# Safe, sustainable and recyclable by design (SSRbD): A qualitative integrated approach applied to polymeric materials early in the innovation process

Lya G. Soeteman-Hernandez, Géraldine Cabrera, Arrate Huegun, Pablo

Outón, Sebastien Artous, Stephanie Desrousseaux, Yvonne Staal, Virginia

Cazzagon, Camilla Delpivo, Daniel Ganszky, et al.

► To cite this version:

Lya G. Soeteman-Hernandez, Géraldine Cabrera, Arrate Huegun, Pablo Outón, Sebastien Artous, et al.. Safe, sustainable and recyclable by design (SSRbD): A qualitative integrated approach applied to polymeric materials early in the innovation process. Sustainability & Circularity NOW, 2025, 2025 (02), pp.a25547325. 10.1055/a-2554-7325. cea-05124692

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# Sustainability & Circularity NOW

## Safe, sustainable and recyclable by design (SSRbD): A qualitative integrated approach applied to polymeric materials early in the innovation process

Lya Soeteman-Hernández, Géraldine Cabrera, Arrate Huegun, Pablo R. Outón, Sébastien ARTOUS, Stephanie Desrousseaux, Yvonne Staal, Virginia Cazzagon, Camilla Delpivo, Daniel Ganszky, Simon Clavaguera.

Affiliations below.

DOI: 10.1055/a-2554-7325

**Please cite this article as:** Soeteman-Hernández L, Cabrera G, Huegun A et al. Safe, sustainable and recyclable by design (SSRbD): A qualitative integrated approach applied to polymeric materials early in the innovation process. Sustainability & Circularity NOW 2025. doi: 10.1055/a-2554-7325

**Conflict of Interest:** The authors declare that they have no conflict of interest.

This study was supported by HORIZON EUROPE Digital, Industry and Space (http://dx.doi.org/10.13039/100018699), 101057901

**Abstract:**

The safe and sustainable by design (SSbD) concept integrates functionality with safety and sustainability aspects at an early phase of the innovation and product development process. A qualitative integrated safe, sustainable-and-recyclable-by-design (SSRbD) approach was developed in a series of co-creation workshops involving risk assessors, toxicologists, eco-design and sustainable development experts. The SSRbD approach consists of: 1) the identification of functionality, criticality, toxicity, environmental, social, circularity/recyclability, and economic impacts in a life cycle thinking perspective; 2) the development of SSRbD strategies; and 3) verification of SSRbD strategies. This first 2 steps were applied to three case studies (Building sector: New recyclable-by-design bio-sourced polyurethane (PU) to replace PVC (Polyvinyl Chloride) as insulating material for window frames; Transport sector: Fire resistant, intrinsically recyclable epoxy-vitrimer materials for sustainable composites to replace metal for train body; and Packaging sector: Recyclable MultiNanoLayered (MNL) films to replace multi-layer films for packaging with drastically reduced concentrations of compatibilizers). A guidance for identifying polymer material relevant information needs was developed. In terms of internal organization, an interdisciplinary group for case study assessment was developed. Each case study comes with challenges and needs, which is why a tailor-made approach is required for application of SSRbD of polymeric materials and products.

**Corresponding Author:**

Dr. Lya Soeteman-Hernández, National Institute for Public Health and the Environment (RIVM), Center for Safety of Substances and Products, Antonie van Leeuwenhoeklaan 9,, 3721 MA Bilthoven, Netherlands, lya.hernandez@rivm.nl

**Contributors' Statement:** Author contributions:

Conceptualisation – L.G. Soeteman-Hernández, G. Cabrera, A. Huegun, P.R. Outon, S. Artous, S. Clavaguera

Writing – original draft – L.G. Soeteman-Hernández, G. Cabrera, A. Huegun, P.R. Outon, S. Artous, S. Desrousseaux, V. Cazzagon, C. Delpivo, D. Ganszky, S. Clavaguera

Writing – review &amp; editing – L.G. Soeteman-Hernández, G. Cabrera, A. Huegun, P.R. Outon, S. Artous, S. Desrousseaux, Y. Staal, V. Cazzagon, C. Delpivo, D. Ganszky, S. Clavaguera

Funding acquisition – S. Artous, S. Clavaguera
Affiliations:

Lya Soeteman-Hernández, National Institute for Public Health and the Environment (RIVM), Center for Safety of Substances and Products, Bilthoven, Netherlands

Géraldine Cabrera, IPC, Industrial Technical Centre for Plastics and Composites, Materials & Recycling, Bellignant, France
Arrate Huegun, CIDETEC, Polymers & Composite, Donostia-San Sebastian, Spain

[...]

Simon Clavaguera, CEA de Grenoble, DES/LITEN/DTNM, Grenoble, France

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# Safe, sustainable and recyclable by design (SSRbD): A qualitative integrated approach applied to polymeric materials early in the innovation process

OPEN
ACCESS

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## Authors

Lya G. Soeteman-Hernandez¹, Géraldine Cabrera², Arrate Huegun³, Pablo R. Outón⁴, Sébastien Artous⁵, Stephanie Desrousseaux⁵, Yvonne Staal¹, Virginia Cazzagon⁶, Camilla Delpivo⁶, Daniel Ganszky⁷, Simon Clavaguera⁵

## Affiliations

1. National Institute of Public Health and the Environment (RIVM), 3721 MA Bilthoven, NL

2. IPC, Industrial Technical Centre for Plastics and Composites, Bellignat, France

3. CIDETEC, Paseo Miramon, P.º de Miramón, 196, 20014 Donostia-San Sebastian, Gipuzkoa, Spain

4. INDRESMAT, Ctra. del Mig, 75, 08907 L'Hospitalet de Llobregat, Barcelona, Spain

5. Univ. Grenoble Alpes, CEA, Liten, DTNM, 38000 Grenoble, France

6. LEITAT Technological Center, C/ de la Innovació, 2, 08225 Terrassa, Spain

7. Geonardo Environmental Technologies Ltd. (GEO), 1031 Budapest, Hungary

## SIGNIFICANCE (max 590 characters)

A qualitative integrated safe, sustainable and recyclable-by design (SSRbD) approach was developed to bring together functionality with safety, sustainability and recyclability aspects. The approach consisted of three steps: 1) The identification of functionality, criticality, toxicity, environmental, social, circularity, and economic impacts in a life cycle thinking perspective; 2) The development of SSRbD strategies; and 3) Verification of SSRbD strategies. The first two steps in the SSRbD approach were applied to three case studies in the building, transport and packaging sectors.

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## Keywords

innovation, safety, sustainability, recyclability, polymeric materials, integrated approach, SSbD

submitted

accepted after revision

accepted manuscript online

published online

## Bibliography

Sus. Circ. NOW 2023; x: SCNOW-0000X

DOI 10.1055/XXXXXXX

eISSN 0303-4259

© 2023. The Author(s).

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This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).

Georg Thieme Verlag KG, Rüdigerstraße 14, 70469 Stuttgart, Germany

## Correspondence

Lya G. Soeteman-Hernández

lya.hernandez@rivm.nl

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Additional material is available at

https://doi.org/10.1055/SNOW-0000X.

## ABSTRACT

The safe and sustainable by design (SSbD) concept integrates functionality with safety and sustainability aspects at an early phase of the innovation and product development process. A qualitative integrated safe, sustainable-and-recyclable-by-design (SSRbD) approach was developed in a series of co-creation workshops involving risk assessors, toxicologists, eco-design and sustainable development experts. The SSRbD approach consists of: 1) the identification of functionality, criticality, toxicity, environmental, social, circularity/recyclability, and economic impacts in a life cycle thinking perspective; 2) the development of SSRbD strategies; and

This article is protected by copyright. All rights reserved.
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3) verification of SSRbD strategies. This first 2 steps were applied to three case studies (Building sector: New recyclable-by-design bio-sourced polyurethane (PU) to replace PVC (Polyvinyl Chloride) as insulating material for window frames; Transport sector: Fire resistant, intrinsically recyclable epoxy-vitrimer materials for sustainable composites to replace metal for train body; and Packaging sector: Recyclable MultiNanoLayered (MNL) films to replace multi-layer films for packaging with drastically reduced concentrations of compatibilizers). A guidance for identifying polymer material relevant information needs was developed. In terms of internal organization, an interdisciplinary group for case study assessment was developed. Each case study comes with challenges and needs, which is why a tailor-made approach is required for application of SSRbD of polymeric materials and products.

