Safe-and-Sustainable-by-Design Framework: (Re-)Designing the Advanced Materials Lifecycle

Abstract

In the last few years, the materials research community has shown increased interest in Advanced Materials (AdMas) that are specifically designed to substitute the traditionally used materials, not only with a view to their sustainability, sourcing criticality, or scarcity, but also to maintaining or even enhancing their functionality and performance. The use of AdMas is particularly researched in sectors where the environmental impact of the traditional materials is substantial, in terms of waste production or resource consumption. Due to their novelty and potentially unpredictable impacts, and to add further value to their application, there is an increasing interest in the safety and sustainability of AdMas. In this context, a new 5-step Safe-and-Sustainable-by-Design (SSbD) framework was developed by the European Union, to support the (re-)design and development of novel materials. A guideline is presented for enforcing the (re-)design phase of the framework with paradigms to guide stakeholders and practically add value to the materials’ industry. The present manuscript analyzes the advances and challenges of the SSbD framework, showcasing its applicability and limitations and the added value compared to traditionally used assessment methodologies, to provide a comprehensive evaluation of the methodology and add value to the materials’ industry concerning safety and sustainability.

1. Introduction

In the last few years, advanced materials (AdMas) have been within the basic interests of the research community in the European Union (EU) and worldwide. They are specially engineered to display superior properties and performance compared to conventional materials, e.g., enhanced strength, durability, and corrosion resistance [1], and their numerous, promising potential applications make them highly desirable. They can be composed of different structures, such as polymers [2], metals and multidoped alloys [3], electroceramics, optoceramics [4], and composites. They are used for various applications, namely aerospace [5,6], wind turbines [7], and marine equipment [8], to name a few. These materials are often manipulated at the molecular or nanoscale to achieve the desired characteristics [9]. In fields where replacing existing materials is essential for sustainability, such as renewable energy sources (solar and wind), there is an anticipated surge in demand for advanced materials in applications such as photovoltaic cells, batteries, and fuel cells. The research community is steering its efforts towards AdMas development through various fields. For instance, the growing demand for electric vehicles, which aligns with the EU’s goals for zero emissions [10], is driving the industry to rechargeable lithium-ion batteries since they are environmentally friendly and have a longer lifespan than traditional lead-acid batteries [11]. In addition, smart materials that can respond to environmental changes such as temperature, pressure, or light have contributed to the global AdMas market growth over the past few decades [11]. Notably, the overall market size of AdMas was estimated at 65.2 billion USD in 2023 and is expected to reach 112.7 billion USD by 2032 with a Compound Annual Growth Rate (CAGR) of 6.27%, according to forecasts [12].

Alongside the evolution of AdMa technology, the EU is committed through several regulations (Green Deal [13], Strategy for Financing the Transition to a Sustainable Economy [14], Chemicals Strategy for Sustainability [15], Circular Economy [16], Zero Pollution Action Plan [10], IAMi-Innovative Advanced Materials Initiative, etc.) to take action regarding environmental conservation and support sustainability and circularity throughout products’ lifecycles. Advanced (nano)materials are essential in enabling emerging nano and biotechnologies, which are recognized as key enabling technologies (KETs). These KETs play a crucial role in the transition towards sustainable innovation across various industrial sectors, including construction, energy, electronics, etc. [17]. For instance, Pb-free piezoelectric materials have been of interest since 1999 because of the aforementioned regulations [18]. Today, piezoelectric polymers show great promise for developing batteries, sensors, nanogenerators, and many other applications [19].

Societal and industrial shifts, driven by climate change and regulation enforcement, drive the operations of tomorrow optimized across multidimensional business objectives —including sustainability goals. As sustainable design has evolved, some subdisciplines have matured enough to represent independent research areas, including sustainability-oriented design for X (DfX) methods. In 2022 the EU’s Joint Research Centre (JRC) introduced a new framework, the ‘Safe-and-Sustainable-by-Design’ (SSbD) [20], as an evolution of traditionally used techniques. The transition from Safe by Design (Sbd) to SSbD aims to integrate sustainability and socioeconomic aspects along with safety, and at the same time, explores the link between them [21]. It involves a two-step process: (1) a safety and sustainability assessment phase, which produces the results regarding safety, sustainability, and socioeconomic aspects; and (2) a (re-)design phase, which allows guiding principles to steer the innovation process [22]. While the SSbD assessment can be applied to existing chemicals and materials, a great opportunity to apply the framework exists in the context of novel materials that are being developed, as these are still at a low Technology Readiness Level (TRL) (e.g., ideation or lab scale). The flexibility at low TRL in terms of choices for the design and used resources enables the development of materials that align with safety and sustainability criteria, defined by the SSbD framework. The same flexibility does not apply to established materials, making the (re)design of the material itself, as well as the production processes, challenging. Addressing the health risk factors is important, albeit challenging, especially for novel materials since there is usually little available information on toxicological effects due to their novelty. Nevertheless, it is beneficial to apply risk and sustainability assessments from their early design phase that not only align the development of new materials with EU’s Zero Pollution Action Plan and Green Deal but also balance risks and benefits for humans and the environment [23]. The SSbD is an approach aiming at an ex-ante risk factor assessment.

Despite the evident advantages of a successful implementation of an SSbD approach, in terms of prevention-based governance [24] for novel material development, several challenges persist. These include the lack of toxicological information and the practical difficulty of performing an extensive characterization that suits various use phases and life cycles [23]. AdMas and novel materials in general show largely unexplored properties, thus, reliable information regarding their risks for human health and the environment is lacking. In addition, for low TRLs, information regarding the upscaling process is rarely defined, affecting the applicability of risk and sustainability assessment methods. In this study, we review and analyze the SSbD assessment, identifying its challenges and integrating them with the specific details of AdMas development. We offer a course of action to facilitate the (re-)design phase of SSbD, aligning with stakeholders’ interests and showcasing the additional value compared to traditional methods.

