensuring that all materials are repurposed, regenerated, or re-enter the production cycle in some form, creating a closed-loop system.

At the core of traceability systems lies data capture technologies, which enable the collection of information about the items being tracked. Radio Frequency Identification (RFID) technology [17] offers wireless identification and tracking capabilities through RFID tags embedded within items, facilitating real-time data capture. Blockchain technology emerges as a disruptive innovation in traceability systems, offering immutable and transparent records of transactions [18]. By leveraging distributed ledger technology, blockchain ensures data integrity and authenticity, facilitating trust among stakeholders in complex supply chains. Each transaction recorded on the blockchain is secured, providing a tamper-resistant audit trail for tracing the provenance and movement of goods.

As plastic waste continues to accumulate globally, effective traceability systems offer a critical solution to improving recycling processes and supporting a circular economy. By providing a transparent and accountable way to track the journey of plastic materials through the supply chain, these systems help ensure that plastics are properly sorted, recycled, and reintegrated into the economy. This is not only essential for reducing environmental pollution but also for maximising resource efficiency and minimising the loss of valuable materials. Beyond waste management, the development of robust traceability systems has significant economic implications. For businesses, especially in industries reliant on plastics, implementing traceability systems can enhance supply chain transparency, build trust with consumers, and improve brand reputation. Companies that can prove the sustainable sourcing and recycling of their materials stand to gain a competitive advantage as the consumer demand for environmentally responsible products continues to rise. Furthermore, governments and regulatory bodies are increasingly setting stricter sustainability requirements, and businesses that adopt traceability technologies early will be better positioned to comply with future regulations. From an environmental perspective, the study’s focus on integrating technologies like blockchain to improve traceability is crucial for reducing the overall ecological footprint of plastic production and disposal. Traceability systems can help curb illegal dumping, reduce contamination in recycled materials, and promote more efficient resource use. By addressing these issues, the research contributes to the larger global effort to combat climate change and reduce waste, making it highly relevant in the current context of growing environmental concerns. Thus, the study is significant not only for its direct contributions to improving plastic waste management but also for its potential to drive systemic changes in how materials are tracked, recycled, and reused across industries. This broader impact underscores the need for innovation in traceability technologies, highlighting the critical role they can play in achieving environmental sustainability and economic growth. By making these connections explicit in the introduction, the study will more effectively engage readers and demonstrate the importance of the research.

This paper aims to contribute to the understanding of traceability systems in the plastic recycling industry, focusing on plastic packaging to foster the quality of recycled plastics and, hence, plastic recycled products. Thus, this study will investigate aiming to answer the following research question: How can traceability systems be effectively developed and implemented to improve plastic recycling within the context of a circular economy, and what are the key challenges and opportunities in integrating digital and physical traceability, particularly using emerging technologies such as blockchain? To address these questions, the paper adopts a systematic literature review (SLR) and meta-analysis (MA) methodology following the steps detailed in Section 2, categorising the substantial body of relevant literature and analysing related patterns and themes.

2. Methodology

SLR methodology is considered a comprehensive, reproducible, and rigorous approach, which allows the separation, identification, and reporting of results from the selected relevant literature [19,20]. For this study, the authors followed the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analyses; see Moher, Liberati [21] and PRISMA Checklist, Supplementary S1). Consistently, this SLR first unfolds in four steps (Supplementary S2), which allows to conduct the following meta-analysis (see Figure 3).

A key theme in the literature is the need for comprehensive traceability frameworks to accommodate plastic waste management’s complexity. This includes tracking the waste and the various processes it undergoes, such as sorting, recycling, and repurposing. The literature also discusses the potential of advanced technologies like blockchain, the IoT, and AI to improve the accuracy and reliability of traceability systems. However, it also points out the challenges of applying these technologies, particularly regarding data granularity, interoperability, and alignment with the existing standards.

In structuring our literature review, we have adopted the integrated waste management (IWM) concept as a guiding framework, rooted in its comprehensive approach to managing waste. This framework includes the collection, treatment, and disposal of materials through environmentally and economically sustainable methods. By integrating traceability within this framework, we aim to provide a holistic view of how traceability technologies and practices enhance waste management systems. This structured approach enables a thorough and nuanced discussion of the intersections between traceability and waste management, ensuring that our analysis remains focused and insightful. Integrated waste management is a well-established concept encompassing three primary categories: governance, supply chain waste stream, and enablers. Governance within integrated waste management involves the critical elements of monitoring, policy enforcement, and education [22,23]. These components ensure that waste management practices are regulated and informed, adhering to established guidelines and fostering public awareness and compliance. The supply chain waste stream represents the operational side of waste management, including the collection, treatment and disposal, transport, and the recycling or reuse of materials. This category focuses on the practical processes required to manage waste effectively, ensuring that materials are managed to minimise environmental impact and maximise resource recovery.

3. Results

The following section delves into the findings from our systematic literature review, critically examining the current landscape of traceability systems within plastic supply chain management.

As we will see, the literature on plastic waste traceability focuses on the challenges and methodologies of tracking plastic materials throughout their lifecycle. It highlights the importance of integrating digital and physical traceability methods to monitor plastic waste’s movement, transformation, and eventual disposal or recycling. The research examines the limitations of traditional waste management systems, which often operate linearly, and advocates for a shift towards circular integrated waste management systems. These systems aim to enhance the circularity of resources by combining waste and materials management, thereby reducing the consumption of natural resources.

This review highlights significant challenges in transitioning from traditional linear Integrated Waste Management Systems (IWMS) to circular Integrated Waste Management Systems (CIWMS). A primary challenge identified is the application of existing system analysis tools, which are typically designed for linear IWMS and may not adequately address the complexities of CIWMS. These tools can only partially capture the expanded boundaries necessary for a circular approach, which includes upstream subsystems that reflect the transformation of resources and their integration with waste management practices. This gap necessitates the development of enhanced analytical tools that can better accommodate the interconnected nature of CIWMS, thereby supporting more effective and sustainable waste management strategies.

Table 2. Integrated Waste Management framework analysis.

IWM Thematic		Number of Papers Related	Key Element
Physical stream of the supply chain	Waste prevention	23	Waste Prevention Through Improved Product Design, Circular Economy Principles, and Sustainable Practices Consumer Engagement and Incentive Mechanisms in Waste Prevention Challenges and Strategies in Managing Plastic Waste Sustainable Resource Management and Decarbonisation
	Recycling and reuse	33	Recycling and Reuse Strategies in Plastic Waste Management The Role of Technology and Market Mechanisms in Enhancing Recycling Efforts
	Waste collection and transportation	5	Automation and Efficiency in Waste Management Efficient Collection and Processing in Waste Management
	Treatment and disposal	8	Waste Recovery Strategies Treatment and Disposal Methods
Governance	Monitoring and enforcement	18	Traceability and Transparency in Waste Management Monitoring and Enforcement of Waste Management Practices
	Public education and engagement	3	Engaging Stakeholders through Policy and Fiscal Measures Educating and Engaging Stakeholders in Plastic Pollution Management
Digital Enabler	Technology integration	19	Integration of Advanced Technologies in Waste Management
	Digital traceability	37	Digital Traceability and Blockchain in Waste Management
Physical Enabler	Physical traceability	24	Material Flow Analysis and Physical Tracking of Plastics Advanced Technological Approaches for Traceability Integration of Physical and Digital Traceability Systems Advanced Technologies for Enhanced Traceability

presents a comprehensive analysis of various thematic areas within the Integrated Waste Management (IWM) framework, categorised under different supply chain and governance aspects. It maps out the focus of academic research across nine themes: waste prevention, recycling and reuse, waste collection and transportation, treatment and disposal, monitoring and enforcement, public education and engagement, technology integration, digital traceability, and physical traceability.

