The circular economy in electronics: How old casings are turned into new ones
Flame retardants, product design and recycled material quality as levers for plastic cycles in e-waste
Smartphones, laptops, headsets: hardly any other product group is replaced as quickly as electronics. Consequently, the mountain of end-of-life devices is growing, and with it the quantity of plastics they contain. Unlike copper or gold, these plastics are often regarded as a problematic fraction in recycling.
E-waste: a recyclable material with a problematic fraction
Globally, around 62 million tonnes of electronic waste were generated in 2022, an average of 7.8 kilograms per capita. Around 17 million tonnes of this was plastic. Only 22.3 per cent of the total volume of e-waste was verifiably collected and properly recycled, as shown by the ‘ ’ Global E-waste Monitor 2024. This figure relates to e-waste as a whole, not specifically to the plastics it contains. The UN organisations responsible for the report, ITU and UNITAR, expect this figure to rise to around 82 million tonnes by 2030.
Economically speaking, it is primarily metals that drive recycling: copper, aluminium and precious metals from printed circuit boards. However, after shredding, the plastics remain as a mixed fraction. Some of this is so contaminated that it cannot be recycled at all. And according to the EU research service CORDIS, around 400,000 tonnes of plastic from waste electrical and electronic equipment in Europe is considered too heavily contaminated and is incinerated. But why is this the case? What can be done about it? And, above all, what limitations are imposed by material composition and current regulatory requirements?
At a glance
- Flame retardants: Residual contaminants in old casings determine whether plastics can be recycled.
- Design: Separability and reparability determine what can be recovered later.
- Recyclates: Through targeted processing, recycled plastics find their way back into new appliances.
Why it is difficult to keep electronic plastics in the circular economy
The electronics sector faces a combination of challenges that is virtually unique to this industry:
- Short lifespan: Many devices are replaced after just a few years, often before they are faulty.
- Many small devices: Cables, chargers and headphones often end up in general waste or are left in a drawer.
- Variety of materials: Housings contain, amongst other things, ABS, HIPS, PC, PC/ABS and PP, as well as pigments, fillers and additives.
- Complex material composites: Plastics are often bonded to metals, circuit boards or batteries. In particular, bonding, potting, coatings and overmoulding make it difficult to recover materials by type.
Legacy issue: flame retardants
Because electrical appliances carry an electric current and generate heat, many plastic casings must be flame-retardant. For a long time, brominated flame retardants were frequently used for this purpose. It is not the entire group of substances that is banned, but rather certain compounds: Polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs), for example, have been severely restricted in new electrical appliances since July 2006 under the RoHS Directive; several PBDEs are also classified as persistent organic pollutants (POPs). Nevertheless, they are still present in the end-of-life equipment arriving for recycling today. This is a key problem for professionals in the recycling sector: if the PBDE content in the waste exceeds the limit values set by the EU POPs Regulation, conventional material recycling is not permitted. The pollutants must then be destroyed or irreversibly transformed in accordance with legal requirements. And these limit values for the total PBDE content are falling: from 500 milligrams per kilogram to 350 as of 30 December 2025, and to 200 from 30 December 2027 (Regulation (EU) 2022/2400). Reliably identifying and sorting out contaminated plastics is therefore becoming a key issue.
Mechanical recycling is the established method for well-sorted, uncontaminated plastic streams. Solvent-based processes offer a further option for recovering plastics from complex waste streams. They dissolve the plastic, separate out flame retardants and other contaminants, and recover the polymer. This is particularly useful when additives need to be specifically separated, but it presents its own technical, economic and energy-related challenges. In the EU project ‘ ’ (PLAST2bCLEANED), led by the Dutch research organisation TNO, around 9 kilograms of recycled material were produced on a pilot scale from 16 kilograms of contaminated ABS. The levels of hazardous substances were subsequently below the legal limits, and the material met, for example, the requirements for washing machine door frames. However, to achieve the necessary impact strength, it had to be blended with virgin material. The process is therefore not yet established on an industrial scale or economically viable. Similar approaches were pursued by the project ‘ ’ (CREAToR), coordinated by the Fraunhofer Society, including the use of supercritical CO₂ in a twin-screw extruder.
Design determines the next cycle
Whether plastics can be recovered from a device is determined as early as the development stage. Key factors are:
- Using screws instead of adhesives, so that the casing, battery and electronics can be cleanly separated
- A small number of compatible plastic grades rather than many different materials
- Clearly labelling plastic components and designing them so that the materials can be reliably identified and separated during the recycling process, including via sensor technology in automated sorting plants
Consequently, devices that can be easily dismantled are also easier to repair. This extends their useful life, and when the device has finally reached the end of its life, the plastics enter the recycling loop in a more sorted state. The Fairphone 6, from the Dutch manufacturer of the same name, illustrates just how far this approach can be taken. Twelve components can be replaced, including the battery, display and USB-C socket. The repair platform iFixit awarded it the top score of 10 out of 10.