2. Advanced Materials

With all the attention they receive from the research community and the materials’ industry, AdMas do not have one unified definition, but rather each agency, body, etc., has developed its own. According to the European Commission (EC), an AdMa is any material that features a series of exceptional properties (mechanical, electrical, optical, magnetic, etc.) or functionalities (self-repairing, shape change, decontamination, transformation of energy, etc.), which can be new or enhanced compared to the conventional materials [23]. The Organisation for Economic Co-operation and Development (OECD) working description for AdMas considers them as innovative materials designed to have new or enhanced properties and structural features, aiming to improve functional performance compared to traditional materials [25]. As shown in Figure 1, there are 9 categories of AdMas according to the OECD, based on their structure. The OECD Working Party on Manufactured Nanomaterials’ (WPMN) works on nanotechnology and plays an important role in developing the guidelines and frameworks that are necessary for the responsible evaluation of manufactured nanomaterials and AdMas. Τhey performed a survey, collecting the views of OECD delegations and experts from various countries via a questionnaire that entailed information on the AdMas sector and categorization. Furthermore, they reviewed the findings from previous efforts in the field of AdMas, e.g., AdMas 3rd conference [26]. Their work led to the development of the working description on AdMas [25]. Their categorization, as shown in Figure 1, mostly follows the results from the aforementioned survey from the OECD [25], but not restrictively since it is an evolving field. For example, biopolymers are naturally occurring polymers designed for specific functionalities (e.g., DNA-based, protein-based, etc.), composites are defined as the combination of two or more materials (e.g., fiber-reinforced composites, particle-reinforced composites, etc.), and metamaterials are defined as materials with properties that go beyond the naturally occurring properties of their components (e.g., electromagnetic metamaterials, acoustic metamaterials, etc.). It is still under discussion between countries and bodies (e.g., OECD) what the characteristics are that make a material advanced, and that is why some parties might not consider several categories from Figure 1 as AdMas [25].

Several categories show promising uses within different sectors, and according to the level of understanding of each material, different options emerge. For example, metamaterials could be used in antenna devices, integrated network sensors, or new superlayers for microwave and terahertz fields [27].

With all the aforementioned prospects, it is also important to consider the challenges that arise regarding AdMas. Notably, novel materials fall outside the scope of existing regulations, posing a significant challenge for agencies worldwide. As a result, efforts are underway to develop new regulations to close the gap and control the potential effects of AdMas on human health, safety, and the environment [28]. For example, nanomaterials pose a potential health concern, as they can enter the human body through the respiratory system and deposit in the respiratory tract or enter the bloodstream and translocate to other organs [29]. However, insufficient information exists on safety concerns, such as fire and explosion risk when using nanomaterials in the form of powder. Nanoscale materials could have a higher risk of explosion than coarse dust depending on surface area and unique properties, yet little research is conducted, resulting in gaps in regulations [30]. Other research concerns include the use of materials in medical applications without knowing their full toxicological profile in the human body [31]. Also, the ability to evaluate the lifecycle of novel materials, such as engineered nanomaterials, without having a complete understanding of their toxicity and bioaccumulation profiles raises concerns within the scientific community and presents challenges in ensuring their sustainability [32]. Nevertheless, it is important to address these issues in the sustainability assessment, as AdMas production, use, and disposal may have significant environmental impacts [33,34], as well as influencing the social, economic, and political aspects.

Because of the considerable gaps in research and knowledge regarding AdMas, in various parts of the lifecycle of the products, research shifts towards more reliable methods for gathering environmental exposure concentrations data [35], for nanomaterials especially, aiming at a global classification and harmonised system. The FAIR (findable, accessible, interoperable, and reusable) data principles [36] are also recommended for nanotechnology data, and recently an interface for human and environmental nanosafety data has been described [37,38]. If no studies are available on the substances under evaluation, a quantitative structure–activity relationship (QSAR) model can potentially give an indication of toxicological hazards such as genotoxicity or mutagenicity [39]. The latest approach in data gathering is the development of Artificial Intelligence and Machine Learning systems that can potentially generate results regarding a chemical’s properties such as 3D structure-shape [40].

The concerns within the scientific community regarding the regulatory framework development also include the ethical and societal dimensions. Potential privacy concerns pose an ethical issue, for example, through the use of flexible electronics in wearable devices that monitor health and communications, among other abilities [28]. Other applications have a significant economic impact within society, like the integration of nanotechnology in cancer treatment, which potentially reduces the quantity of medicine, hospitalization, etc., and at the same time requires interdisciplinary collaboration [28]. However, from an economic point of view, AdMas benefits may be unevenly distributed among society or nations due to their costly research and production process. Furthermore, addressing ethical concerns and ensuring transparent communication regarding the benefits and risks of these materials is crucial [41]. The demand for these AdMa categories is expected to increase in the coming years, both globally and within the EU, where they have crucial strategic importance regarding EU’s resilience, autonomy, and economic security [6].

3. Safe-and-Sustainable-by-Design

3.1. SSbD Background

In 2022, the JRC published a technical report describing the definition of SSbD criteria and evaluation framework for chemicals and materials [20]. The SSbD is a voluntary approach to guide the innovation process for chemicals and materials, and it consists of two distinct phases, the assessment phase and the (re-)design phase, which are performed iteratively along the innovation process for new materials and chemicals, as shown in Figure 2.