3.1. Physical Stream of the Supply Chain

Waste prevention is a critical component of sustainable waste management. It emphasises the importance of minimising waste generation at the source through better product design, adopting circular economy principles, and implementing sustainable practices. Various authors have explored these strategies, each contributing to a broader understanding of how to prevent waste effectively. Chaudhuri, Subramanian [24] mentioned circular economy initiatives that inherently involve waste prevention strategies, focusing on keeping materials in use for as long as possible and reducing the need for new resources. Similarly, Tomic and Schneider [25] discussed the EU’s aim to avoid waste production by embracing a circular economy model, which seeks to eliminate waste through systemic changes in production and consumption. Gorecki and Nunez-Cacho [26] advocated for replacing traditional linear production processes with closed-loop systems, aligning with waste prevention strategies that prioritise resource efficiency and sustainability. Giorgi, Lavagna [27] suggested improvements in circular strategies, emphasising the importance of better design and resource management to prevent waste and enhance product sustainability. Tang, Chau [28] highlighted advancements in green manufacturing and green design directly related to reducing waste through improved product design and resource utilisation. Milios, Christensen [29] identified deficiencies in product design that hinder recyclability and proposed measures for improving design practices to enhance recyclability and reduce waste. Chen, Yu [30] discussed a new design approach that reduces the need to replace barcodes and RFID labels, thereby decreasing resource waste and associated costs. This innovation exemplifies how thoughtful design can contribute to waste prevention by reducing the frequency of material replacement. Andrades, Martins [31] emphasised the need for improved waste prevention strategies to combat the unsustainable lifestyle and short-lived products contributing to marine debris. By addressing the root causes of waste, such as disposable products and overconsumption, these authors highlighted the importance of waste prevention in protecting the environment.

Consumer engagement and incentive mechanisms are vital for promoting waste prevention. They encourage individuals to adopt sustainable practices and make more environmentally responsible choices. By actively involving consumers and providing tangible benefits for reducing waste, these strategies help create a culture of sustainability. Esmaeilian, Sarkis [32] discussed how incentive mechanisms, such as tokenisation, can promote green behaviour among consumers and reduce waste generation. These mechanisms provide rewards or recognition for sustainable actions, motivating individuals to participate in waste prevention efforts. Colicchia, Creazza [33] focused on reducing food waste by engaging consumers with Supply Chain 4.0 technologies, which aim to improve sustainability in food supply chains. By providing consumers with better information and tools to manage their food consumption, these technologies help minimise waste and promote more sustainable food practices. Liu, Zhang [34] highlighted the plastic credit system, which encourages using products with higher recyclability, indirectly promoting better design and consumption practices. This system not only incentivises recycling but also drives the demand for products that are easier to recycle, supporting waste prevention at the consumer level.

Managing plastic waste presents numerous challenges, particularly in preventing environmental pollution and promoting sustainability. Various strategies have been proposed to address these difficulties, such as reducing plastic waste and improving waste management practices. Hsu, Domenech [35] highlighted the barriers to promoting plastic recirculation, which aligns with efforts to prevent waste through circular economy principles. By addressing these barriers, the authors suggested strategies to improve the efficiency and effectiveness of plastic waste management. Luan, Cui [36] aimed to provide a scientific basis for reducing the resource and environmental impact of plastic material metabolism. Their research implies a focus on preventing excessive resource use and waste generation. Their research emphasises the importance of understanding material flows to optimise resource use and minimise waste. Castillo-Díaz, Belmonte-Ureña [37] discussed using biodegradable plastics and regulatory measures to prevent environmental pollution and manage waste. Promoting the use of materials that degrade more easily and regulating waste management practices help to reduce the environmental impact of plastic waste. Courtene-Jones, Maddalene [38] highlighted the need for improved plastic waste management to protect marine and coastal resources, implicitly supporting waste prevention efforts. Their work underscores the importance of preventing plastic waste from entering the environment and harming ecosystems.

Sustainable resource management and decarbonisation are crucial for addressing the environmental challenges posed by traditional waste management systems. These approaches aim to reduce reliance on finite natural resources and lower greenhouse gas emissions, essential for mitigating climate change. Sankaran [39] discussed efforts to decarbonise energy systems and sustainably consume raw materials, highlighting the importance of reducing carbon emissions and optimising resource use to prevent waste. These efforts are integral to creating a more sustainable and resilient economy. Benmoussa [40] focused on optimising replenishment flows to mitigate or eliminate waste, directly aligning with waste prevention strategies. Improving the efficiency of resource use and reducing waste in supply chains contribute to a more sustainable approach to resource management. Ellsworth-Krebs, Rampen [41] advocated for framing packaging as an asset to prevent waste, using Digital Passports to track and manage packaging throughout its lifecycle. This approach reduces waste and supports the circular economy by keeping materials in use for as long as possible.

Recycling and reuse strategies in plastic waste management are crucial for advancing circular economy principles by reducing plastic waste’s environmental impact and extending the materials’ lifecycle. These strategies involve transforming plastic waste into valuable resources that can be reintroduced into production cycles, minimising the reliance on virgin materials and decreasing waste. Several authors have addressed various aspects of recycling and reuse strategies, highlighting the challenges and opportunities in enhancing these practices. For example, Chaudhuri, Subramanian [24] discussed the involvement of small- and medium-sized enterprises (SMEs) in recycling plastic waste to create innovative products, showcasing how entrepreneurship can drive recycling efforts. Gorecki and Nunez-Cacho [26] focused on adapting circular economy principles, emphasising the recycling and reuse of materials, particularly in bridge construction and decommissioning. Similarly, Giorgi, Lavagna [27] highlighted the need for the better implementation of recycling and reuse strategies in the construction sector, indicating the potential for significant waste reduction through improved practices. Luan, Cui [36] provided data on the proportion of recycled plastic waste, underscoring the importance of maintaining and improving recycling efforts to manage plastic waste effectively. Khadke, Gupta [42] focused on improving the efficiency of plastic recycling processes, aligning with efforts to recover and repurpose materials from waste, which is critical for reducing landfill usage and conserving resources. Furthermore, Chidepatil, Bindra [43] aimed to enhance the reliability of recycled plastics, making them more suitable for manufacturing applications and thereby increasing their utilisation. Cifrian, Galan [44] assessed recycling rates and examined the impact of various waste treatment methods on recycling outcomes, providing insights into how different strategies affect the overall effectiveness of recycling programs. Milios, Christensen [29] discussed the barriers to plastic recycling, focusing on increasing the use of recycled plastics by overcoming challenges related to quality, contamination, and market acceptance. Rutkowski [45] investigated Extended Producer Responsibility (EPR) schemes and their impact on recycling practices, including the critical role of waste pickers in the recycling sector, which highlights the importance of inclusive and sustainable recycling systems. Castillo-Díaz, Belmonte-Ureña [37] addressed the management of agricultural packaging through a Circular Design and Recycling Reward System (CDRRS), which rewards plastic by-products, thus promoting recycling and reuse strategies in agricultural sectors. Lastly, Ribesse and Robitaille [46] examined a pilot project implementing a recycling system for plastics that are currently sent to landfills, demonstrating the potential for innovative recycling solutions to divert significant amounts of waste from disposal sites.