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# 1. Introduction

The safe and sustainable by design (SSbD) concept is central to European Commission's (EC) Chemicals Strategy for Sustainability (CSS) aiming to innovate for safe and sustainable chemicals and at achieving safe products and non-toxic material cycles [1]. SSbD identifies safety and sustainability hotspots at an early phase of the innovation and product development process in order to minimize potential hazard(s) and/or exposure and to maximize sustainability [2]. SSbD ensures that newly developed materials integrate functionality with safety and sustainability from the innovation phase through to the final product.

The European Commission (EC) Joint Recent Centre (JRC) has published several reports on SSbD including: i) a review of safety and sustainability dimensions, aspects, methods, indicators and tools [3]; ii) the SSbD framework for the definition of criteria and evaluation procedure for chemicals [4]; iii) the application of SSbD framework to case studies [5]; and iv) the SSbD chemicals and materials methodological guidance [6]. The aim of the SSbD framework is to support the design and development of safe and sustainable chemicals and materials with research and innovation (R&I) activities. A recommendation was also published by the Commission in the Official Journal of the European Union in December 2022 [7]. The EC JRC SSbD framework is a voluntary approach to guide the innovation process for chemicals and materials. The aims of the SSbD framework is to i) steer the innovation process towards the green and sustainable industrial transition; ii) substitute or minimise the production and use of substances of concern, in line with, and beyond existing and upcoming regulatory obligations; and iii) minimise the impact on health, climate and the environment during sourcing, production, use and end-of-life of chemicals, materials and products [4]. The SSbD framework is composed of a (re-)design phase and an assessment phase that are applied iteratively as data becomes available. The (re-)design phase consists of the application of guiding principles to steer the development process. The goal, the scope and the system boundaries, which will frame the assessment of the chemical or material, are defined in this phase. The assessment phase comprises of 4 steps: hazard, human and the environmental exposure during production and use, and life-cycle assessment. The assessment can be carried out either on newly developed chemicals and/or materials, or on existing chemicals and/or materials to improve their safety and sustainability performance during production, use and/or end-of-life [4]. Some examples where SSbD has been applied include a plasticiser (non-phthalate) in food contact material, flame retardants (halogen-free) in information and communication technology products, surfactants in textiles [5], nano-silver-based antimicrobial textile coatings production [8], battery materials [9], nano-enabled PFAS (Polyfluoroalkyl substances)-free anti-sticking coating for bakery molds, and nano-drops of essential oil anchored to the surface of nano clays and encapsulated in a polymeric film [10].

Industry (mainly the European Chemical Industry Council, Cefic) also support the SSbD concept and also have published several reports on SSbD. These focus on how SSbD can be implemented to boost innovation and growth within the European chemical industry [11] and how SSbD acts as a transformative power behind circular and climate neutral innovations [12]. Cefic has recently also developed a guidance to unleash the transformative power of innovation [13]. Here guiding design principles were proposed for a selected set of safety and

sustainability considerations or dimensions to be assessed at the level of product-application combination in a stage-gate-like approach during innovation. The basic principle when innovating to improve the functionality and performance of chemicals, materials, products, processes or services, is to advance in at least one of the dimensions of safety and sustainability without causing significant negative impacts in any of the other dimensions [13].

Plastic waste poses various risks to public health and the environment, while in 2019, 22 million tonnes of plastic were released into the environment, a figure that is expected to double by 2060 according to the OECD [14]. Danger of endocrine disruption, land, air, and water pollution are only some of the adverse effects of plastic waste on public and environmental health. Still, 70% of plastic waste collected in Europe is landfilled or incinerated [15, 16]. In this study, the SSbD concept has been expanded with extra emphasis on recyclability as this is still a major shortfall for many polymeric materials, while at the same time a necessary path towards circularity [17]. The EC JRC SSbD framework [4] covers recycling partly within the SSbD design principles SSbD1 Material efficiency, SSbD4 Use renewable sources, SSbD7 Design for end-of-life (Avoid using chemical/materials that hamper the recycling processes at end-of-life) and SSbD8 Consider the whole life cycle (Consider the most likely use of chemical/material and if there is the possibility to recycle it); yet extra attention is needed to the use phase and life cycle of the product. For this reason, the SSbD framework has been modified with special attention to recyclability into the safe, sustainable, and recyclable by design (SSRbD) integrated approach. This update was done in anticipation to going beyond material and process, and to focus on the lifecycle of future products with extra emphasis for end-of-life (EoL). This approach focuses not only in content but also in developing multi-disciplinary teams which brings several disciplines together including material and process scientists, hazard assessment experts, toxicologists and environmental impact specialists. This is especially important for plastics which are being predominantly made from fossil feedstock with critical issues with EoL (mostly landfilled or incinerated). An SSRbD integrative approach was developed and applied to three case studies involving polymeric materials in the building, transport and packaging sector.

# 2. Methodology

## 2.1 Development of SSRbD Integrative Approach

Reports from the EC JRC [3-6], Cefic publications [11-13] and SSbD case studies [5, 8-10] were considered for the development of the integrative SSRbD strategy. The SSbD concept may be considered as the identification of sustainability (safety, risks concerning humans and the environment, environmental, social and/or economic impacts) hotspots at an early phase of the innovation and product development process in order to minimize potential hazard(s) and/or exposure [3], and to maximize sustainability. A first description of the SSbD concept can be found in the EU - CSS: "safe and sustainable-by-design can be defined as a pre-market approach to chemicals that focuses on providing a function (or service), while avoiding volumes and chemical properties that may be harmful to human health or the environment, in particular groups of chemicals likely to be (eco) toxic, persistent, bio-accumulative or mobile. Overall sustainability should be ensured by minimizing the environmental footprint of chemicals in particular on climate change, resource use, ecosystems and biodiversity from a life cycle perspective" [4].
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The 'by-design' or (re)design phase consists of SSbD principles including: i) SSbD1 Material efficiency; ii) SSbD2 Minimise the use of hazardous chemicals/materials; iii) SSbD3 Design for energy efficiency; iv) SSbD4 Use renewable sources; v) SSbD5 Prevent and avoid hazardous emissions; vi) SSbD6 Reduce exposure to hazardous substances; vii) SSbD7 Design for end-of-life; viii) SSbD8 Consider the whole life cycle [4].

In the context of the framework of SSbD criteria definition for chemicals and materials, the EC-JRC SSbD framework [4], defines the term 'by-design' in 3 levels: i) *Molecular design*: this is the design of new chemicals and materials based on the atomic level description of the molecular system. This type of design effectively delivers new substances, whose properties may, in principle, be tuned to be safe(r) and (more) sustainable. ii) *Process design*: this is the design of new or improved processes to produce chemicals and materials. Process design does not change the intrinsic properties (e.g. hazard properties) of the chemical or material, but it can make the production of the substance safer and more sustainable (e.g. more energy or resource efficient production process, minimising the use of hazardous substances in the process). The process design includes upstream steps, such as the selection of the feedstock. iii) *Product design*: this is the design of the product in which the chemical/material might be used with a specific function that will eventually be used by industrial workers, professionals or consumers.

The development of a new chemical/material is often brought on through an innovation process that can be structured in stage-gate approach. The process development can be monitored using the Technology Readiness Level (TRL) and at each stage quantitative and qualitative new information may be available for the assessment.