As illustrated in Figure 2, the (re-)design phase is applied at every step of the innovation process (e.g., ideation stage, lab-scale stage, pilot-scale phase). This phase involves the definition of certain Design Principles, such as material efficiency, minimization of hazardous chemicals, etc. The Design Principles are applied to the production of the chemical or material under development, in the form of Design Actions, for instance, maximizing the reaction yield or eliminating hazardous input chemicals in the synthesis process. Finally, the outcome of these applied Design Actions is evaluated (assessment phase) using specific Design Indicators, such as the net mass of materials consumed per mass of formed product for a certain reaction, or the biodegradability of the used chemicals. As shown in Figure 3, there are several development stages to apply the (re-)design phase. The initial SSbD assessment system can be (re-)designed through the material’s components, through the main process steps, and even through the final product alteration. The value of (re-)designing is found in its predictive approach that eventually leads to SSbD materials, reducing the necessity for mitigating measures, control actions, and substitution research in later stages.

At the end of each stage’s Design Phase, the SSbD assessment phase takes place by applying the 5-step assessment described by the SSbD framework. First, the intrinsic hazard properties of the chemical or material under investigation are analyzed in Step 1, wherein different criteria are defined based on how hazardous a chemical or material is (i.e., most harmful substances, substances of concern). Depending on the hazard properties, the chemical or material under investigation is given a score, which determines whether it advances to the next step. The most harmful chemicals and materials are rejected during Step 1 and do not proceed to the rest of the assessment. In the second and third steps of the SSbD framework, the human health, safety, and environmental risk aspects of the chemical and material under investigation are examined, focusing on different stages of its life cycle, i.e., the upstream and downstream stages in Step 2, and the use phase in Step 3. During these steps, criteria are determined for the chemical and material under investigation, such as the Risk Characterization Ratio (RCR). The RCR represents the ratio between a calculated or estimated concentration of a hazardous substance and the respective limit [42]. This part of the assessment is conducted across different environmental compartments, stages of the production process, use phase scenarios, etc. Similarly to Step 1, cut-off criteria are selected, wherein materials and chemicals that do not pass a certain acceptable risk level (i.e., a score from Steps 2 and 3) are rejected and do not proceed to the next step of the assessment.

In Step 4, the sustainability assessment is performed, taking into account the entire life cycle of the material and chemical under investigation, using the Life Cycle Assessment (LCA) methodology. Importantly, in comparative assessments, the functionality of different alternatives is considered during Step 4 by calculating a substitution factor for different alternatives as the basis of comparison. Similarly to the previous steps, criteria are determined for the different environmental impact categories. These include achieving a certain percentage of improvement in the environmental impacts of the chemical and material under investigation compared to a reference chemical or material (e.g., a conventional material or a market-average material intended to be replaced by the novel material). However, unlike the previous steps, no cut-off criteria are determined, and therefore a material or chemical is not rejected during this step of the assessment, regardless of its potentially low sustainability score. Finally, Step 5 includes an assessment of social and economic sustainability, and the development of socioeconomic SSbD criteria. This can be achieved using social LCA methodology, including the definition of supply chains, identification of stakeholders, and corresponding impact categories and indicators, as stipulated in the social LCA methodology [43]. For economic criteria, different approaches can be followed, such as Life Cycle Costing (LCC) assessment, a monetary valuation of social and environmental externalities, economic considerations related to material criticality, and interruptions of the supply chain [20]. Unlike Steps 1–4, wherein robust methodologies and established tools are proposed to carry out the assessment, Step 5 is in a relatively more exploratory stage.

At the end of the assessment, an overall SSbD score is calculated based on the individual scores achieved in each step, wherein scores related to safety (i.e., Steps 1–3) are weighed higher than the scores related to sustainability, demonstrating the hierarchical approach of the framework, prioritizing safety aspects over sustainability aspects. Finally, after receiving a final SSbD score, the chemical or material under investigation enters once again the (re-)design phase, wherein Design Principles, Actions, and Indicators are applied with the aim of improving the SSbD score. Overall, by iteratively applying the two phases of the SSbD framework (i.e., assessment and (re-)design phase) along the innovation process and from lower to higher TRL (Figure 3), it is ensured that the final material and chemical that reaches commercial production stages is as safe and sustainable as possible, while maintaining its desired functionality.

In order to test the framework, JRC supported its application to case studies and created a report with the results [44]. In case study 1 of the plasticizer in food contact material that researched the di(2-ethyl hexyl) phthalate (DEHP) alternatives, early from step 1 the lack of harmonised classification of the materials under assessment is identified. According to the SSbD, the materials could not be considered safe due to noncompleteness of the hazard data, so new approach methodologies (NAMs) were used to generate the necessary data (e.g., QSAR). NAMs can be defined as any in vitro, in chemico or computational (in silico) method that can be used to facilitate chemical safety assessment and as a result, minimize the tests on animals [45]. The same challenge identification was stated by BASF and Clariant, the two companies that performed simultaneously case study 2: Flame retardants (halogen-free) in Information and Communications Technology (ICT) products [44]. BASF also pointed out the difficulty of producing the necessary toxicological data related to Step 1 without animal testing, the information gap on the substances regarding use phase related to Step 3, and the data accuracy issue related to Step 4, considering energy consumptions and other variable inputs. Clariant pointed out the difficulty of data gathering for indirect suppliers. Similar observations were made in a case study inside the H2020 SUNSHINE project, addressing the implementation of SSbD for the substitution of Teflon use with alternative coatings of multicomponent nanomaterials (polyfluoroalkyl substances and nanodrops of essential oil) [46]. Based on Tier 1 results, defined as qualitative self-assessment analysis by the industry performed at very early stages aiming to identify hotspots, one company invested into further research and development that would enable the completion of the assessment and further development of the coating.