As the challenges of plastic waste management intensify, the role of technology and market mechanisms in enhancing recycling efforts has become increasingly pivotal. Technological advancements, such as blockchain, RFID, and other digital tools, have revolutionised recycling processes’ tracking, management, and transparency. These innovations ensure that plastic waste is efficiently sorted, processed, and reintroduced into production cycles, reducing the environmental footprint of plastic products and supporting circular economy goals. Zhang, Liu [47] focused on a plastic credit-driven system designed to improve recycling rates and the quality of recycled plastics, using market self-regulation mechanisms to incentivise sustainable practices. Gong, Wang [48] explored the application of blockchain technology in managing and improving the recycling of marine plastic debris, demonstrating how digital tools can be applied to specific environmental challenges. Steenmans, Taylor [49] discussed the use of blockchain to facilitate recycling and reuse rewards, providing a secure and transparent way to incentivise these activities. Similarly, Ellsworth-Krebs, Rampen [41] focused on incentivising and supporting the reuse of packaging through digital tools, which play a crucial role in reducing waste and promoting sustainable consumption patterns. Sankaran [39] highlighted the efficient and sustainable segregation and recycling of plastic waste, underscoring the importance of integrating advanced technologies like AI and blockchain in waste management practices. Hsu, Domenech [35] discussed the development of secondary plastics markets, which directly relate to recycling and reuse efforts by creating new economic opportunities for recycled materials. Kobayashi, Kuwana [50] examined the use of RFID technology in recycling scenarios to track items, aiding in the effective management and recycling of materials. Tang, Chau [28] looked at the impact of blockchain on recycling and remanufacturing, explicitly addressing the recovery and repurposing of materials, which is essential for closing the loop in production cycles. Bhubalan, Tamothran [51] considered how blockchain can support recycling and reuse by tracking plastics throughout the recycling process, enhancing transparency and accountability. Lastly, Liu, Zhang [34] targeted increasing the recyclability of plastics and improving recycling rates by implementing a plastic credit system, which creates financial incentives for companies to adopt more sustainable practices.

Several authors have emphasised the importance of automation and technological advancements in improving the efficiency of waste management processes. Esmaeilian, Sarkis [32] highlighted the role of smart logistics and transportation systems in enhancing the overall efficiency of waste management. These technologies enable more precise tracking, routing, and handling of waste, reducing costs and the environmental impact. Similarly, Khadke, Gupta [42] discussed the automation of segregation and collection processes for plastic waste. By automating these critical stages, waste management systems can achieve higher efficiency, minimise human error, and ensure a more consistent sorting of materials, which is essential for effective recycling. Chidepatil, Bindra [43] also underscored the significance of proper segregation and sorting of plastics, which are foundational to successful recycling and waste management efforts. Effective automation in these areas ensures that plastics are correctly identified and processed, thereby improving recycling rates and reducing contamination in recycling streams.

Another crucial aspect of waste management is the efficient collection and processing of materials, which several authors discuss. Benmoussa [40] linked the improvement of replenishment flows to the efficient management of materials, particularly in waste collection and transportation. Streamlining these processes ensures that waste is collected and transported in a timely and cost-effective manner, which is vital for maintaining the efficiency of the entire waste management system. Additionally, Ribesse and Robitaille [46] focused on collecting and processing recyclable plastics from healthcare facilities. This highlights the need for specialised collection systems that cater to specific types of waste, ensuring that recyclable materials are properly handled and processed, thereby maximising the recovery rates and minimising waste sent to landfills. These authors emphasised the importance of efficient collection and processing as critical components of a successful waste management strategy.

Some authors focused on evaluating different methods for recovering value from waste, mainly through energy and material recovery processes. Tomic and Schneider [25] evaluated various waste recovery methods, emphasising the importance of energy recovery, such as incineration and material recovery, where recyclable materials are extracted from waste streams. These methods are crucial for reducing the volume of waste sent to landfills and maximising the utility of waste materials. Similarly, Gorecki and Nunez-Cacho [26] considered waste management during the decommissioning phase of infrastructure, where significant amounts of waste are generated. They highlight the challenges of managing this waste, particularly in recovering valuable materials during the demolition of infrastructure. Both perspectives underscore the importance of recovery processes in the broader context of sustainable waste management, ensuring that as much value as possible is extracted from waste materials before they are disposed of.

Another group of authors focused on the strategies and frameworks surrounding the treatment and disposal of waste, including the legislative and environmental impacts of these practices. Giorgi, Lavagna [27] discussed waste management strategies, particularly within the legislative framework that governs treatment and disposal practices. They emphasised the importance of complying with regulations while ensuring that waste is treated and disposed of in an environmentally responsible manner. Luan, Cui [36] provided insights into the proportions of plastic waste that are subjected to different treatment methods, such as incineration, landfilling, or discarding. This research highlights the environmental impacts of each method, particularly regarding waste management efficiency and sustainability. Cifrian, Galan [44] further elaborated on the environmental impacts of various treatment methods, such as incineration and composting, mainly focusing on their effects on the carbon footprint. These authors provided a comprehensive view of the challenges and considerations associated with waste treatment and disposal, emphasising the need for strategies that minimise environmental impact while ensuring compliance with regulatory standards.