A new understating of safety: The safety concept is related to the absence of unacceptable risk for humans and the environment by avoiding the use of hazardous chemicals [4]. In the CSS, the ambitions towards a toxic-free environment and protection against the most harmful chemicals are evident. An important development is the extension of the generic approach to risk management to ensure that chemicals that cause cancers, gene mutations, affect the reproductive or the endocrine system, or are persistent and bioaccumulative, are not present in consumer products. This generic approach will be extended to other harmful chemicals including those affecting the immune, neurological or respiratory systems and chemicals toxic to specific organs [1]. The scope of this CSS is also to protect vulnerable groups which typically include pregnant and nursing women, the unborn, infants and children, the elderly people as well as workers and residents subject to high and/or long term chemical exposure [1].

A SSRbD integrated approach was developed and applied to polymeric materials in three case studies by integrating several approaches [4, 6, 9, 18, 19].

## 2.2 Testing the SSRbD integrated approach in various case

### studies

The first case study examines a new recyclable bio-sourced polyurethane (PU) for window frames in the building sector. The second case study examines a fire-resistant, intrinsically recyclable epoxy-vitrimer materials for composites to be used as train bodies in the transport sector. The third case study examines recyclable MultiNanoLayered (MNL) films with reduced compatibilizer concentrations in the food packaging sector. In this study, the SSRbD integrated approach is presented using the three case studies as demonstrators. The focus of this study is on the identification of the safety and sustainability hotspots and the development of SSRbD strategies. SSRbD strategies include for instance the use of bio-based sources instead of fossil-based, recycled material content, the use of easily-recyclable materials (e.g. vitrimerization), the use of safer (non-toxic) chemicals, additivation (e.g. covalently bound fire retardants, optimized content of compatibilizers), optimization of production processes with regards to energy and time, more energy efficient transport, simplified formulations for easy recycling, more durable products, and more efficient sorting, decontamination and recycling processes.

### 2.2.1 Supportive Interdisciplinary Case Study Groups

Internal professional multi-disciplinary co-creation sessions were held using tools such as menti and co-creation guidelines [20-22].

A series of internal workshops were organized during monthly meetings to brainstorm on how to operationalize the proposed SSbD framework from the EC to polymeric material specific SSRbD in a co-creation process involving consortium participants involved in the case studies, risk assessment, toxicology, eco-design and sustainable development. The SSRbD strategy and methodology was developed through several co-creation sessions with the SURPASS consortia [17]. An important consideration is that SURPASS is developing and implementing this strategy at the same time, and a first draft description is provided. The SSRbD strategy integrates innovation/functionality with safety and sustainability in an iterative process.

The content in Tables 1, 3 and 5 was developed with bi-weekly meetings with the case studies. Here, information for the tables was gathered and the SSRbD strategies were defined and optimized.

An internal interdisciplinary group was assigned to each case study encompassing SURPASS<fnref n="1" /> consortium partners with at least one partner from hazard, release and exposure, health and environmental life cycle impact and Life cycle costing. Additional teams for sustainability and qualitative scoring were also developed. The case study interdisciplinary group have monthly technical meetings to co-create strategies and provide the necessary data needed for risk and sustainability assessment.

## 2.3 Development of Guidance to facilitate safety and sustainability assessment

A guidance was developed for identifying polymer material relevant information needs for the dimensions of safety,

Accepted Manuscript

This article is protected by copyright. All rights reserved.

<footnote n="1">¹ https://www.surpass-project.eu/approach-and-methodology</footnote>
sustainability, and economic across the various life stages of polymeric materials, product and process through the integration of several approaches [10, 19, 23-27] and in co-creation with the SURPASS consortium.

# 3. Results and Discussion

## 3.1 Development of the SSRbD integrative approach

A SSRbD integrative approach was developed (Figure 1) consisting of three steps: i) the identification of criticality, toxicity, environmental, social, circularity, functionality and economic impacts from a life cycle thinking perspective; ii) the development of SSRbD strategies; and iii) verification of Safe, Sustainable, and Recyclable by Design strategies to ensure they lead to safer, more sustainable and more circular alternatives (Figure 1).

The SSRbD was applied to polymeric materials in three case studies. The first case study examines a new recyclable bio-sourced polyurethane (PU) for window frames in the building sector. The second case study examines a fire-resistant, intrinsically recyclable epoxy-vitrimer materials for composites to be used as train bodies in the transport sector. The third case

study examines recyclable MultiNanoLayered (MNL) films with reduced compatibilizer concentrations in the food packaging sector. In this study, the SSRbD integrated approach is presented using the three case studies as demonstrators. The focus of this study is on the identification of the safety and sustainability hotspots and the development of SSRbD strategies. SSRbD strategies include for instance the use of bio-based sources instead of fossil-based, recycled material content, the use of easily-recyclable materials (e.g. vitrimerization), the use of safer (non-toxic) chemicals, additivation (e.g. covalently bound fire retardants, optimized content of compatibilizers), optimization of production processes with regards to energy and time, more energy efficient transport, simplified formulations for easy recycling, more durable products, and more efficient sorting, decontamination and recycling processes.

The focus of this study is the first two steps of the SSRbD approach. For each of the case studies, the biggest safety & sustainability challenges were identified, along with the development of SSRbD strategies. The strategies identified in step two are currently under development to assess the technical feasibility, prior to the assessments of safety and sustainability improvements in step three.

<figure><img src="image_18.png" /><figcaption>Figure 1. SSRbD approach for the translation of the JRC SSbD framework to practical operationalization</figcaption></figure>

For the development of SSRbD strategies (analogous to the (re)design phase of the JRC framework), important characterisation parameters for polymeric materials were considered such as, functionality challenges. The implementation of SSRbD strategies leads to the development of a global practical approach to link the use of SSRbD strategies

and the assessment phase. Thus, the SSRbD practical approach will follow an iterative process that considers the Technology Readiness Level (TRL), integrating a life-cycle vision and covering the steps of the JRC SSbD framework assessments. In addition to the JRC reports mentioned above, the global practical approach developed also considers the CEN 1325 (Value Management, Value Analysis, Functional Analysis vocabulary) [28] and ISO 15686-5 standards (Buildings and constructed assets - Service life planning - Part 5: Life-cycle costing) [29]. Figure 2 shows how to link the SSRbD strategies and the assessment phase.
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<figure><img src="image_20.png" /><figcaption>Figure 2. SSRbD global practical approach developed in SURPASS to link SSRbD strategies and the assessment phase</figcaption></figure>

The first step (red and blue) of the approach defines the function in a life cycle perspective (functional unit). Recyclability is a technical function always included. The second step (yellow) defines performance criteria for technical solutions. The next step is the core of the approach with the Technical Design phase. To evaluate the SSRbD alternatives, the tiered approach is performed. The assessment stage follows the JRC SSbD framework plus the performance function assessment. Parallel assessments are preferred in contrast to sequential ones to allow iterative improvements. This choice is based on lessons learned from safe by design activities conducted in several projects [30-35]. The life cycle sustainability is then assessed against relevant defined aspects. If the whole process evaluation is successful (orange arrow), the product TRL design increases. If not, hotspots and leverage opportunities are identified (green arrow). SSRbD alternatives are then implemented and a new loop is performed. If no hotspots are identified, either performance criteria are reassessed, or the product development is stopped. If the product reaches the final TRL level, a blue arrow points at the SSRbD product obtained. The initial step is to identify value chain safety and sustainability challenges using 'big picture' and hotspot analysis.

The characterisation of polymeric materials should include: i) Polymer class: classification of polymers based on properties (e.g. thermoplastics or thermosets); ii) Polymer type: a specific sort of polymer within a polymer class (e.g. Polyethylene terephthalate, PET or Polypropylene, PP); iii) Grade and purity: a specific structure and molecular mass within a polymer type and purity; iv) Additives: substances added to the polymer to

improve its properties (e.g. pigment or flame retardant); v) Blends: combination of polymers (e.g. thermoplastic-thermoplastic blend); vi) Production residues: substances that do not deliberately remain in the material (e.g. catalyst or monomer); vii) Non-intentionally added substances (NIAS): substances that have not been deliberately added to the material or unplanned new substances resulting from contact to other materials (e.g. due to degradation substances that leach into the material) [19].