Since the launch of the framework in 2022, the EU has taken several steps to support its development and actively enhance its applicability in industries. A technical report was published by JRC focusing on criteria selection in July 2022 [20], followed by a period of evaluation starting December 2022. In that period, several initiatives took place, among them a technical report with case studies [44] in June 2023 and the 4th stakeholder workshop in December 2023 on the collected feedback [47], which ended the first reporting period. Another methodological guidance report was published in May 2024 [48] that was followed by feedback collection until the end of August 2024. In December 2024, we anticipate the publication of the second guiding report and the potential revision of the framework based on feedback, according to the EU timeline [49]. Along with the aforementioned actions, the EU provides funding for research on SSbD, promoting collaboration between academia and industry and through them alignment with other EU strategies, such as European Green Deal and Circularity. JRC also provides recommendations on tools that aid with certain parts of the SSbD assessment, such as Chesar [50], Stoffenmanager [51], ECETOC TRA [52], etc. Finally, through the funded projects, several tools with a holistic approach are being developed, such as PARC [53], that aim to facilitate the SSbD assessment in a structured way.

Figure 3. Changes in the initial SSbD system, depending on the nature of the (re-)design. A simplified version focusing on material (re-)design (adapted from [48]).

Figure 3. Changes in the initial SSbD system, depending on the nature of the (re-)design. A simplified version focusing on material (re-)design (adapted from [48]).

3.2. SSbD vs. Current Practices

SSbD was developed to account for both the safety and sustainability aspects in the development of new materials and chemicals in a structured manner, progressing from the separated evaluation via the SbD assessment and environmental evaluation through the LCA. Safe(r)-by-Design (SbD) outlines the principles and actions to include the safety considerations at the early stages of the material or chemical development to minimize the use of hazardous substances and prevent undesirable health and safety risks [54]. The application of the SbD concept has been studied in both the safer design of (nano)materials [55], and the safer design of innovative processes and advanced manufacturing [56]. The original concept extends from the Prevention through Design (PtD) strategic scheme developed by National Institute for Occupational Safety and Health (NIOSH), taking into account the material and occupational hazards, risks, and controls required to minimize the occupational health and safety concerns throughout the life cycle of the process [57]. SbD focuses is an interdisciplinary approach focusing not only on the tools for the safety assessment, but also on establishing a design protocol for knowledge exchange and safety awareness across the actors involved in the material synthesis, manufacturing, use, and end-of-life (EoL) options [58]. SbD assessment involves the substitution of chemicals with safer alternatives, minimization of cytotoxicity and bioaccumulation, improvement of sustainability perspectives (environmental, costing, societal) across the life cycle stages, minimization of waste through circular design, and communication of different stakeholders across the supply chain [58]. Nevertheless, SbD is merely a guiding protocol rather than a structured framework with an appropriate scoring scheme to evaluate the alternative options.

Environmental sustainability is commonly referred to as the climate change potential and carbon footprint through the LCA. LCA was developed based on the ISO 14040:2006 [59] and ISO 14044:2006 [60] Standards providing the guidelines for the goal and scope definition, development of a life cycle inventory analysis (LCI), the life cycle impact assessment (LCIA) phase, and the overall LCA scoring and interpretation. Within the LCA protocol, the potential environmental burdens can be extended to relate to the materials’ value chains “from cradle to grave”, taking into account the raw material extraction, transport, downstream processing, use phase, and EoL. LCA-reported advantages to include the identification of environmental hotspots and aid in early adoption of design actions for sustainable development from low TRL levels [61]. However, the lack of inventory data on material synthesis and downstream processing and details on use and EoL options hinders the over LCA [62]. Additionally, in cases of new material development, extrapolation methods are used for the scaling-up the calculated environmental footprint from the laboratory scale, potentially overestimating the emissions and environmental burdens in the pilot- and industrial-scale processes [61,62,63].

Under European Union (EU) Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation, the established protocol includes the collection and assessment of information on the properties and hazards of materials and chemicals, including toxicological and physicochemical properties [64]. Information gathered through REACH allows the evaluation of risks of chemicals and materials to human health and the ecosystem, while the assessment of the societal benefits or drawbacks and the financial burdens across the materials’ life cycle can be examined via socioeconomic analysis (SEA) [64]. The development of the SSbD framework was based on the REACH principles, integrating all three sustainability aspects (environmental, economic, and social) along with the safety dimensions rather than examining these aspects separately via environmental LCA, LCC, and social-LCA [65]. In that way, the SSbD analyzes the alternative opportunities in terms of design scenarios and chemicals to minimize the health hazard and maximize sustainability.

It is interesting to compare the EU’s practices and efforts towards safer and more sustainable materials with other methodologies. The United States of America (USA) follows separate protocols from Occupational Safety and Health Administration (OSHA) [66], National Institute for Occupational Safety and Health (NIOSH), and other nonprofit bodies. As expected, while there may be differences in the existing regulations between Europe and the USA, the established methodologies for risk and sustainability assessment are very similar. However, there is no evidence of enforcing a holistic approach like SSbD framework yet. It is also worth mentioning that research between Europe and Asia shows a negative association between the connectivity of countries and environmental sustainability indexes. It is argued that connectivity between countries, meaning collective measures, shared metrics, etc., contribute to sustainability goals achievement. Evidently, although more connected and usually wealthier countries incorporate more progressive environmental policies, they also have higher resource consumption and release more hazardous emissions [67].