High-quality recycled materials require formulation work
However, even cleanly sorted plastics from e-waste cannot simply be remelted and reprocessed. Depending on the material quality and the thermal and mechanical stresses encountered during processing, mechanical recycling can, for example, damage the rubber phase of ABS or reduce the molecular weight of polycarbonate. At the same time, depending on the application, the plastics used must meet high standards for heat resistance, impact strength and fire behaviour, such as specific classifications under UL 94. High-quality recycled materials are therefore not produced simply by melting them down, but through targeted processing, compounding with suitable additives such as stabilisers or impact modifiers, and, in some cases, the addition of virgin material (Plastics Engineering). Equally important are material testing and quality assurance, to ensure that recycled materials from fluctuating waste streams reliably achieve the required properties. This is precisely where the plastics industry brings its core competencies to bear: from sorting and separation technology, through compounding, to the selection of materials suitable for recycling in product development. Internal components such as brackets and covers provide a pragmatic starting point. Visible outer shells and screw caps, however, require more rigorous testing.
Case study: How does recycled material find its way into a headset?
Covestro demonstrates that recycled plastics also work in demanding electronic components. According to the manufacturer, the flame-retardant polycarbonate blend Bayblend FR3010 R75 consists of up to 75 per cent post-consumer recycled material and is used in the ear cups of the Jabra Evolve2 headset. For consumer electronics, the company also offers the polycarbonate Makrolon PCR, which contains 90 per cent post-consumer recycled material. According to the manufacturer, its carbon footprint is 70 per cent lower than that of comparable virgin fossil-based material. To ensure the recycled material is sufficiently heat-resistant, impact-resistant and fire-retardant, the selection and processing of the raw material are crucial.
Find out more about polycarbonates containing recycled content here!
Regulation is increasing the pressure
Legislators are also increasingly focusing on durability and the circular economy. From 20 June 2025, EU ecodesign requirements will apply to new smartphones, mobile phones and tablets coming onto the market: Essential spare parts must be available for at least seven years after a model is taken off the market, whilst operating system updates must be provided for at least five years thereafter. Added to this is the EU right to repair, which Member States were required to implement by 31 July 2026 and which has been in force since that date (European Consumer Centre).
The next step is also imminent: as things stand, the European Commission intends to present its proposal for a Circular Economy Act on 18 November 2026, after the deadline had already been postponed several times. Among other things, it is intended to revise the EU Waste Electrical and Electronic Equipment (WEEE) Directive and harmonise producer responsibility schemes (EUWID). Minimum recycled content targets are also under discussion (ERP). Nothing has been decided yet: the proposal will be followed by the legislative process in the Parliament and the Council. Should binding recycled content targets be introduced, this could significantly increase demand for qualified recycled materials from e-waste.
Key learnings
- Large material flow: Plastics account for a good quarter of e-waste, but so far only a small proportion has been recycled to a high standard.
- Sorting is key: Contaminants such as certain brominated flame retardants must be identified and separated.
- Design lays the foundation: Devices that can be dismantled and repaired, and which contain few types of plastic, make recycling easier.
- Recycled materials require expertise: High quality is achieved through formulation, not simply by remelting.
Conclusion: Recycling alone is not enough
Plastics from waste electrical and electronic equipment are therefore not merely a residual fraction, but a stream of recyclable materials with considerable potential. However, for this potential to be realised, several factors must work together: devices that can be repaired and dismantled, collection systems that also capture small waste appliances, sorting technology that reliably identifies contaminated materials, and recycled materials that, thanks to compounding and quality assurance, meet the requirements of the electronics industry. The planned EU regulations could accelerate this transformation.
For manufacturing, processing and recycling alike, this means that those who embed circularity in their design and choice of materials today will secure the raw materials of tomorrow.
Further articles in the series:
How can the circular economy succeed in different sectors? This series highlights the specific challenges and potential solutions facing various industries. Articles on packaging, automotive manufacturing and consumer goods have already been published. Further sectors will follow.
- Click here for the article on “The Circular Economy in Packaging”.
- Click here for the article on “The Circular Economy in Consumer Goods”.
- Click here for the article on “The circular economy in medical technology”.
- Click here for the article on “The circular economy in the construction sector”.
- Click here for the article on “The Circular Economy in the Automotive Industry”.
Author: Ann-Kathrin Ullrich | K-Mag
Ann-Kathrin Ullrich enjoys explaining how new ideas from research, technology and industry are changing everyday life. Alongside her work for EuroShop-Mag, she focuses on plastics and rubber in K-Mag: from new materials and processing methods through to testing technology and issues relating to the circular economy.