## 3.2 Case study descriptions

### 3.2.1 Building sector, Case Study CS#1: New recyclable-by-design bio-sourced polyurethane (PU) to replace PVC (polyvinyl chloride) as insulating material for window frames

Polyurethane (PU) foams are the best and affordable isolation materials present on the market [36]. PU foams have the potential to replace polyvinyl chloride (PVC) in some building applications, such as the insulating windows frames. The vitrimer acts like a catalysts that together with a temperature constraint can modify the behaviour of PU (Reformable Thermoset). This method avoids the energy-intensive chemical recycling to return to the monomer.

#### 3.2.1.1 Functionality

The expected functional properties for a PU window frame can be described as follows: i) Mechanical properties; ii) Thermal properties; and iii) non toxic product reaction to fire and controlled fumes released. More details on the functionality parameters are presented in Table 1.
<table><caption>Table 1 Functionality: Technical specifications for the development of recyclable bio-based window in the context of the Buildings Case of Study</caption><tr><td rowspan="4">Insulation properties</td><td>Thermal performance of windows, doors and shutters (ISO 10077-1:2017) — Calculation of thermal transmittance — Part 1: General</td><td>Thermal transmittance window 1040x1040mm = 1.4 W/m2K<br/>Thermal transmittance window 1040x1040mm = 1.3 W/m2K</td></tr><tr><td>Thermal transmittance (EN ISO 10077-2:2017 Thermal performance of windows, doors and shutters — Calculation of thermal transmittance — Part 2: Numerical method for frames.)</td><td>Thermal transmittance of frames/profiles (EN ISO 10077-2:2017) = 0,81 W/(m2K)</td></tr><tr><td>Air permeability (EN 1026:2017 windows and doors: air permeability)</td><td>Global classification: Class 3<br/>Classification standard: EN 12207:2017</td></tr><tr><td>Water tightness (EN 1027:2017. Windows and doors: Water tightness)</td><td>Global classification: Class 8A<br/>Classification standard: EN 12208:2000</td></tr><tr><td rowspan="4">Mechanical properties</td><td>Resistance to wind load (EN 12211:2017. Windows and doors. Resistance to wind load)</td><td>Global classification: Class C5<br/>Classification standard: EN 12210:2017</td></tr><tr><td>Resistance to static torsion EN 14609:2004 ERRATUM: 2010. Windows. Determination of resistance to static torsion</td><td>Global classification: 350 N CLASS 4<br/>Standard: EN 13115: 2001 Section 4</td></tr><tr><td>Shore A, Shore D hardness test: Standards ISO 48-4/DIN ISO 7619/DIN EN ISO 868/NF EN ISO 868/ASTM D 2240/JISK 6253</td><td>Shore D surface = 69<br/>Shore D – 3 mm from surface = 39<br/>Shore D core = 38</td></tr><tr><td>Bend strength: 3 pt bend test, deflection 4 mm<br/>Each profile has been bended 3 times with a time interval of 10 mins</td><td>Sample: profile INDRESMAT 4mm<br/>Machine extension at maximum load = 4.5mm<br/>Load at maximum extension = 139.5 N</td></tr></table>
<figure><img src="image_21.png" /></figure>

### 3.2.1.2 Material and Product re-design

**Current situation:** fossil-based window frames with complex formulation using toxic chlorinated flame retardant.

**Safer solution:** Bio-based polyurethane (PU) including halogen-free flame retardant.

The window products as developed are as solid as the wooden frames so they do not need metal reinforcement, as for PVC. Besides, these PU foams can be partially bio-based (currently <5% w/w bio-based content and a target of more than 75% w/w for the polyol phase by the end of the project). It has proven an extremely high insulating degree, with a heat transmittance more than 2 times lower than that of PVC (CE marking tests results). Its inherent properties allow some hazardous additives to be removed from the formulation, for example organo-halogen fire-retardant additives (as used in PVC) that can be efficiently replaced by innocuous mineral nitro-phosphate salts.

### 3.2.1.3 Process and Manufacturing re-design

**Current situation:** low recycling rate through mechanical or chemical methods. Solid polyurethane waste generated during window assembly and production.

**Safer and sustainable solution:** recyclable PU with enhanced vitrimer properties and prevention from using fresh resin.

The chemistry of PU makes recycling difficult as it cannot be melt-reprocessed like a thermoplastic. The current solution consists in micronizing unused PU and using it as a filler in new formulations, which allows recycling percentages to be no more than 50%, and in most cases degrading performance. An emerging alternative is chemical depolymerization [37], but with higher cost and energy demands. Today, less than 30% of thermoset PU is effectively recycled (the remaining is landfilled or incinerated).

### 3.2.1.4 Use and End-of-life

**Current situation:** unavailability of infrastructure for PU recycling purposes. There is a lack of safety in current vitrimization catalytic system.

**Safer and sustainable solution:** Safer vitrimization process adapted to new PU formulated matrix resulting in zero waste approach.

Material ageing is investigated through comprehensive accelerated weathering tests, assessing impacts on volatile organic compound (VOC) emissions and mechanical properties. At this stage, a maximum of 5% micronised scrap from the PU process is used to reprocess window frames. The use of vitrimer chemistry will be developed to increase the recyclability of PU and enable the up-cycling to create bio-sourced PU resins with enhanced vitrimer properties to replace PVC for window frames – with similar insulating properties, and able to achieve a higher

number of recycling loops.

An overview of the baseline generation is provided in Table 2 with the SSRbD strategies in Figure 3.
<table><caption>Table 2 Baseline Generation: Identification of safety and sustainability issues/hotspot for the Building sector Case Study</caption><thead><tr><th rowspan="2"></th><th colspan="4">Life cycle stage</th></tr><tr><th>Raw material and resources</th><th>Processing and manufacturing</th><th>Use</th><th>End-of-life</th></tr></thead><tbody><tr><th>Environmental impact</th><td>Polyamines are toxic for aquatic organisms and accidental release need to be considered.<br>Impregnation solvents (can be alcohols) during the vitirmerization process that have an impact as VOC + are flammable and ocular irritants<br>Integration of catalysts (IAS) in the polymer can increase the production of NIAS + release catalyst</td><td>Solid polyurethane residues (powder, chips) during window assembly<br>Compression moulding is done at high temperatures and actual situation needs to be considered<br>Use of recycled input, recycling process more complex than existing manufacturing process will need more qualified workers, manipulation of chemicals (even non-toxic) can lead to a disapproval of the process</td><td>Rigid polyurethane foams will, when ignited, burn rapidly and produce intense heat, dense smoke and gases which are irritating, flammable and/or toxic.<br>Polyurethanes form carbon monoxide, hydrogen cyanide and other toxic products on decomposition and combustion.<br>Solid polyurethane residues (chips) during window assembly</td><td></td></tr><tr><th>Social impact</th><td>Bio-based components (bio-polyols needed in INDRESMAT formulation): potential land use competition (feedstock)</td><td>Isocyanate extension and synthesis of poly(oxime-urethane) require more steps and more high-quality job positions.</td><td></td><td></td></tr><tr><th>Health-safety impact</th><td>Catalysts are organic or acid bases, they are classified as corrosive and can be irritant for lungs when used as powders.<br>Isocyanate, which is a main component in PU synthesis, needs to be used by specially trained employees due to its effect on human health<br><a href="https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32020R1149">https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32020R1149</a><br>A prominent example of PU vitrimer chemistry uses toxic catalysts, for example dibutyltin dilaurate, a tin-based catalyst</td><td>Window assembly tools can be dangerous to handle, sanding of the window frames could release fine dust particles which can harm the respiratory tract, solvent based paints (for windows)<br>Compression molding: considerations due to the high temperatures used (burning) and potential toxic vapours generation<br>Grinding (fine powders possibly affect the airway), impregnation (chemicals, solvent, temperature for drying solvents), extrusion (mechanical hazard, high temperature (160-200°C))</td><td>Isocyanates are toxic and it compulsory that &lt;1ppm of isocyanate group are unreacted in the final product.<br>Integration of catalysts (IAS) in the polymer can increase the production of NIAS + release catalyst</td><td></td></tr><tr><th>Economic impact</th><td>Bio-based components are not produced at large scale as much as fossil-based materials, therefore they could be more expensive<br>Fossil-based components depend directly on rising transport cost which is related to rising energy price due to Russia-Ukraine war<br>Poly(oxime-urethane) strategy requires more expensive materials than traditional PU and PVC</td><td>Energy consumption is expected to be higher than with the use of usual manufacturing process (grinding, impregnation and extrusion/foaming vs molding/foaming), a compromise between energy consumption and toxicity/flammability of solvents will be done for impregnation step</td><td>Polyurethane products require larger investment from the end user than commodities: raw materials price volatility due to oligopoly nature of polyurethane market</td><td></td></tr></tbody></table>
<figure><img src="image_22.png" /><figcaption>Figure 3. Mapping of the SSRbD Approach applied to the Building Case of Study (FR, flame retardant; PU, polyurethane)</figcaption></figure>
### 3.2.2 Transport sector, Case Study CS#2: Fire resistant, intrinsically recyclable epoxy-vitrimer materials for sustainable composites to replace metal for train body