4. SSbD in Advanced Materials Ecosystem

4.1. SSbD (Re-)Design Phase: Principles, Actions, and Indicators

A first consideration during the (re-)design phase is to define the level of the design: (a) molecular design; (b) product design; and (c) process design. The molecular design includes the design of new materials based on the atomic-level description of the molecular system and delivers an entirely new material. The product-level design focuses on the design of a final product, in which the material under investigation is used to serve a specific function. At the process level, while the intrinsic properties of the material do not change, the processing at any stage of the lifecycle of the material can be (re)designed, from the selection of raw materials to the end of its lifecycle, in an effort to make it safer and/or more sustainable [20]. In the context of AdMas, all three levels of design may be considered for SSbD assessment, for example, when new AdMas are being developed at the molecular level [68,69,70], a final product is being (re)designed to include AdMas [5,71,72], or an upstream/downstream process in the life cycle of the AdMas is being altered [73,74,75].

Depending on the level of Design, appropriate Design principles, actions and indicators (collectively referred to as “design parameters” here) need to be selected. The SSbD framework [20] proposes a nonexhaustive list of possible design parameters, which can be based on principles of green chemistry [76], green engineering [77], circularity [16], sustainable chemistry criteria [20], and principles of SbD [78]. Additional or alternative design parameters can be developed by the SSbD practitioner, considering, for example, additional principles (e.g., Benign by Design principles, [79]) based on the specific sector and material under assessment, as well as the particular application of the material. A preliminary identification of hotspots along the material’s lifecycle can further contribute to the definition of design parameters [48]. Such hotspots could be an identification of the lifecycle stages expected to be affected the most by the investigated innovation, or any variations compared to the original system to fulfill the investigated action (e.g., different amount or type of chemicals/formulations etc.).

In order to propose a suitable list of (re-)design parameters, in addition to the principles and criteria already proposed in the SSbD framework, SSbD practitioners may pose the following questions. For each question, an explanation or example is provided of possible (re-)design principles, particularly related to AdMas.

• What is the material under assessment (e.g., name, composition, numerical identifiers, molecular structure, properties)?

The intrinsic properties and structure of the material are pivotal for the determination of its safety and sustainability. For example, in the case of AdMas nanomaterials, the structural and surface properties can be a predictor for their potential toxicity [80]. Therefore, (re-)design principles, particularly for molecular design, can be defined based on specific structural and surface aspects with a known or predicted high toxicity potential, linked with design actions that aim to minimize the formation of materials with said properties.

2.

What is the final product or application associated with the material (e.g., product function, description, sector, value chain)?

Information regarding the final product and the envisioned function of the material in the product are essential to determining relevant parameters in the (re-)design phase of products that incorporate or use said materials. For example, self-healing AdMas have been applied to several different products, such as wearable devices, electronics, and electrochemical devices, with different applications bringing forward different requirements for the properties and functionality of the incorporated AdMas [81]. Identification of product-specific requirements can help define specific (re-)design principles related to maximizing the functionality of the AdMas while minimizing the risk and sustainability concerns, particularly under the anticipated operational conditions based on the envisioned application (e.g., temperature, humidity, skin contact).

3.

What are the processes involving the material along the value chain of the product (e.g., is the material an intermediate, component, part of the final product) and what is the relation with possible exposure routes for people and the environment along its entire value chain?

Specific exposure scenarios to the AdMas along their lifecycle, and consequently risk and safety aspects, will depend on the processes involved in the production and EoL phase of the material or product (e.g., processing conditions such as temperature, and associated protective measures such as ventilation). This is also true during the use phase of the material (or final product) by consumers. Specific (re-)design parameters can be proposed by taking into account the material’s processing along its lifecycle. For example, volatility of involved components at elevated temperatures during heat treatment or high-temperature operation [82,83]. Finally, depending on whether the AdMas are incorporated in the final product or only used as precursors during upstream production, proposed (re-)design principles can focus on specific production processes that constitute hotspots. They may also address unanticipated exposure for humans and the environment via the final product during various life cycle stages [84,85]. Such exposure may have high hazard potential as no protective anticipating or mitigating measures are taken.

4.

What stakeholder groups are involved along the value chain of the material (e.g., direct contact during manufacture, upstream/downstream suppliers, users, indirectly affected actors)?

The identification of relevant stakeholders along the entire value chain is very important to identify all potential health and environmental risks and exposure scenarios and to perform the sustainability assessment, as it is an integral part of social LCA [43]. Mapping the relevant stakeholder groups during the (re-)design phase can be a valuable source of possible (re-)design parameters, as it helps to identify the most vulnerable stakeholders along the value chain. Once identified, they can be prioritized in terms of safety and sustainability while setting (re-)design indicators. For example, this could lead to the definition of a strict maximum allowable concentration of certain harmful chemicals per mass of product, considering potential exposure of children or people with existing health conditions (e.g., for AdMas in plastics that may be used for consumer products or medical devices that may be used by patients). On the contrary, such strict criteria may be less important for AdMas that are only used during manufacture and do not end up in a consumer product, assuming that only specialized personnel trained in Good Manufacturing Practices (GMP) and Occupation Health and Safety would be in contact with them.

5.

What conventional materials are substituted by the new material under assessment (same functionality for same product and use case) and how are sustainability and safety aspects expected to be affected by the substitution along the lifecycle?