Multiple authors have highlighted the importance of improving traceability and transparency in waste management systems to enhance recycling practices and ensure accountability. Steenmans, Taylor [49] highlighted how blockchain technology facilitates the monitoring and tracking of waste, essential for creating transparent waste management systems. Milios, Christensen [29] discussed the need for better traceability and transparency throughout the value chain to improve recycling outcomes, ensuring that waste materials are appropriately managed and recycled. Ellsworth-Krebs, Rampen [41] introduced the concept of Digital Passports, which are used to audit, track, and report on the reuse of packaging, thus improving accountability within circular economy practices. Similarly, Tomic and Schneider [25] used a lifecycle assessment (LCA) framework to track waste, material, and energy flows, providing a comprehensive assessment of the impact of waste management practices. Castillo-Díaz, Belmonte-Ureña [37] also showed that traceability systems within waste management should be established to monitor and enforce proper practices, aligning with the goal of transparent and efficient waste management. Incentives and motivations for implementing traceability systems in waste management are driven by a combination of regulatory, economic, environmental, and reputational factors. Organisations and governments are increasingly adopting traceability measures to ensure compliance with environmental regulations, which often mandate transparency in the management and recycling of waste materials. Regulatory frameworks not only enforce proper waste handling but also provide legal backing to ensure that products and materials are traced throughout their lifecycle, promoting sustainability and accountability. Additionally, market competitiveness is another significant driver, as companies that adopt traceability systems can demonstrate their commitment to sustainability, giving them an edge in industries where environmental responsibility is becoming a critical selling point. Consumers, now more aware of environmental issues, are demanding greater transparency in the products they purchase, particularly regarding their origins, production processes, and disposal methods. Moreover, implementing traceability systems offers economic benefits by improving the efficiency of recycling practices, reducing waste management costs, and enhancing resource recovery, all of which contribute to a more circular economy. For example, blockchain technology and Digital Passports, as discussed in previous studies, not only facilitate compliance but also allow businesses to differentiate themselves in markets increasingly focused on sustainability. The environmental benefits, particularly the reduction of pollution and resource wastage, further incentivize stakeholders to adopt traceability systems, as they contribute to a lower carbon footprint and a more sustainable operational model. Finally, reputational benefits are also a key motivation. Companies that demonstrate strong environmental stewardship through traceability can enhance their public image, foster consumer trust, and attract investments, all of which are crucial in today’s environmentally conscious marketplace. Thus, the convergence of these incentives drives the growing adoption of traceability systems in waste management.

3.2. Governance

Another group of authors focused on the importance of monitoring and enforcing waste management practices, mainly through advanced technologies like blockchain and the development of comprehensive policies. Hsu, Domenech [35] discussed the role of policies, standards, and knowledge sharing in the circular economy, which includes monitoring and enforcing sustainable practices. Giorgi, Lavagna [27] highlighted the need for the better coordination and enforcement of circular economy practices, ensuring that waste management systems operate effectively and sustainably. Bhubalan, Tamothran [51] emphasised how blockchain technology can provide transparent tracking of waste, aiding in enforcing waste management regulations and standards. Additionally, Rutkowski [45] focused on improving the traceability and efficiency of waste management systems, which inherently involves monitoring and enforcing compliance with waste management protocols. In the context of marine pollution, several studies have emphasised the importance of monitoring and tracking plastic pollution to support enforcement efforts. Reisser, Shaw [52] focused on monitoring and assessing marine plastic concentrations and pathways, critical for managing and mitigating plastic pollution. Maes and Blanke [53] used ocean modelling to track plastic litter and determine its origins, providing data that can support enforcing marine pollution regulations. Courtene-Jones, Maddalene [38] employed comprehensive sampling and tracking methods to monitor plastic pollution, assessing the effectiveness of local and international regulations. These monitoring efforts are crucial for understanding plastic pollution’s scope and enforcing measures to reduce its impact on marine environments. Andrades, Martins [31] further supported this approach by evaluating and tracking debris sources and pathways, providing data that could enhance monitoring and enforcement efforts related to marine pollution. Cheng, Hao [54] used blockchain technology to monitor and enforce recycling practices, ensuring compliance through a tamper-proof record of recycling activities. Finally, Di, Reck [55] analysed material flows from production to end of life, reporting on recycling rates and providing insights that can be used to monitor and enforce waste management regulations and sustainability goals.

Castillo-Díaz, Belmonte-Ureña [37] recommended using subsidies and fiscal measures to encourage environmentally friendly practices, which involve engaging producers and the public. This approach highlights the importance of economic incentives in promoting sustainable practices and the need for active participation from various stakeholders to drive environmental change. Milios, Christensen [29] also discussed complementary measures such as public procurement and bans on incineration, which imply a role in educating and engaging the public and policymakers. These strategies are essential for creating a supportive recycling and waste management environment, ensuring that stakeholders are informed and motivated to participate in sustainability efforts.

Johnson, Chambers [56] emphasised the need for transdisciplinary efforts involving chemistry and law, underscoring the importance of educating stakeholders and engaging them in efforts to combat plastic pollution. This approach highlights the necessity of integrating knowledge from various disciplines to develop practical solutions for managing plastic waste. Engaging stakeholders, including the public, policymakers, and industry players, is crucial for creating a comprehensive approach to tackling plastic pollution. This engagement ensures that all parties are informed, aligned, and actively involved in efforts to reduce plastic waste and its environmental impact.

3.3. Digital Enabler

Jin, Qin [57] highlighted the integration of sensors, wireless communication, and mobile applications, which fits into the broader theme of technology integration in waste management. Wang, Zhang [58] further explored this by focusing on applying Cyber-Physical Systems (CPSs) and digital twin models to enhance traceability, productivity, and energy efficiency in manufacturing, showcasing the role of advanced technologies in improving operational efficiency. Esmaeilian, Sarkis [32] discussed the use of the IoT and blockchain to track, optimise operations, and enhance transparency, demonstrating how digital tools are being utilised for better waste management. Similarly, Colicchia, Creazza [33] examined Supply Chain 4.0 technologies, including digital tools and systems, to boost sustainability and traceability. These studies collectively emphasise the growing importance of integrating advanced technologies into waste management practices to enhance efficiency, transparency, and the overall system performance.

Steenmans, Taylor [49] explored the use of blockchain for smart contracts and other digital solutions, aligning with the theme of digital traceability in waste management. Ellsworth-Krebs, Rampen [41] discussed using Digital Passports and reporting systems to support traceability and address data management issues, enhancing trust in the system. Gorecki and Nunez-Cacho [26] implied the potential use of technologies for improving waste management and material tracking within the context of the circular economy, while Giorgi, Lavagna [27] mentioned the need for digital tools and platforms to support circular economy practices. Khadke, Gupta [42] and Chidepatil, Bindra [43] both focused on blockchain technology, with Khadke highlighting its use in tracking and managing plastic waste and Chidepatil, Bindra [43] emphasising blockchain- and AI-powered algorithms for better plastic segregation and recycling. These authors collectively illustrated the critical role of blockchain and digital traceability systems in modernising waste management, ensuring transparency, and supporting circular economy practices.

3.4. Physical Enablers

Luan, Cui [36] focused on material flow analysis (MFA), a methodology that tracks plastics’ physical movement and management over time. This approach does not involve digital tracking systems but instead emphasises understanding the physical flow of materials and projecting future trends in plastic use and waste. The emphasis here is on the comprehensive tracking of plastics throughout their lifecycle, providing insights into managing plastic resources and waste.

Teulon, Palleau [59] introduced a novel technological approach, Nanogel Marking, which integrates advanced materials and techniques to improve traceability and authentication. This method represents a significant innovation in enhancing traceability using cutting-edge materials science. It offers new possibilities for ensuring the authenticity and tracking of materials through their lifecycle. This approach highlights the role of advanced technology in improving traceability beyond traditional or digital systems, focusing on material-specific innovations.