In recent decades, the interest in the use of composite materials for structural applications for the transport sector has been increasing, mostly because composites are much lighter materials than some metal [38-40]. Currently, in the railway sector, composites are mainly used for interior parts and secondary structures. It is still of great interest to expand the application of these lightweight materials as alternatives to metals, which would allow a significant reduction in vehicle weight and, thus, energy consumption.

#### 3.2.2.1 Functionality

The functionality properties such as: i) Fire resistance avoiding toxic halogenated additives; ii) non-toxic fumes released during burning; iii) mechanical properties; iv) fixed hardener to support recyclability were considered. In addition to these functionalities, the production process of the composite is energy efficient (instead of the metal used in current railway). More details on the functionality parameters are presented in Table 3.

<figure><img src="image_23.png" /></figure>
<table><caption>Table 3 Functionality. Technical specifications for the fire-resistant recyclable epoxy vitrimer in the context of the Transport sector
Case Study</caption><thead><tr><th></th><th>Name</th><th>Fire resistant recyclable epoxy vitrimer for composites</th><th></th></tr></thead><tbody><tr><td></td><td>Activity Sector</td><td>Railway</td><td></td></tr><tr><td rowspan="3">Processing properties</td><td>initial viscosity (mPa·s) at working temperature and 10s-1</td><td>200-320</td><td rowspan="3">ISO 3219</td></tr><tr><td rowspan="2">Gel time at specific temperature (min)</td><td>infusion (60°C, 10s-1): 160 min up to 1 Pa·s<sup>1</sup></td></tr><tr><td>RTM (60-80°C, 1 Hz) &lt;60 (time when G'=G'')<sup>1</sup></td></tr><tr><td rowspan="4">Mechanical properties (Final Product)</td><td>Glass Temperature (°C)</td><td>&gt; 110</td><td>ISO 11357-2 (DSC)<br>ISO 6721-5 (DMA)</td></tr><tr><td>Tensile modulus (MPa)</td><td>2860-3350</td><td>ISO 527-2</td></tr><tr><td>Tensile Strength at Break (MPa)</td><td>&gt; 45</td><td>ISO 527-2</td></tr><tr><td>Flexural Strength (MPa)</td><td>&gt; 70</td><td>ISO 178</td></tr><tr><td rowspan="4">Flame resistance (Final Product)</td><td>Hazard level</td><td>HL2<sup>2</sup></td><td>EN 45545-2</td></tr><tr><td>MARHE (kW/m2)</td><td>max. 90</td><td>EN 45545-2<br>ISO 5660-1</td></tr><tr><td>Ds max. (dimensionless)</td><td>max. 600</td><td>EN 45545-2<br>ISO 5659-2</td></tr><tr><td>CITG (dimensionless)</td><td>max.1.8</td><td>EN 45545-2<br>ISO 5659-2</td></tr></tbody></table>

<footnote n="1">¹ The values shown are for small amounts of pure resin/hardener mix. In composite structures the gel time can differ significantly from the given values depending on the fibre content and the laminate thickness</footnote>

<footnote n="2">² Hazard levels are used for material fire safety requirement classifications</footnote>
#### 3.2.2.2. Material and Product re-design

Current situation: the use of metal and non-recyclable epoxy matrix which contains fibers and harmful flame retardants.

Safe and sustainable solution: Replacement of toxic flame retardant with halogen-free flame retardant and the use of a recyclable epoxy matrix and fiber.

The application of composite materials in rolling stock (primary structures) shall meet specific fire, smoke, and toxicity (FST) requirements, which are set by EN45545 [41], to ensure human and environmental safety.

The improved fire resistance comes from the use of flame retardants (FR) in composite materials. The current trend is to replace halogen-based flame retardants, especially bromine, with halogen-free flame retardants, which are less toxic and more environmentally friendly [36, 42]. The most common strategies to obtain flame retardant properties in halogen-free epoxy resin formulations are based on the use of inorganic flame retardants such as aluminum hydroxide (ATH), ammonium polyphosphate (APP), various organophosphorus compounds, etc. [42-44].

Glass or carbon fibre reinforcements for composites have good flame-retardant properties, and therefore it is mainly the resin that needs to be improved in terms of fire resistance.

Recently, some thermoset composite materials (i.e. once cured they cannot be re-mixed) that meet the requirements of EN45545 have been developed. However, these novel composite materials are not sustainable at the end of their useful life, as they are not intrinsically recyclable, and often end up landfilled or incinerated.

#### 3.2.2.3. Process and Manufacturing re-design

Current situation: The current manufacturing process is energy intensive with low input.

Sustainable solution: Infusion manufacturing process with medium energy consumption and high output.

A sustainable epoxy vitrimer system [45] which is easy to synthesize from readily available starting materials in a scalable manner and exhibits rapid high-temperature stress relaxation (vitrimer behaviour) without the need for a catalyst, making the material recyclable, reprocessable and repairable due to the

reversible bonds presented in the epoxy vitrimer system.

#### 3.2.2.4. Use and End-of-life

##### Final product re-design

Current situation: Heavy metal structure, or conventional non-recyclable composite material with flame retardants.

Safe and sustainable solution: A lightweight, halogen-free flame retardant which is recyclable due to structural composite part of railway.

To anticipate the growing replacement of metal by non-recyclable composite for structures, this case study, targets the transport sector with the objective of developing epoxy vitrimers that: i) meet all the requirements of the railway FST; ii) achieve the required mechanical performance; iii) fulfil the needs of the manufacturing process; iv) contribute to human and environmental safety through the use of non-harmful flame retardants and are intrinsically recyclable at the end of their life.

##### End-of-life

Current situation: high energy recycling of the metal and likely landfilling or incineration of non-recycling composite part.

Sustainable solution: Open loop recycling for additional valuable applications.

The rapid stress relaxation behaviour observed in the composites will allow the final product, and the waste generated during production as well, to be recycled through two different routes (mechanical and chemical route) in the product end-of-life phase. Thus, recycled parts will be generated, by simple mechanical recycling (grinding and thermoforming), and the epoxy matrix, fibres and flame retardants will be recovered and used for additional applications.