The desired functionality of the AdMas should be defined considering what is the existing material being replaced by the AdMas. SSbD practitioners can consider what is the motivation behind the development and use of the AdMas to replace a conventional material, in order to define relevant (re-)design parameters. For example, in the case of bio-based structural materials, aiming to replace petroleum-based plastics [86], (re-)design principles could involve the percentage of nonrenewable sources incorporated in a product, or a circularity index, if the source of bio-based materials is residues from other value chains. In the case of biodegradable electronics involving AdMas, which aim to replace conventional electronics with complicated EoL treatment phases [86], (re-)design principles could be envisioned involving the biodegradability potential. These properties should also inspire (re-)design principles aiming to minimize adverse effects and problem-shifting from the replacement of conventional materials with AdMas, such as the adverse environmental impacts and associated health risks of biobased materials [87,88] or the challenges associated with biodegradable electronics [89,90,91].

6.

What is the geographic range along the material’s life cycle (e.g., country/region of sourcing raw materials, production, use, EoL treatment)?

When assessing the sustainability (environmental, social, economic) of a certain material or product, the geographic distribution of resources and processes can play a significant role [92,93,94]. Taking into account the envisioned geographical distribution of resources and processes can help define some specific (re-)design parameters to prevent, for example, high environmental impacts due to the transportation of goods, while promoting the selection of local sources for materials (e.g., setting a principle related to the percentage of materials sourced from the same continent, or an indicator related to the total transport distance of components used to manufacture a material). Similarly, (re-)design parameters could be considered that maximize the safety and social sustainability of the AdMas, by promoting the sourcing of materials and labor in locations with higher adherence to safety standards in the workplace, or the equal employment opportunities of different groups (e.g., setting principles and indicators related to the percentage of women or children employed along the value chain, the number of work accidents or violations of safety standards in a certain facility or location). Finally, considering the geographical distribution of resources, particularly for critical materials with limited geographical distribution, (re-)design parameters can be set to minimize the risk of interruptions in the supply of materials due to geopolitical reasons [95,96], such as in the case of war or natural disasters (e.g., setting principles and indicators related to the diversification of sources).

7.

Which Sustainable Development Goals (SDGs) are expected to be affected along the lifecycle of the material?

AdMas have been proposed to improve several aspects of life, such as improving the environmental, social, and economic sustainability, and decreasing the risks to human health and the environment [54,97,98]. In an attempt to ensure material developments following a holistic approach, wherein both safety and sustainability are taken into account during the (re-)design phase, SSbD practitioners may consider how the new AdMas under investigation have the potential to contribute towards the United Nations’ (UN) SDGs [99]. For example, along the value chain of novel AdMas, SDG 9 (build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation) could be considered to set certain (re-)design indicators, such as the proportion of small-scale industries in the value chain, in an attempt to contribute towards SDG Target 9.3 (increase the access of small-scale industrial and other enterprises, in particular in developing countries, to financial services, including affordable credit, and their integration into value chains and markets).

8.

What are the relevant regulatory frameworks, standards, and voluntary certification schemes or standards for the material and for other chemicals, resources, products, and processes along its value chain?

The regulatory framework is ought to be considered already during the material ideation stage, as failure to comply with the specific regulations and standards would render the material nonuseable for this envisioned application. For example, wearable electronics and medical devices ought to meet specific requirements regarding the grade and purity of the materials used in their production [100]. Therefore, (re-)design parameters should be defined to ensure compliance with these specifications. Besides regulatory requirements, there are voluntary certification schemes that may be relevant for the AdMas under development, or the specific sector and application scenario envisioned for it. While not mandatory, adherence to voluntary certification schemes, such as green labels or sustainable sourcing of material certifications, may improve the market prospects of the material. Furthermore, incorporating such criteria in the (re-)design phase allows to anticipate potential requirements that are currently voluntary, but may become mandatory in the future. For example, the EU ecolabel [101] criteria for electronic devices [102] could be used to define product (re-)design principles regarding the content percentage of at least 10% for recycled plastics, or the responsible sourcing of certain metals and ores from certain areas for AdMas incorporated in electronic devices. A similar rationale for selecting based on regulatory requirements and voluntary certification schemes can be considered for other materials and chemicals used along the value chain of the AdMas under assessment.

9.

What are previously identified safety and sustainability impact hotspots for this material/sector/similar materials (in terms of production, composition, functionality)?

Based on previously identified hotspots of impacts for both sustainability and safety, SSbD practitioners can ensure that the use of certain compounds and processes is avoided or minimized to the extent possible, or that countermeasures are taken to decrease their overall impact. Several examples of assessments exist in scientific literature for AdMas [103,104,105,106,107,108,109], which could serve as inspiration for the development of newer, safer, and more sustainable materials in the future. For example, an SSbD screening strategy is implemented on four building insulation materials. They are tested on performance, potential inhalation risk during installation (related to Step 2 of SSbD assessment), potential exposure during the use phase (related to Step 3 of SSbD assessment), and biodissolution (related to Steps 3 and 4 of SSbD assessment), among others, using simulation and modeling tools on three realistic exposure scenarios [104]. Di Battista et al. show the value of a solid screening process towards SSbD materials in low TRLs and how investments can be driven to safer, more sustainable, and economically viable materials. Another practical example, implements traditional risk assessment methodologies, such as the French Agency for Food, Environmental and Occupational Health & Safety method (ANSES), from France; Control Banding Nanotool (CB Nanotool), from the United States of America—National Institute for Occupational Health and Safety (NIOSH); Stoffenmanager Nano, from the Netherlands, etc., for carbon nanotubes (CNT) [109]. Sousa et al. focus on different methodologies for control banding (related to Step 1 of SSbD assessment) and underline the importance of in-depth assessment of materials that have intrinsic properties hazardous for human health. Furthermore, the value of future integration with LCA and SbD methodology is mentioned to provide a more holistic approach to health, safety, and sustainability aspects. One more practical example that focuses on the LCA (related with Steps 3 and 4 of SSbD assessment) of functional ceramics, such as piezoelectrics, thermoelectrics, etc. [107]. Smith et al. examine traditional LCA applications, including environmental profiling of functional ceramics. They highlight the importance of implementing LCA in early design stages, which can potentially help to avoid expensive investments by identifying hotspots and testing alternatives and possible optimizations.