Several authors have discussed integrating physical and digital traceability systems in waste management and circular economy practices. For example, Tomic and Schneider [25] combined lifecycle assessment (LCA) with economic calculations, which involve physical aspects of waste management practices and digital aspects such as data analysis and modelling. Similarly, Zhang, Liu [47] focused on a system that combines the physical evaluation of plastic recyclability with digital elements like blockchain-enabled smart contracts and plastic credit trading. Hsu, Domenech [35] addressed both physical and digital traceability aspects by discussing data–information–knowledge interactions, policy impacts, and certification practices, illustrating how these elements interact in a complex waste management system. Gorecki and Nunez-Cacho [26] and Giorgi, Lavagna [27] highlighted the traceability of construction materials within a circular economy context, suggesting that physical material handling and digital data management play crucial roles. Additionally, Kobayashi, Kuwana [50] focused on improving RFID technology for tracking items throughout their lifecycle, blending physical RFID tags with digital solutions for data management and privacy protection. Castillo-Díaz, Belmonte-Ureña [37] emphasised biodegradable plastics and the physical management of packaging waste coupled with RFID and blockchain technologies to monitor waste management practices, thus combining physical and digital traceability systems. Similarly, Benmoussa [40] discussed replenishment process improvements involving physical aspects like inventory management, supported by digital data collection and simulation analysis for process optimisation. Andrades, Martins [31] involved tracking and evaluating the source of debris (physical traceability) while using digital data analysis to understand environmental impacts.

Several studies have highlighted the role of advanced technologies in enhancing traceability within waste management systems. Sankaran [39] discussed using multi-sensor-driven AI and blockchain tools for waste management, emphasising the integration of cutting-edge technologies for better traceability and management. Chaudhuri, Subramanian [24] highlighted the adoption of digital technologies such as 3D printing and blockchain, which are instrumental in improving the traceability and sustainability of waste management practices. Chen, Yu [30] described a rewritable 2D barcode system that enhances traceability and efficiency through data encryption and a rewritable layer, showcasing a technological solution for better resource utilisation. In the marine and environmental context, Courtene-Jones, Maddalene [38] involved the physical sampling of environments to assess plastic pollution while also employing digital modelling and particle tracking to understand and predict the sources and distribution of plastic pollution. Johnson, Chambers [56] mentioned sequence-defined polymers, which can provide detailed material tracking, suggesting that these advancements could be integrated with governance frameworks to improve traceability and management. These examples illustrate how digital tools, AI, blockchain, RFID, and other advanced technologies are being leveraged to create more robust and effective traceability systems across different sectors and contexts.

4. Overall Analysis and Discussion of Results

The synthesis of findings from the SLR, alongside insights into industry trends, highlights the necessity for a new traceability system, setting the stage for exploring our conceptual framework in this section.

It becomes evident from the systematic literature review (SLR) that quality is a missing yet essential component when discussing traceability and waste management. Quality plays a critical role in determining the future use of materials, particularly in the context of transitioning waste into a resource [14]. While virgin-grade materials are rigorously assessed and qualified by both material producers and converters, ensuring they meet strict performance standards, recycled materials often lack the same level of qualification. This limited exposure to quality assessment for recycled materials presents a significant challenge, as it hinders their broader acceptance and integration into manufacturing processes. Without a standardised approach to qualifying the quality of recycled materials, their potential as a resource in circular economy models remains underutilised. Quality assurance, therefore, is vital for ensuring that recycled materials meet the necessary criteria for reuse in high-performance applications, thereby enhancing their value and functionality within the supply chain.

The analysis reveals critical insights into plastic waste management’s digital and physical traceability methods. Digital traceability methods, such as barcodes, RFID, and blockchain, offer significant advantages in data capture, storage, and real-time tracking. These methods are increasingly being integrated into waste management systems to improve the transparency and efficiency of tracking materials from collection to recycling and disposal. The research highlights the potential of digital traceability to enhance data accuracy, streamline operations, and facilitate compliance with regulatory requirements.

In contrast, physical traceability methods, which involve directly marking or tagging physical objects with identifiers, are also crucial but present unique challenges. These methods ensure that materials can be physically traced throughout their lifecycle, which is particularly important for verifying the composition and source of recycled materials. However, physical traceability methods can be more resource-intensive and may sometimes provide a different level of detail than digital methods. The research points out that, while physical traceability is essential for certain aspects of waste management, particularly in verifying the authenticity of recycled content, digital approaches are often more flexible and complex.

The findings suggest that digital and physical traceability methods may be necessary to achieve comprehensive traceability in waste management systems, particularly for plastic waste. Integrating these methods can help address the challenges posed by the varied nature of waste materials and the need for accurate tracking across complex supply chains. The research underscores the importance of developing integrated systems that leverage digital and physical traceability strengths to enhance the overall system performance and support the goals of a circular economy.

While GS1 offers a robust framework for supply chain traceability, there are areas where it may need improvements, particularly in the context of integrated waste management and circular economy initiatives. One area for improvement is its focus on digital identification and data sharing, with less emphasis on physical traceability methods like material marking technologies. Integrating guidance on physical traceability, such as RFID tags, QR codes, or chemical markers, could improve the accuracy of material tracking. Additionally, the granularity of the data shared under GS1 standards might be insufficient, overlooking detailed information on environmental impact, specific recycling methods, or the precise composition of recycled materials. Enhancing data granularity could yield more profound insights into product and process sustainability. The biggest challenge in plastic recycling is the fact that the composition of materials for processing and sorting is unknown. Rumetshofer and Fischer [60] provided evidence that the plastics recycling supply chain would improve the sorting steps, reduce contamination levels, and increase the value of the recycled material by adopting a traceability system.

Moreover, while GS1 standards are designed for standardised data formats, they may need to fully align with emerging technologies like blockchain, AI, and the IoT. More explicit guidelines for integrating these technologies could enhance real-time tracking and automated decision-making. The GS1 framework is global, but it might only partially accommodate regional or local policies, necessitating more localised guidance or flexibility to meet specific regulatory requirements.

Consumer engagement is another area where GS1 could improve, as the current focus is more on supply chain visibility than on educating consumers about traceability information and its sustainability implications. This education could foster more excellent public support for circular economy initiatives. The resource-intensive nature of GS1 implementation could also pose challenges for small and medium enterprises (SMEs), so more accessible and cost-effective solutions would be beneficial in encouraging broader adoption among smaller businesses.

Regarding sustainability, GS1 could integrate comprehensive metrics into its framework, such as carbon footprint, resource efficiency, and waste reduction, to provide a more holistic view of the environmental impact. Lastly, while the GS1 framework is robust, it may need more flexibility to adapt quickly to changing market conditions or new business models. It is vital for maintaining relevance and effectiveness in the face of evolving circular economy practices and technological advancements.

