Key messages: Hazardous flame retardants in materials entering waste streams (e.g. electronics waste) and legislation restricting or preventing recycling those materials could present a key barrier to EU circularity goals. There is a need to develop resource-efficient methods for identifying and separating waste containing hazardous flame retardants.

Environmental and health risks of flame retardants

Flame retardants (FRs) have been commonly added to plastics, textiles and electrical or electronic equipment to reduce flammability and improve product safety (UNEP, undated; NIEHS, undated). They may be released into the environment during product use; for example, during textile washing cycles. Common groups of FRs include brominated flame retardants (BFRs), such as hexabromocylodecane (HBCD) and polybrominated diphenyl ethers (PDBEs), chlorinated flame retardants and organophosphate flame retardants (OFRs) (NIEHS,  undated). In addition, a significant number of FRs on the market do not belong to a specific group.

There are concerns relating to the persistent, bioaccumulative and toxic (PBT) or very persistent and very bioaccumulative (vPvB) properties of brominated FRs (ECHA, 2023a). A number of brominated FRs are associated with adverse health effects including endocrine disruption, reproductive and developmental toxicity, neurotoxicity and cancer (NIEHS, undated; Chevrier et al., 2010; Herbstman et al., 2010; Greeson et al., 2020; Dong et al., 2021). The United Nations Environment Programme (UNEP) has highlighted that many FRs are of major concern due to their high toxicity and potential to be released from plastics.

Some brominated FRs are already restricted in the EU under the regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) and at international level, with several families of brominated flame retardants (e.g. PBDEs, HBB and HBCDD) listed as persistent organic pollutants (POPs) under international conventions (Stockholm and Rotterdam conventions). The European Chemicals Agency (ECHA) has also identified additional FRs as candidates for restriction in its regulatory strategy for flame retardants (ECHA, 2023b).

Flame retardants and plastics recycling

The EU has established ambitious targets for recycling plastics under its Plastics Strategy and Circular Economy Action Plan. The increasing rate of plastic recycling requires, as much as possible, identifying and minimising the presence of hazardous chemicals like hazardous FRs and their derivatives in recycled plastic goods on the European market (Stapleton et al., 2009; Herbstman et al., 2010; ARCADIS, 2017; Stapleton et al., 2011). For example, there have been rising concerns that recycled plastic containing hazardous FRs is being used to produce consumer goods (EC, 2019). One study investigating recycled plastic children’s products from 26 countries (including both EU and non-EU countries) found that 90% of samples contained OctaBDE or DecaBDE, with almost 50% containing HBCD (DiGangi et al., 2017). This study is however very limited in terms of the number of samples and types of products. Human biomonitoring has been used to evaluate exposure to hazardous substances, including several prioritised FRs. Recent studies from the HBM4EU project have investigated the exposure of children in Europe to these FRs. They observed high detection for DPHP and BDCIPP across nine countries (Van der Schyff et al., 2023).

Electrical and electronic equipment waste is recognised as one of the fastest-growing waste streams in the EU. While recycling rates vary among EU countries (European Environment Agency, n.d) currently less than 40% of Waste from Electrical and Electronic Equipment (WEEE) is recycled in the EU (European Parliament, 2020). This could be a particular sector of focus for increasing recycling rates. One study investigated 30 plastic items produced from recycled electronic waste purchased in the EU, and found that 25% contained hazardous FRs (Straková, 2018). For example, due to the illicit recycling of plastic from WEEE into food contact materials (FCMs), hazardous BFRs have been found in FCMs on the European market, which are not authorised for food contact (EC, 2019).

In the EU, legislation exists to limit or restrict the level of hazardous FRs in consumer materials, for example in electrical and electronic equipment (EEE), toys and FCMs. Complying with such requirements is a significant challenge for waste management, particularly recycling plastic materials already containing FRs. For example, all waste containing FRs listed under the Stockholm Convention above a specific limit value must be destroyed. Recycling such material is also prohibited. The presence of FRs in waste plastics therefore presents a significant barrier to recycling these materials, potentially hindering circular economy ambitions as well as posing a potential ongoing risk to human health.

Key challenges and knowledge gaps

There are a number of key challenges and knowledge gaps relating to the presence of hazardous substances such as toxic FRs in plastic waste (EC, 2019). In particular, there is a lack of comprehensive data on the presence and concentrations of toxic FRs in recycled plastics. The identification and analysis of FRs in recycled plastics is itself a challenge, as FRs form a large chemical group with diverse chemical structures. There is also a lack of data at the waste stage for FRs. In general, recyclers find it challenging to guarantee the exact composition of secondary material, which limits recycling.

Information on global flows of products produced from recycling materials is scarce. Gaining knowledge on the presence and concentrations of substances in plastics manufactured from recycled material is challenging, since the composition of the waste may be unknown. Intricate chemical analysis of such waste material is not always practical (Stenmarck Å. et al., 2017; EC, 2019) and there are currently limitations in both analytical and technical approaches. The lack of an effective screening method may hinder plastic recycling processes (Sharkey et al., 2020).

While a number of alternatives to the more hazardous halogenated and phosphorus-based flame retardants have been identified, only a limited number have been implemented: many are not desirable from an environmental and health perspective (KEMI, 2020). More knowledge is needed about which alternatives are preferable, to assist efforts in finding appropriate substitutes. The Safe and Sustainable by Design framework of the European Commission can support identifying such substitutes.