While the above list of questions is not exhaustive, it can help guide SSbD practitioners towards the development of a comprehensive initial list of (re-)design aspects, taking into account safety and sustainability (environmental, economic, and social) aspects along the entire value chain of the material under investigation. These design aspects can be further refined during the SSbD assessment process, wherein more specific hotspots of safety and sustainability risks are identified and subsequently targeted for mitigation during ensuing (re-)design phase iterations.

4.2. Value Chain, Logistics, and Stakeholders

The development and commercialization of AdMas involves a complex value chain, from raw material sourcing to final product distribution and EoL management. A thorough understanding of this value chain is critical to optimizing the production process, ensuring sustainability, and aligning with stakeholder interests. The integration of SSbD principles adds complexity to the value chain. Safety, environmental impact, and circularity must be factored in at every stage. This holistic approach ensures that AdMas not only meet performance and market demands, but also adhere to stringent standards of sustainability and responsible innovation.

From a logistics perspective, efficient transportation of raw materials plays a critical role in minimizing the environmental footprint. This includes the reduction of transportation-related emissions through optimized routes, low-energy transport methods, and sourcing materials as locally as possible. The SSbD framework encourages manufacturers to select materials that minimize the environmental impact of both extraction and transportation, promoting local sourcing and the use of renewable or recycled materials whenever feasible [20,110].

Once produced, AdMas are typically integrated into larger systems, such as electronic devices, automotive components, or renewable energy infrastructure (e.g., wind turbines, solar panels) [111]. This integration phase is where the material’s functional performance is tested against its intended application. At this stage, stakeholders must ensure that materials meet stringent quality standards, reliability, and safety regulations, especially for critical sectors like healthcare, aerospace, and electronics [112]. Logistical concerns at this stage often revolve around the supply of components and the distribution network. The use of digitalization and smart logistics systems is essential for optimizing supply chains, allowing real-time tracking of materials and efficient route optimization, which reduces environmental impacts and minimizes delays [113,114].

For industrial stakeholders, AdMas represent significant potential, recognized for their pivotal role in driving competitiveness, sustainability, and technological advancement. Active participation in European initiatives such as Horizon 2020 and Horizon Europe highlights the strategic importance of AdMas in promoting green and digital transitions while maintaining a competitive edge in the global market [41]. Stakeholders within EU, following the European strategic research and innovation agenda for the next generation of AdMas [115], potentially emphasize their role in the green and digital transitions, which are pivotal for meeting the EU’s sustainability goals. They recognize the importance of AdMas development, however, they highlight the importance of bridging the gap between research and market application, especially in crucial sectors like energy, electronics, construction, and mobility [116].

The processing stage of AdMas transforms raw materials into functional products through energy- and resource-intensive steps like blending, surface modifications, and deposition techniques. The SSbD framework highlights the need for process efficiency, aiming to reduce energy consumption, waste, and the use of hazardous chemicals. Key stakeholders in this phase include material suppliers, who provide raw components; manufacturers, responsible for production and modification using methods like reactive extrusion or low-energy synthesis; and regulators, ensuring compliance with safety and environmental standards, especially in high-risk sectors like nanotechnology and aerospace [54].

In addition, incorporating SSbD principles into the value chain requires focusing not only on the production and use phases but also on the end-of-life stage of materials. Advanced materials must be designed with circular economy principles in mind, enabling recycling, reuse, or safe biodegradation at the end of their lifecycle [54]. This includes designing for disassembly, where complex products like electronics or renewable energy systems can be easily broken down, and valuable materials can be reclaimed. The logistics of waste management play a critical role here, particularly in ensuring that end-of-life products are efficiently collected, sorted, and processed. Innovations in reverse logistics, where materials are returned to manufacturers for recycling or safe disposal, are essential for reducing the environmental footprint of AdMas [65]. Industrial stakeholders recognize the need for substantial investment, coordinated efforts, and supportive policies to unlock the full potential of these materials [117].

Summarizing, it is important to underline the necessity for stakeholders’ alignment on safety and sustainability goals in order to achieve the creation of SSbD products. SSbD promotes interdisciplinary collaboration because experts from different fields, such as science, safety, sustainability, and economy, should provide their input to conclude an assessment. The industrial stakeholders can have an important pull towards SSbD, for they are immediate receivers of most of the benefits of adopting SSbD practices. For example, innovation steered by SSbD can lead to products with improved performance and functionality through the (re-)design phase. Every stakeholder in a product’s value chain, by prioritizing sustainability, will not only enhance his company’s appeal for consumers, but also provide alignment with EC’s future regulation goals. Furthermore, he ensures the production of more sustainable products in a safe manner and taking into consideration every socioeconomic aspect that, in the long term, ensures the company’s viability and prosperity. The success of the SSbD application is connected to stakeholders’ engagement with the procedure and their comprehensive understanding of their role in the SSbD ecosystem.