It is accurate to note that emissions from blockchain systems, the IoT with no-battery systems, and embedded traceability systems are not explicitly addressed in the GS1 and Australian frameworks. These frameworks primarily concentrate on practical traceability implementations and standardising data elements to ensure supply chain consistency and transparency. However, this oversight presents an opportunity for a future research paper to explore the interaction of these emerging technologies with existing traceability systems, identifying potential gaps and opportunities for enhancement.

While blockchain is acknowledged for its transparency and trust benefits within traceability systems, its significant energy consumption and emissions are often overlooked. These environmental impacts are critical, especially in sectors aiming to reduce their carbon footprints. Similarly, IoT systems that operate without batteries could offer sustainability advantages by eliminating the waste associated with battery use and enabling the continuous monitoring of products without the environmental burden associated with battery disposal. Nevertheless, their integration into existing traceability frameworks could require substantial adjustments to accommodate continuous, real-time data streams that current systems may need to handle more effectively.

Moreover, embedded traceability systems present innovative approaches by integrating traceability directly into products or packaging. This can enhance consumer transparency and support efficient recall processes and product verification. However, these systems also pose challenges in standardisation across industries and compatibility with broader traceability standards, highlighting a need for frameworks to evolve and address these advanced technologies.

In recent years, several companies have begun implementing traceability systems in the plastics industry, with blockchain technology playing a dominant role. Companies like Dell, BASF, and Covestro, among others, have launched various traceability projects [61,62,63,64,65,66,67,68,69]. These projects generally aim to improve transparency, trust, and sustainability claims within their supply chains. While many of these initiatives are still in the pilot or early implementation stages, they showcase a growing trend towards leveraging technology to address the complex issues of plastic waste and recycling. Other significant projects include Circularise Plastics [70], a Dutch initiative that brings together various stakeholders like Porsche and Borealis to create a circular economy model with blockchain traceability. Despite the promising projects, a major limitation is that most of these efforts do not analyse critical aspects like the financial costs or environmental impacts of implementing such advanced technologies. While blockchain is a popular solution for these companies, its high energy consumption and associated carbon footprint have not been sufficiently explored. Furthermore, the focus on blockchain overlooks the potential benefits of integrating digital and physical traceability systems more effectively. While companies like Tetra Pak are exploring smart packaging using QR codes to connect with customers [63], and Dotz Nano is developing traceable markers for high-temperature applications, there remains a significant gap in addressing the full integration of digital and physical solutions for plastic waste tracking [71]. Projects like Circularise aim to address this gap by combining anti-counterfeiting technologies such as QR codes, labels, and chemical tracers with blockchain to enhance traceability and prevent counterfeiting. Similarly, initiatives like RecoTrace [72], which is led by PolyRec, use a digital tracking system for plastic waste accounting, providing transparency for European plastic recyclers and converters. However, these projects still lack a comprehensive physical tracking solution that can handle the diverse material types in the plastic waste stream and improve the overall quality of recycled materials. One notable approach is the use of tagging technologies, such as Near-Field Communication (NFC) tags or smart tags, which can be embedded into packaging to store material composition and provenance information. For instance, Polysecure [73] is developing a fluorescent ink system that can be integrated into products for easy identification using particle fingerprint technology. This type of innovation could significantly improve the sorting and recycling process, but there are still technical and cost barriers that need to be addressed before widespread adoption is possible. Another interesting development is the HolyGrail 2.0 project [74], which focuses on digital watermarking for packaging. This initiative aims to improve waste sorting efficiency by embedding invisible digital watermarks in packaging materials that can be scanned to identify the material type and improve recycling outcomes. While this project holds promise, like others, it has yet to fully address the broader challenges of cost and scalability.

The study faces two significant limitations that should be discussed in more depth, particularly from a future research perspective. First, the integration of digital and physical traceability systems presents practical challenges that have not been fully explored in the paper. While the research highlights the importance of combining digital technologies, such as blockchain and RFID, with physical methods like QR codes or chemical markers, it does not adequately address the technical and operational difficulties involved. Future research should focus on the issue of interoperability, investigating how these systems can effectively communicate and function across different platforms using a case study methodology. Additionally, scalability remains a concern, particularly for smaller companies that may lack the financial or technological resources to implement such advanced systems. Further studies could explore scalable solutions and provide more accessible frameworks for smaller organisations, making these systems more inclusive. A second limitation is the absence of real-world data or case studies in the current analysis. The study relies heavily on theoretical frameworks and insights from the literature but lacks empirical evidence on the practical outcomes of implementing traceability systems in plastic recycling. Without data on how these systems perform in actual industry settings, it is difficult to assess their true impact on improving recycling rates, reducing contamination, or lowering costs. Future research should prioritise gathering data from organisations that have implemented blockchain or other digital traceability systems to better understand their effectiveness and challenges in practice. Furthermore, because the findings are based on theoretical discussions, their generalisation across different industries and regions remains uncertain. Future research could focus on evaluating these systems in a variety of contexts to provide more nuanced insights and ensure broader applicability. By addressing these limitations, future studies can build a more comprehensive understanding of the real-world challenges and opportunities in developing effective traceability systems for the plastic recycling industry.

In order to introduce how the traceability system could operate, an example using PET bottles will be discussed. PET is one of the most widely used types of plastic bottle packaging and plays a central role in beverage markets due to their durability, lightweight nature, and suitability for storing products like water and carbonated drinks. In 2022, approximately 5 million tonnes of PET products entered the European market, with beverage bottles making up around 62%, emphasising their dominance in plastic usage. Similarly, PET is a major component of single-use packaging in North America, contributing significantly to plastic waste streams [75,76]. However, the recycling pathways for PET bottles present substantial challenges, making them an ideal case for examining the role of traceability in sustainable packaging [77]. While PET bottles are recyclable, achieving high-quality recycling is hindered by contamination, limited collection infrastructure, and processing variability, especially across regions [78]. The lifecycle of PET bottles encompasses several stages where traceability could improve transparency and sustainability. During the production and distribution phase, traceability systems can document the PET’s origin, whether it is virgin or recycled content, and log details about the manufacturing process. Technologies like blockchain or digital markers on packaging could validate claims about recycled content percentages, which is essential for companies like Coca-Cola that aim to demonstrate sustainability through targets such as 50% recycled content in all packaging by 2030 [79]. By tracking recycled material from the source, companies can ensure that their production aligns with environmental commitments, enhancing consumer trust and supporting regulatory compliance. In post-consumer waste management, traceability is critical in improving sorting accuracy and preventing contamination. Using identifiable markers like QR codes or embedded digital tags, waste management systems can efficiently differentiate between recyclable and non-recyclable PET, helping to streamline sorting processes and reduce contamination. This differentiation is essential, as contamination during collection often reduces the quality of recycled PET, creating barriers to producing high-grade, food-safe rPET. For Coca-Cola and other large beverage companies, accurate sorting helps meet their recycling goals. It maximises the value of PET bottles collected, which is crucial given the limited availability of quality recycled PET feedstock [80,81,82,83,84,85]. Finally, in the recycling and reuse stage, traceability can ensure that the recycled PET meets the quality standards necessary for reuse, particularly in food contact applications. Traceability systems could monitor each batch of recycled PET, verifying that it meets safety and quality requirements, thus preventing contamination and supporting closed-loop recycling. This capability is especially relevant, as Coca-Cola and others face pressure to provide high-quality, food-grade rPET for new bottles. By tracking recycled content through every processing phase, companies can secure a consistent supply of quality rPET, align their operations with environmental claims, and address supply constraints [80,81,82,83,84,85]. The extensive use of PET bottles and the challenges of managing their recycling lifecycle underscores their relevance as a case study for traceability. Through traceability systems, companies can document the entire lifecycle of PET bottles, from production to final reuse, creating accountability and transparency while promoting sustainable waste management within a circular economy framework. These systems help validate recycled content claims, reduce contamination, and facilitate efficient sorting and recycling, ultimately contributing to both environmental goals and consumer trust [80,81,82,83,84,85].