An overview of the baseline generation is provided in Table 4 with the SSRbD strategies in Figure 4.
<table><caption>Table 4 Baseline Generation: Identification of safety and sustainability issues/hotspot-Transport sector Case Study</caption><thead><tr><th rowspan="2">Baseline Generation: Identification of safety and sustainability issues/hotspot</th><th colspan="4">Life cycle stage</th></tr><tr><th>Raw material and resources</th><th>Processing and manufacturing</th><th>Use (product)</th><th>End-of-life (product)</th></tr></thead><tbody><tr><td>Environmental impact</td><td><strong>The epoxy resin</strong> (derived from the condensation reaction between epichlorohydrin and bisphenol-A) is fossil feedstock (from petroleum). At uncured stage, can give off fumes when it is applied or heated, and can also leach chemicals into the ground and water.<br/><strong>Di-amine hardener</strong> is made from petroleum products. No environmental impact identified for the time being (it is not classified in REACH). The synthesis process of both, leaves a large CO<sub>2</sub> footprint.</td><td><strong>Epoxy resin</strong>, at uncured stage, can give off fumes when it is applied or heated, and can also leach chemicals into the ground and water, contributing to land and water pollution</td><td><strong>The composite manufacturing by Prepreg process</strong>: medium-low throughput process</td><td>epoxy-based composites at the end of their life are burned or stored in landfills. The burning of these materials contributes to significant energy consumption as well as releasing harmful gases such as CO<sub>2</sub>, further accentuating the greenhouse effect.<br/>On the other hand, the storage of these materials in landfills occupies and pollutes natural areas.</td></tr><tr><td>Health-safety impact</td><td></td><td><strong>Epoxy resins</strong> give off fumes when it is applied or heated. These fumes can be harmful to the people who work with epoxy resin.</td><td><strong>Cured Epoxy resin</strong>: The epoxy resin once reacted with the curing agent, the final product is not harmful as it does not off-gas during its life cycle.</td><td></td></tr><tr><td>Social impact</td><td></td><td><strong>Halogen fire retardant additives (toxic)</strong></td><td><strong>Use of Halogen additives</strong> during processing manufacturing and life-cycle: hazardous health impact of halogenated compounds, particularly on the endocrine system of people exposed to this product (workers and civilians).</td><td></td></tr><tr><td>Economic impact</td><td></td><td>these flame retardant additives are based on fossil raw materials, which are exhaustible, and many of them are not present in Europe.<br/>Flame retardants and hardener are not produced at large scale, therefore they could be more expensive and insufficient</td><td></td><td>Major investment in incineration and landfill plants for disposal/minimisation of waste material</td></tr></tbody></table>
<figure><img src="image_24.png" /></figure>

<figure><img src="image_25.png" /><figcaption>Figure 4 Mapping of the SSRbD Approach applied to the Transport Case of Study</figcaption></figure>
### 3.2.3 Packaging sector, Case Study CS#3: Recyclable MultiNanoLayered (MNL) films to replace multi-layer films for packaging with reduced concentrations of compatibilizers.

Multilayer plastic films are widely used as packaging for food protection and preservation. This is due to their unique barrier properties, protection can be provided directly by preventing goods from contamination and indirectly by extending its shelf life [46].

The Multilayer films are commonly composed by multiple high performance layers, each one having their own useful function. Regardless their design, the outer layer provides sealability, printability and resistance against abrasion. Meanwhile, the inner layer provides, among others, oxygen barrier properties. The most common materials used for the external layers are polyolefins, with low-density polyethylene (LDPE) being the most prominent one, followed by polypropylene (PP), high-density polyethylene (HDPE), and polyethylene terephthalate (PET). With regards to the barrier properties, PA (polyamide), EVOH (Ethylene and Vinyl Alcohol copolymer), are widely used. Uncertainty about the impact in a recycling stream, unsuitable current designs and the absence of sorting and dedicated recycling concepts for such multilayers often prevent their recycling in an economically and environmentally sustainable way.

In multilayer film designs, such as five-layered films, the central layer is often delimited by two adhesive layers that enable adhesion to both the outer and inner layers. This structure is common in barrier films containing PA or EVOH, as these polymers exhibit poor adhesion to the primary structure. Therefore, copolymers, acting as tie-layers, are used to improve adhesion between the barrier and external layers [47]. The selection of compatibilizers in multilayer films is essential for optimizing performance, as they ensure proper adhesion between layers, which is critical for applications like food packaging. However, these tie layers also influence the overall recyclability of the films, adding cost and requiring careful consideration of their compatibility with existing recycling streams. The goal is to optimize their proportion to balance strong layer adhesion and desirable properties, such as oxygen permeability, while minimizing resource use and enhancing sustainability.

Multi-nanolayer (MNL) polymer based films, produced using a specific coextrusion technology, involve combining multiple extruders through a multichannel-layered feedblock to create films with up to 1,000 layers. Polymer streams are combined into parallel layers before exiting to form a film, sheet, or annular die. This nano-structuring process allows the production of films with good barrier, mechanical and optical properties, while reducing the need for compatibilizing agents, which helps lower costs and improves the recyclability of the final product through fine pre-dispersion.

MNL coextrusion is a continuous process the combination of one or more materials into films with several thousands alternating nanometric layers. The tortuous path created by this layering enhances gas barrier performances.

#### 3.2.3.1 Functionality

The functionality properties include: i) Sealability, printability and resistance against abrasion; ii) Oxygen barrier; iii) Shelf-life; and iv) Sealing strength. More details on the functionality parameters are presented in Table 5.

<figure><img src="image_26.png" /></figure>
<table><caption>Table 5 Functionality. Technical specifications for the design of Multi-nanolayers films in the context of the Packaging Case of Study (LLDPE- Polyolefins as low-density polyethylene)</caption><thead><tr><th></th><th>Name</th><th>Multilayer Film</th></tr></thead><tbody><tr><td rowspan="2">Final Product (General information)</td><td>Activity Sector</td><td>Food Packaging</td></tr><tr><td>Product Lifetime</td><td>Shelf life multilayer film up to 2 years – shelf for product packed can be up to 6 months depending on product</td></tr><tr><td rowspan="6">General Characteristic of Final Product</td><td>Width (mm) + tolerance</td><td>422 (0+1)</td></tr><tr><td>Thickness (µm) + tolerance</td><td>200 (±10%) – other options possible in range 50 to 300 µm</td></tr><tr><td>Food contact layer</td><td>LLDPE (External layer)</td></tr><tr><td>Shrinkage (%)</td><td>MD/TD = &lt;10%</td></tr><tr><td>Indicative values (directly after thermoforming)</td><td>Additional shrinkage (after 24h package); MD/TD = &lt; 5%</td></tr><tr><td>Thermoforming range (indicative) (°C)</td><td>90°C to 110°C</td></tr><tr><td rowspan="7">Mechanical properties (Final Product)</td><td>Young's Modulus (N/mm²) MD</td><td>350 (method based on ASTM D882)</td></tr><tr><td>Young's Modulus (N/mm²) TD</td><td>400 (method based on ASTM D882)</td></tr><tr><td>Tensile Strength at Break (N) MD</td><td>&gt;65 (method based on ASTM D882)</td></tr><tr><td>Tensile Strength at Break (N) TD</td><td>&gt;65 (method based on ASTM D882)</td></tr><tr><td>Elongation at Break (%) MD</td><td>&gt;400 (method based on ASTM D882)</td></tr><tr><td>Elongation at Break (%) TD</td><td>&gt;400 (method based on ASTM D882)</td></tr><tr><td>Seal Strength (N/m)</td><td>&gt;1200 (method based on ASTM F88)</td></tr></tbody></table>

MD is the direction that a material unwinds as it's being fed into a press, tunnel, or any other device. Transverse direction or TD is the direction that is 90 degrees to the machine direction

ASTM D882 is a standard test method for determining the tensile properties of thin plastic films with a thickness of less than 1.0 mm (0.04 in) and is of great importance in the film packaging industry, both for quality control and research and development.

ASTM F88 measures the peel strength of packaging in one of two peel configurations under normal ambient temperatures
### 3.2.3.2 Material and Product re-design

**Current situation:** External layers of Polyolefins as low-density polyethylene (LDPE) with EVOH (Ethylene and Vinyl Alcohol copolymer) for barrier properties.

**Safe and sustainable solutions:** PE/EVOH and PE/PA blends are developed to form base multilayer films without multipliers. The MNL polymer based films result in lower contents of Polyethylene grafted with maleic anhydride (PE-g-MA).