4.3. SSbD and Advanced Materials and Challenges

With the general goal to ultimately develop new safe and sustainable by-design materials, it is logical to prioritize understanding the applicability and limitations of the methodology at a low TRL. The hierarchy of controls, presented in ISO 45001:2018 [118], introduces a systematic approach for the reduction of risk by grouping control measures in five categories of declining effectiveness. The most effective category is the elimination of a hazard, followed by the substitution with less hazardous substances. By extending the logic behind this hierarchy of actions to the whole SSbD methodology (risk and sustainability factors), we conclude that the most effective route of action is the elimination of a hazard followed by the substitution, which are more easily implemented in early design stages rather than high TRLs. This approach aligns with the elevated interest in AdMas due to their enhanced properties and offers the advantage of tackling potential safety and sustainability issues in the early stages, saving resources (working hours, raw materials, utilities) in research and development. However, low TRLs are accompanied by a lack of information, especially toxicological analysis, that is crucial to conducting a robust assessment of the developing material.

On the other hand, as TRL increases, providing more accurate and detailed information, the room for improvement decreases in comparison with the early design phase and with respect to the material’s functionality. Implementing SSbD within the design process should be viewed as an evaluation of a case oriented on best available knowledge and data rather than a complete assessment. The advantages of the evaluation are establishing comparative benchmarks, driving data collection for later assessments, and ultimately driving material researchers to design more sustainable AdMas [119].

The greater challenge that the materials’ research community needs to tackle is the data availability, accessibility, and quality. As analyzed in Section 2, utilizing FAIR data for an informed SSbD assessment fosters informed decision-making throughout the early design phases of advanced materials. While it is important to promote the development of digital tools and SSbD toolboxes, such as the EC-funded PARC project (Partnership for the Assessment of Risks from Chemicals), that aim to increase the availability of FAIR data [120], NAMs can also aid in delivering improved chemical safety assessment [45].

The SSbD methodology offers a proactive approach in comparison to the often more reactive approach that traditional risk assessment and LCA methodologies do. It aims to integrate safety and sustainability principles early in the design phase, focusing on preventive measures rather than mitigating actions in later stages, which traditional risk assessment usually does. Furthermore, SSbD promotes research and development of novel materials, creating opportunities for novel functionalities and applications, as well as manufacturing processes that drive industries to shift towards safer and more sustainable solutions. New regulatory frameworks and policies can also be integrated with SSbD assessment, using the same scoring system, supporting future compliance in a holistic approach that separate assessments cannot offer. The simultaneous assessment of safety, environmental, economic, and social aspects offers a more robust result, in contrast with individual assessments that have narrower limits of applicability and tend to result in selection between compliance with either safety or sustainability aspects. Finally, SSbD is a multidisciplinary approach that requires joint efforts from experts in different fields, compared to the individual assessments that are more discipline-specific. That is an advantage in terms of collaboration and can even create career opportunities as a social effect, but it is also a challenge to approach effectively.

5. Concluding Remarks and Future Perspectives

In this analysis, we tried to connect the value of SSbD with the AdMa’s sector, after overviewing the sector in general, stating its importance in materials and technology applications as well as their particular characteristics. A brief overview of the framework with emphasis in the two phases of the SSbD assessment, the (re-)design and the assessment phase, provided guidelines with specific examples for applying the (re-)design phase in a new material development process. The identified challenges for applying SSbD on AdMas as well as the stakeholders’ interests were underlined in order to provide with potential resolutions. The main limitation that needs to be addressed is data availability and quality especially, for novel materials.

Besides the identified challenges and limitations that the materials’ industry faces in order to incorporate the SSbD assessment, the EU incentives towards safer and more sustainable material development are clear. AI and ML systems are gradually more involved in future initiatives [121] and can potentially lead to the development of informed decision-making tools, which can facilitate the development of SSbD materials without compromising their intended functionality. By modeling the material composition and life cycle impacts, computer-based analysis can be performed to test alternatives and guide the research towards safer and more sustainable options before moving to higher TRLs. These technologies receive more and more interest from the research community as well as the manufacturing industry. In chemistry, research shifts towards digital solutions that signify the transition from empirical, labor-intensive research towards a more predictive, efficient, and fast approach [122]. Combined with traditional approaches, they will facilitate the implementation of Step 1 of SSbD assessment that is based on the intrinsic properties of the substances. In the manufacturing sector, Industry 4.0 technologies, such as predictive AI algorithms and digital twin (DT) simulation, can provide real-time data by process monitoring and aid in occupational risk assessment. For example, the utilization of DT systems can provide process isolation, where operators are not present in the physical environment and simulations and controls can be performed, checked, and optimized in the virtual domain [123]. Besides facilitating the implementation of Step 2 of SSbD assessment that focuses on the production phase of the lifecycle of the product, in some cases they will also aid in the application of Step 3 that focuses on the use phase. In general, real-time monitoring, defect detection, and digital twins are operating as sensors in manufacturing environments that feed machine learning models with data to improve the production process in real time. These technologies can also feed the Life Cycle Inventory (LCI) with continuous data that will support the analysis via LCA, instead of using predefined databases [124]. In that way, parts of Step 3 and Step 4 of the SSbD assessment will be facilitated.

Collaboration among stakeholders (industries, researchers, and policy-makers) anticipation of regulatory demands, and a commitment to sustainability are pivotal for translating SSbD into tangible advancements. To fully leverage the potential benefits that innovative AdMas offer, it is essential to prioritize addressing safety and sustainability aspects. As AdMas earn more space in the industry, the need for collaboration between experts to create standardized approaches that will facilitate the development of SSbD materials increases. Ultimately, as materials science continues to evolve, incorporating SSbD principles will enable the development of high-performance, low-impact materials that will align with EU’s goals to minimize health and environmental risks.