As shown in Figure 4, an enhanced traceability framework for PET bottles can be achieved by combining QR codes, RFID, and blockchain technology across the supply chain, from primary production to recycling and conversion. Each of these technologies contributes unique strengths that create a robust system for tracking, verifying, and managing PET bottles throughout their lifecycle. In the primary production stage, QR codes and blockchain can be used to document PET bottle sourcing and manufacturing details, providing an initial layer of traceability. QR codes on each bottle can store information about the recycled content, batch number, and production date. This information becomes accessible to stakeholders across the supply chain, allowing for transparency from the start. Blockchain technology can securely record these details in a decentralised ledger, ensuring the data remain tamper-proof. This combination of QR codes and blockchain helps companies like Coca-Cola validate claims about recycled content percentages, while consumers and regulators can view and verify this information. As the bottle moves through distribution and consumer use, QR codes remain a low-cost and easily accessible method for consumers to engage with product sustainability information. By scanning the QR code, consumers can access information on recycling practices, contributing to responsible disposal. Blockchain securely stores each bottle’s journey at this stage, creating a verified record of its path from production to the consumer. This setup fosters transparency and encourages environmentally conscious consumer behaviour by reinforcing traceability at the user level. In the post-consumer waste management stage, RFID technology facilitates sorting and streamlining recycling. RFID tags on PET bottles provide a more durable form of traceability than QR codes, particularly as bottles undergo rough handling during collection and sorting. Waste management facilities with RFID readers can quickly identify, sort, and track PET bottles based on their material composition and origin, even in bulk processing environments. This level of traceability improves the sorting efficiency, minimises contamination, and helps ensure that PET bottles are correctly sorted for recycling rather than disposal. Blockchain can store this sorting data, enabling an unbroken chain of information from manufacturing to waste management and providing companies with insights into the efficiency of post-consumer collection efforts. Combining RFID and blockchain continues to provide traceability and quality assurance during the recycling and conversion stage. As PET bottles are processed into recycled PET (rPET), the blockchain records the data from the conversion process, such as the quality and contamination levels of the recycled material. RFID tags on individual bottles provide traceable data on each batch of rPET, ensuring that the final recycled product meets food-grade standards and is safe for reuse in packaging. This traceability is particularly valuable for companies striving to meet high recycled content targets, as it allows them to validate the quality and quantity of rPET in their products. Despite the strengths of this integrated approach, several challenges exist. The high volume of PET bottles produced annually creates logistical challenges for implementing these technologies on a large scale. The cost and environmental impacts of RFID tags and blockchain infrastructure may need further consideration and research, especially for smaller facilities or regions with limited resources.

Contamination in PET bottle recycling can be minimised by employing an integrated traceability system that enhances the sorting accuracy, monitors the material purity, and tracks contamination sources across the supply chain. By tagging each PET bottle with RFID or QR codes, waste management facilities can efficiently scan and sort bottles according to their composition. RFID tags, in particular, enable automated bulk sorting, reducing the chances of human error and ensuring that only compatible PET materials are processed together. This targeted sorting reduces contamination from non-PET materials, which otherwise could degrade the quality of recycled PET. In addition to digital tags, chemical markers or smart labels embedded in PET bottles help distinguish food-grade plastics from non-food-grade types, facilitating precise separation. These markers can be detected during sorting to ensure that only high-purity, food-grade PET is processed for food contact applications. At the same time, non-food-grade PET is directed toward other recycling streams. Blockchain technology further supports contamination control by recording comprehensive data on each bottle’s lifecycle, including any contamination detected at various stages. If a batch shows high contamination, the blockchain ledger allows easy tracing back to the contamination source, such as a specific facility or collection method, enabling targeted interventions to improve the system. Automated cleaning systems and quality control mechanisms also contribute to contamination prevention. Advanced recycling facilities equipped with robotic or automated cleaning systems can remove contaminants from PET bottles before processing, while automated quality control systems—supported by real-time data from RFID and blockchain—alert operators to contamination risks. This stops contaminated batches from entering production, preserving the quality of the recycled PET output.

Additionally, consumer education through QR codes can play a significant role in reducing contamination at the source. By embedding recycling instructions in QR codes, such as guidelines for rinsing bottles before disposal, consumers are encouraged to reduce residual contaminants in PET bottles. This proactive engagement helps maintain a cleaner recycling stream, reducing the risk of contamination from the start. The traceability system significantly reduces the contamination risk through this combination of RFID, blockchain, chemical markers, and consumer engagement via QR codes. Accurate sorting, continuous tracking, and automated quality checks ensure that only clean, compatible materials are processed together, enhancing recycled PET production’s overall quality and efficiency. This multi-layered approach to traceability strengthens the recycling process and supports sustainable PET management.

Nonetheless, the potential benefits of an enhanced traceability framework are significant. Combining QR codes, RFID, and blockchain improves recycling rates, facilitates the production of higher-quality recycled materials, and enhances transparency throughout the PET supply chain. These technologies ensure that each stage of the PET bottle’s life is accounted for, allowing companies to meet regulatory and sustainability standards more effectively. This comprehensive approach to traceability supports a circular economy by maximising the efficient reuse of PET, reducing plastic waste, and fostering consumer trust in sustainable packaging claims.