The Multilayer films are commonly composed by multiple high performance layers, each one having their own useful function. Regardless their design, the outer layer provides sealability, printability and resistance against abrasion. Meanwhile, the inner layer provides oxygen barrier properties. The MNL polymer based films result in lower contents of PE-G-ma and potentially lower amounts of barrier materials for the same performance.

### 3.2.3.3 Process and Manufacturing re-design

**Current situation:** Multi-layer extrusion where risk assessment is necessary at the workplace to ensure there is minimal PE-g-MA exposure. PE-g-MA, handled as a pure solid form, is irritating to the eyes, the respiratory system and the skin.

**Safe and sustainable solution:** multi-nanolayer coextrusion process with low levels of PE-g-MA. Playing with the # of layers and thickness to reduce the % of PE-g-MA and potentially reduce the amount of barrier material.

Multi-nanolayer films coextrusion is developed by first establishing combinations of PE/EVOH and PE/PA blends to form base multilayer films without multipliers. This step is needed to test the homogeneity of the layers and their interfacial adherence, as well as for optimizing the viscosity difference between the co-extruded polymers. Blends will then be formulated with different concentrations of compatibilizers applying the multi-nanolayer coextrusion technology, using diverse multiplying elements. The objective is to obtain multi-nanolayer films with up to 1024 layers. Therefore, with the best formulations, the influence of the nanolayering parameters (number of layers, thickness, and composition of the layers) on the barrier and mechanical properties of the final product will be investigated.

### 3.2.3.4 Use and End-of-life

**Current situation:** There is a complex waste collection and sorting system needing decontamination for closed loop recycling.

**Safe and sustainable solution:** Safer and less complex bends resulting in better sorting, increased recyclability and reduction of landfill waste; all supporting a closed material loop recycling.

An overview of the baseline generation is provided in Table 6 with the SSRbD strategies in Figure 5.

<table><caption>Table 6 Baseline Generation: Identification of safety and sustainability issues/hotspot-Packaging sector Case Study</caption><thead><tr><th rowspan="2"></th><th colspan="4">Life cycle stage</th></tr><tr><th>Raw material and resources</th><th>Processing and manufacturing</th><th>Use</th><th>End-of-life</th></tr></thead><tbody><tr><th>Environmental impact</th><td>Climate Change: Emission of Greenhouse Gases<br/>Fossil feedstock<br/>Water use environmental indicator (PEF)</td><td>Energy use - fossil fuels (MJ)<br/>Water use environmental indicator (PEF)<br/>Waste generation (kg/kg)<br/>Release of monomers and Volatile Organic Compounds (VOC)</td><td>Single Use product<br/>Consumer awareness on environmental impacts</td><td>Complex Waste Collection and sorting system<br/>Recycling efficiency/recovery rate (%)<br/>Amount of waste to landfill (kg/kg)<br/>Critical extract from decontamination processes</td></tr><tr><th>Social impact</th><td>Child labour</td><td>Assessment of accident at work</td><td colspan="2">Awareness about the overconsumption<br/>Pollution in third world countries (export of critical residues)</td></tr><tr><th>Health-safety impact</th><td>Absence of most harmful substances according to CSS (EC, 2020) and SVHC of REACH Art. 57 (EU, 2006)</td><td>Risk assessment at the workplace</td><td>Likelihood of human exposure and potential route (inhalation, dermal, ingestion)<br/>Environmental hazard: Specific Environmental Release Categories (SpERCs)</td><td>Potential presence of contaminants or hazardous substances in product waste<br/>Existing recycling and treatment of contaminated packaging</td></tr><tr><th>Economic impact</th><td>Economic crisis impact on fossil prices</td><td>Economic crisis impact on fossil prices-> Higher raw material's prices-> Higher final product prices</td><td></td><td>Value of recycled materials vs. undesired effects limiting the value of the PE waste stream</td></tr></tbody></table>
<figure><img src="image_27.png" /><figcaption>Figure 5 Mapping of the SSRbD Approach applied to the Packaging Case of Study (LLDPE- Polyolefins as low-density polyethylene; EVOH - Ethylene and Vinyl Alcohol copolymer; PA- Polyamide; Pe-g-Ma - Polyethylene grafted with maleic anhydride; IAS, Intentionally Added Substances; NIAS, Not Intentionally Added Substances)</figcaption></figure>
### 3.3 Reflections and Guidance development for the safety and sustainability assessment

The developed SSRbD approach is line with the EC JRC framework in the (re)design phase [4] and the scoping analysis in the EC JRC methodological guidance [6]. The scoping analysis consists of three steps: i) the system definition, ii) the (re)design definition, and iii) the engagement with the actors along the life cycle. At the end of the scoping analysis, the safety and sustainability assessments need to be performed in an iterative way. The first step of the SSRbD approach ('big picture' and hotspot analysis) aligns with the 'the system definition', while the development of SSRbD strategies (second step) aligns with the '(re)design definition' steps of the scoping analysis in the EC JRC methodological guidance. In addition, the supportive interdisciplinary case study groups address the third step of the scoping analysis by supporting engagement with actors along the life cycle.

A key lesson learned in the development of the SSRbD approach is the importance of co-creating in an inter-disciplinary team. This is in line with learning-by-doing work related to SSbD building blocks and roadmap [48, 49]. Also, the explicit inclusion of recyclability as a key performance criterion in SSRbD solutions highlights the need for a thorough evaluation of system complexity versus recycling performance. For example, the use of added substances like compatibilizers in multilayers or vitrimerization catalysts for PU introduces additional considerations that may not arise in a more linear SSbD approach, where such substances would typically be minimized. This comprehensive analysis ensures the selection of safe and sustainable “enabling” materials that support both performance and recyclability.

In order to provide guidance on how to start the safety and sustainability assessment, a guidance for identifying polymer material relevant information needs for the dimensions of safety, sustainability, and economic across the various life stages of polymeric materials, product and process was developed (Table 7).
<figure><img src="image_28.png" /><figcaption>Table 7. Guidance for identifying polymer material relevant information needs for the dimensions of safety, sustainability, and economic across the various life stages of polymeric materials, product and process (integrated from [10, 19, 23-27] and in co-creation with SURPASS consortium)</figcaption></figure>