The specific types of data stored on-chain and how each contributes to more effective and efficient recycling processes. Blockchain technology’s core advantage lies in its ability to create a permanent, tamper-proof record of data, which ensures that information critical to the recycling lifecycle is accurate, accessible, and transparent to all stakeholders. Firstly, recycled content percentages are recorded on-chain to verify the amount of recycled material in each batch or product. By storing this data, manufacturers can transparently demonstrate compliance with regulatory requirements and sustainability commitments. This information is valuable for quality control and for confirming that products labelled as containing recycled material meet specified recycled content standards. Secondly, the source of origin information provides a traceable record of where the plastic material originated, whether from post-consumer waste, industrial scrap, or other sources. By tracing the origin, stakeholders can ensure compliance with quality standards, identify the geographic and operational sources of plastic, and address any inconsistencies or contamination issues. Origin data also support claims of sustainable sourcing and circularity, convincing consumers that the material’s journey is responsibly documented. Thirdly, contamination levels are tracked on-chain to ensure that only clean, high-quality material enters the recycling process. Data on contamination allow for improved sorting at recycling facilities, as it can signal when additional cleaning steps or processing adjustments are necessary. Storing contamination data also helps recyclers and manufacturers identify patterns and sources of contaminants, allowing them to take corrective actions upstream to improve the quality of future recycling inputs. Additionally, blockchain can store processing and handling data at each stage of the recycling chain. This includes information on sorting, cleaning, processing methods, and timestamps of when these actions took place. By capturing these details, blockchain enhances process accountability and allows for continuous quality monitoring. For example, if recycled materials fall short of the quality standards, blockchain data can help pinpoint where the chain issues occurred, facilitating process improvements and reducing waste from substandard materials. Finally, certifications and compliance data can also be stored on-chain, offering an accessible record of quality and regulatory compliance for recycled plastics. Certifications for food-grade or high-quality recycled plastics can be embedded in the blockchain, allowing downstream users to verify that the recycled material meets the necessary standards before it is incorporated into new products. Recording these types of data on a tamper-proof blockchain makes recycling processes more transparent and efficient. Blockchain’s role in securing this information enables the accurate tracking of materials, facilitates high-quality recycling by ensuring standards are met, and supports the circularity of plastics by documenting each stage of the recycling lifecycle.

5. Conclusions

The literature highlights a critical need for consistency in defining traceability concepts, particularly related to blockchain technology within traceability systems. A vital strength of the existing research lies in establishing connections between blockchain technology and traceability, setting a foundation for future exploration. Engaging all stakeholders across the supply chain enables a more thorough understanding of traceability challenges while analysing industry trends, revealing a significant shift towards digital solutions. However, a scarcity of publications fully addressing integrating digital and physical traceability systems within industrial settings validates the need for a holistic framework that combines both.

While the GS1 framework offers robust guidelines for global supply chain traceability, its primary focus on digital identification and data sharing overlooks essential aspects of integrated waste management and circular economy practices. Notably, GS1 needs to fully account for physical traceability methods like RFID tags, QR codes, or chemical markers, which are essential for tracking materials throughout their lifecycle. This gap in data granularity limits the framework’s ability to provide an in-depth understanding of environmental impacts, specific recycling processes, or the exact composition of recycled materials. Such details are crucial for assessing product sustainability more accurately.

Moreover, while the GS1 framework has the potential for integration with advanced technologies like blockchain, AI, and the IoT, these connections are underdeveloped. This lack of explicit guidance limits the framework’s ability to leverage real-time tracking and automation to its fullest extent, presenting an opportunity to enhance the use of these technologies within traceability systems. Additionally, since GS1 operates globally, it may sometimes align with regional or local regulations, which could necessitate localised guidance to meet diverse regulatory requirements.

Consumer engagement presents another area where GS1 could expand its focus. Although the framework prioritises supply chain visibility, it must educate consumers on traceability information’s sustainability implications. By enhancing consumer awareness, GS1 could foster greater public support for circular economy initiatives, which are essential for the long-term success of sustainable practices. Implementing GS1 standards can also be resource-intensive, posing challenges for small- and medium-sized enterprises (SMEs) with limited capacity to adopt complex traceability systems. Developing more accessible, cost-effective solutions would facilitate broader adoption among smaller industry players.

To support sustainability, GS1 could integrate metrics like carbon footprint, resource efficiency, and waste reduction, offering a more comprehensive view of environmental impacts and informing stakeholders’ decision-making. However, the framework’s rigidity might limit its adaptability to evolving market conditions or new business models, such as those arising from circular economy practices and technological advancements. Ensuring flexibility and responsiveness is vital for maintaining the GS1 framework’s relevance and effectiveness in a rapidly changing landscape.

The broader literature on waste prevention and circular economy principles also addresses areas that could complement the GS1 framework’s limitations, emphasising product design, sustainable practices, and circular economy models. Nevertheless, gaps still need to be discovered, particularly regarding how waste management strategies could be systematically integrated with traceability frameworks like GS1 to enhance environmental sustainability and supply chain efficiency. Further research could delve into these intersections, outlining strategies for aligning traceability with waste management and circular economy principles.

Our research suggests that combining digital and physical traceability approaches offers significant opportunities for improving the recycling stream. Nonetheless, a lack of interoperability among existing systems remains a substantial challenge, underscoring the need for standardised data identification, verification, and physical tracking approaches. Policymakers should prioritise these standardised methods to foster efficient traceability system implementation across various sectors.

Regarding policy implications, effective traceability systems are vital in global plastic management strategies. By providing transparent, verifiable data on plastic materials’ lifecycles, traceability systems can enable data-driven policymaking that addresses plastic waste at its source, aligning environmental objectives with regulatory compliance. These systems offer policymakers critical insights into material flows, identifying where waste reduction efforts could be concentrated and promoting circular practices such as designing recyclable plastics and using recycled materials. These insights directly inform national and international plastic management strategies, ensuring policies are based on reliable data and effectively address plastic waste complexities.

Regulatory frameworks can also benefit from traceability systems, as data enable monitoring compliance with plastic waste regulations. Many countries require a minimum recycled content in products, but verifying compliance can be challenging. Traceability systems can track recycled content reliably, ensuring claims meet regulatory standards. By documenting contamination levels and processing details, traceability also aids in enforcing quality standards for recycled materials, supporting the production of high-quality, food-grade plastics that meet safety standards. In this way, traceability systems directly support policy measures that promote transparency and accountability in the plastic supply chain.

On an international level, traceability systems foster collaboration, primarily as countries work towards harmonised recycling standards through initiatives like the Basel Convention. Standardised traceability practices supported by interoperable technologies, such as blockchain, facilitate a consistent approach to tracking plastic waste, aiding cross-border cooperation on sustainability goals. By establishing a unified traceability system, nations can better tackle cross-border issues like waste mismanagement and illegal plastic trade.

We recommend practical pathways for policymakers and industry stakeholders to support the effective implementation of traceability systems. First, pilot programs could test traceability technologies in specific regions or industries, providing insights into effectiveness and scalability. Second, investing in interoperable digital technologies, such as blockchain and RFID, can ensure seamless data sharing across platforms and organisations. Lastly, policymakers could incentivise traceability adoption through subsidies or tax breaks, encouraging companies to participate and accelerating circularity in plastic management.

In conclusion, a well-integrated traceability system can track plastic materials responsibly, enhance recycling, and ensure sustainability across the supply chain. This approach benefits the environment, supports regulatory compliance, and provides a foundation for a global, sustainable approach to plastic production and consumption. Through collaborative efforts and the integration of both digital and physical tracing mechanisms, the foundation for a more sustainable future in plastic management can be established, enabling more transparent, efficient, and environmentally responsible production and recycling practices.