<table><thead><tr><th></th><th></th></tr></thead><tbody><tr><td><strong>Safety</strong></td><td></td></tr><tr><td>Hazard characterization/assessment Human toxicity:</td><td><ul><li>Are the raw materials used classified as hazardous or persistent? (Avoid the use of hazardous or persistent substances, as they may circulate or hamper the re-use potential of materials or products).</li><li>Are there any hazardous properties identified in (e.g. REACH, CLP)? Is there any Ecotoxicological (potential accumulation/persistency) information (e.g. basic information on potential ecotoxicity, read across data) in scientific literature? How are the chemical components labelled? Are there any carcinogenic, mutagenic and reprotoxic (CMRs), endocrine disruptor (ED) or substance of very high concern (SVHC)?</li><li>Are there any legislative restrictions associated with polymeric material?</li><li>Characterisation of polymeric material:<ul><li>Polymer class</li><li>Polymer type</li><li>Grade</li><li>Additives</li><li>Blends</li><li>Production residues</li><li>Non-intentionally added substances (NIAS)</li></ul></li><li>Is the polymeric material biopersistent?</li><li>What is the toxicity of the polymeric material (if in vitro and in vivo toxicity test are performed)</li><li>For transformation and recycling process: Are there any restricted or toxic process contaminant?</li><li>Which transformations of the polymeric material can be expected throughout the life cycle?</li><li>Is it possible to use read across or grouping of relevant forms to fill remaining data gaps for risk assessment?</li></ul></td></tr><tr><td>Environment toxicity</td><td><ul><li>Ecotoxicity: Are there any legislative restrictions REACH, CLP associated with polymeric material?</li><li>Ecotoxicological (potential accumulation/persistency) information (e.g. basic information on potential ecotoxicity, read across data) in scientific literature.</li><li>Ecotoxicological information (specific information on potential acute & chronic ecotoxicity, potential bioaccumulation).</li><li>In vivo acute & chronic ecotoxicity test on algae, crustacean and fish Ecotoxicological information: Growth inhibition in aquatic plants, In vitro tests using relevant cell lines: cytotoxicity assays for metabolic activity, membrane integrity, lysosomal function. Biopersistence and biodurability.</li></ul></td></tr><tr><td>Exposure characterization / assessment</td><td><ul><li>What is the intended formulation and the potential exposure route and population?</li><li>Which transformations of the polymeric material can be expected throughout the life cycle?</li><li>Which types of exposure and release scenarios can be expected? Qualitative description of intended material production process, product production and after use.</li><li>Occupational exposure measurement (measures workers exposure concentrations).</li><li>What are relevant exposure reduction measures? Assessment of relevant exposure reduction measures and their efficiency.</li><li>What is the outcome of the risk assessment of the polymeric material for the relevant exposed populations throughout the life cycle of the product?</li><li>What are the uncertainties in this assessment? Are there still important data gaps (e.g. advice for further testing)?</li><li>Does occupational exposure increase due to the upscaled process? Update of relevant exposure reduction measures in occupational setting in response to up scaling.</li><li>Is the quality of the production process sufficient?</li><li>Mobility/Public health exposure considerations?</li></ul></td></tr><tr><td><strong>Environment</strong></td><td></td></tr><tr><td>Raw Materials and resources</td><td><ul><li>Are critical raw materials used?</li><li>Does the process of extracting the raw materials require high energy, water, or land consumption and/or have an environmental impact?</li><li>Can recycled material be used to replace raw materials Manufacturing</li><li>Does the manufacturing process require high energy, water, or land consumption and/or have an environmental impact?</li><li>Can the manufacturing process be energy and water efficient?</li></ul></td></tr><tr><td>Is there a high amount of waste in the process of manufacturing?</td><td><ul><li>Is the waste generated during manufacturing recyclable or reusable?</li><li>Does the emissions or waste generated during manufacturing contain persistent or hazardous substances (CLP)?</li><li>In the processes of manufacturing, what volume of solvents or water are used?</li></ul></td></tr><tr><td>Production,</td><td><ul><li>Does the production process require high energy, water, or land consumption and/or have an environmental impact?</li></ul></td></tr></tbody></table>
- Can the production process be energy and water efficient? Opportunity of relocation of manufacturing where energy and water efficiency is improved: less transport, better energy carbon footprint?

- Is there a high amount of waste in the process of production?

- Is the waste generated during production recyclable or reusable?

- Does the emissions or waste generated during production contain persistent or hazardous substances (CLP)?

- In the processes of production, what volume of solvents or water are used?

Transport

- Does the transportation process require high energy, water, or land consumption and/or have an environmental impact?

- Is there a high amount of waste in the process of transportation?

- Is the waste generated during transportation recyclable or reusable?

- Does the emissions or waste generated during transportation contain persistent or hazardous substances (CLP)?

Use

- Does the use require high energy, water, or land consumption and/or have an environmental impact?

- Is there a high amount of waste in the process of manufacturing?

- Is the waste generated during use recyclable or reusable?

- Does the emissions or waste generated during use contain persistent or hazardous substances (CLP)?

- During use, what volume of solvents or water are used?

End-of life (Recyclability and reusability)

- Can the raw material in the application context be recycled, re-used or recovered?

- Is the recycling process efficient? (i.e. is volume and quality of recycling product sufficient for a circular economy?)

- Is there an efficient system in place to recycle the products? Or is there a concept or plan to recycle the material/recover the individual materials?

- Does the process of recycling require high amounts of energy, water, or land consumption and/or have an impact on global warming potential (emission of greenhouse gases)?

- Is it possible to re-use (most of) the materials in the same or another function?

- Are different components used that are integrated, which might make recycling technically difficult?

- Is the application of the material or product durable e.g. long-term functionality, or reparable? (Durable indicates that there is long-term functionality)

Other aspects

- Protection & restore biodiversity and ecosystems services.

- Other relevant indicators that might be considered abiotic depletion, acidification, eutrophication, ozone layer depletion, photochemical oxidation potential, particulate matter (respiratory inorganics), ionizing radiation (effects on human health)

Economic

- Is there expected profitability (Social and economic value, net present value, financial profit, payback period)?

- What are life cycle cost & externalities?

- Does polymeric material and product meet market-related criteria (Meeting stakeholder expectations and product performance)?

- Is there transparency and information about polymeric material and product?

- What is the product cost (purchase cost, production cost)?

- Is there value chain collaboration to ensure lifecycle thinking approach?

- Are circular business models used?

- Is essentiality information available?

Social

- Is customer protection (health & safety of local community's living conditions, product safety, impact on consumer health) considered?

- Is Occupational health & safety Health & Safety (occupational health risks, safety management a work, management of worker's individual health, (see safety - human) considered?
Human and Labor rights/Basic rights & needs (fair wages, appropriate working hours, no forced labor, human trafficking and slavery, no discrimination, harassment prevention, social/employer security and benefits, access to basic needs, respect for human rights and dignity).

- Supply chain responsibility, (community engagement, local employment, safe and healthy living conditions, transparency and responsible communication, consumer product experience, end-of-life responsibility)

- What is the contribution to economic and technology development (education, job creation, joint research)?

- Skills & knowledge (skills, knowledge and employability, promotion of skills and knowledge for local community and consumers)
<figure><img src="image_29.png" /></figure>

## 4. Conclusions

A qualitative SSRbD integrated approach was developed consisting of: 1) the identification of functionality, criticality, toxicity, environmental, social, circularity/recyclability, and economic impacts in a life cycle thinking perspective; 2) the development of SSRbD strategies; and 3) verification of SSRbD strategies to ensure they lead to safer and more sustainable alternatives. These first 2 steps were applied to three case studies in the building, transport and packaging sectors. The third step would include a more quantitative or semiquantitative approach. A guidance was also developed on how to start the safety and sustainability assessment (Step 3), for identifying polymer material relevant information needs for the dimensions of safety, sustainability, and economic across the various life stages of polymeric materials, product and process was developed.

The developed approach is novel in comparison to other published work [6, 8, 10, 13] in i) the inclusion of quantitative functionality product parameters (Tables 1, 3, and 5), ii) the application of SSRbD at the product level (instead of at the material or chemical level) in the plastic sector and value chain, and iii) in the inclusion of re(design) strategies at the material and product level, at the process and manufacturing level and at the use and end-of-life level with extra focus in recyclability and circularity. The biggest challenge was optimizing the necessary product functionality while applying the SSRbD strategies. The global practical approach (Figure 2) where functionality is central supports the ‘fail-early, fail-cheap’ industrial principle for innovation [13] and competitiveness by providing strategies to close the innovation gap [50]. From a broader scientific perspective, the field of innovation needs to be closer to the fields of safety and sustainability (environmental, social, economic). In this way, the knowledge generated in safety and sustainability is applied in industrial innovation practices. An efficient science-policy-industry interface is needed to bridge this knowledge transfer gap [51].

Finally, in terms of internal organization, an interdisciplinary group for each case study encompassing partners from hazard, release and exposure, health and environmental impact and life cycle costing was developed to actively support the operationalization of the SSRbD approach. In this respect, new business models are needed which embed SSbD principles in innovation projects [52]. Innovation managers play an important role in bringing SSbD to practical applicability and training is needed for them to embed SSbD into their daily practices [52].

## Funding Information

SURPASS (Safe-, sUstable- and Recyclable-by design Polymeric systems: A guidance towardS next generation of plasticS) received funding from the European Union's Horizon Europe research and innovation programme under grant agreement No 101057901.

## Acknowledgement

SURPASS would like to acknowledge the case study lead partners INDRESMAT, CIDETEC, and IPC.

## Primary Data

No

## Conflict of Interest

The authors declare no conflict of interest.

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