References and footnotes

ARCADIS, 2017, Identification and evaluation of data on flame retardants in consumer products — final report (https://www.europeanfiresafetyalliance.org/publications/identification-and-evaluation-of-data-on-flame-retardants-in-consumer-products/).   

Chevrier, J., et al., 2010, ‘Polybrominated diphenyl ether (PBDE) flame retardants and thyroid hormone during pregnancy’, Environmental health perspectives, 118(10), pp.1444-1449 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2957927/).

Council of the EU, 2023, ‘Waste shipments: Council and Parliament reach agreement on more efficient and updated rules’ (https://www.consilium.europa.eu/en/press/press-releases/2023/11/17/waste-shipments-council-and-parliament-reach-agreement-on-more-efficient-and-updated-rules/?utm_source=dsms-auto&utm_medium=email&utm_campaign=Waste+shipments:+Council+and+Parliament+reach+agreement+on+more+efficient+and+updated+rules) accessed 8 January 2024.

DiGangi, J., et al., 2017, POPS Recycling Contaminates Children’s Toys with Toxic Flame Retardants (https://ipen.org/sites/default/files/documents/toxic_toy_report_2017_update_v1_5-en.pdf).

Dong, L., et al., 2021, ‘New understanding of novel brominated flame retardants (NBFRs): Neuro (endocrine) toxicity’, Ecotoxicology and Environmental Safety, 208, p. 111570.

EC, 2019, A circular economy for plastics Insights from research and innovation to inform policy and funding decisions (https://op.europa.eu/en/publication-detail/-/publication/33251cf9-3b0b-11e9-8d04-01aa75ed71a1/language-en/format-PDF/source-87705298).

ECHA, 2023a, ECHA identifies certain brominated flame retardants as candidates for restriction (https://echa.europa.eu/-/echa-identifies-certain-brominated-flame-retardants-as-candidates-for-restriction).  

ECHA, 2023b, Regulatory strategy for flame retardants (https://echa.europa.eu/documents/10162/2082415/flame_retardants_strategy_en.pdf/9dd56b7e-4b62-e31b-712f-16cc51d0e724?t=1678871526283).

EEA, 2021, Plastics, the circular economy and Europe’s environment – a priority for action, EEA Report No 18/2030 (https://www.eea.europa.eu/publications/plastics-the-circular-economy-and/)

EEA, undated, ‘Waste recycling’ (https://www.eea.europa.eu/en/circularity/thematic-metrics/materialsandwaste/wasterecycling) accessed[AE1]  8 January 2024.

European Parliament, 2020, E-waste in the EU: facts and figures (infographic) (https://www.europarl.europa.eu/news/en/headlines/society/20201208STO93325/e-waste-in-the-eu-facts-and-figures-infographic#:~:text=E-waste%20recycling%20rate%20in%20the%20EU.%20Less%20than,Infographic%20showing%20e-waste%20recycling%20rates%20per%20EU%20country)

Greeson, K.W., et al., 2020, ‘Detrimental effects of flame retardant, PBB153, exposure on sperm and future generations’, Scientific Reports 10 (1), p. 8567.

Herbstman, J.B., et al., 2010, ‘Prenatal exposure to PBDEs and neurodevelopment’, Environmental health perspectives 118(5), pp.712-719 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866690/).   

KEMI, 2020, Kartläggning av alternativ till bromerade, klorerade och fosforinnehållande flamskyddsmedel i elektronik, PM 1/20 (https://www.kemi.se/publikationer/pm/2020/pm-1-20-kartlaggning-av-alternativ-till-bromerade-klorerade-och-fosforinnehallande-flamskyddsmedel-i-elektronik) accessed 8 January 2024.

NIEHS, undated, Flame Retardants (https://www.niehs.nih.gov/health/topics/agents/flame_retardants/index.cfm).

Sharkey, M., et al., 2020, ‘Phasing-out of legacy brominated flame retardants: The UNEP Stockholm Convention and other legislative action worldwide’, Environment International 144, p. 106041 (https://pubmed.ncbi.nlm.nih.gov/32822924/).

Stapleton, H.M., et al., 2009, ‘Detection of organophosphate flame retardants in furniture foam and US house dust’, Environmental science & technology 43(19), pp. 7490-7495.

Stapleton, H.M., et al., 2011, ‘Identification of flame retardants in polyurethane foam collected from baby products’, Environmental science & technology, 45(12), pp.5323-5331 (https://pubs.acs.org/doi/pdf/10.1021/es2007462). 

Straková, J., et al., 2018, Toxioixot Loophole – Recycling hazardous waste into new products (https://arnika.org/en/publications/toxic-loophole-recycling-hazardous-waste-into-new-products).

Stenmarck, Å., et al., 2017, Hazardous substances in plastics–ways to increase recycling, IVL Swedish Environmental Research Institute, Nordic Council of Ministers (https://www.ivl.se/download/18.34244ba71728fcb3f3fa26/1591705754132/C233.pdf).

UNEP, undated, ‘Flame Retardants’ (https://www.unep.org/explore-topics/chemicals-waste/what-we-do/persistent-organic-pollutants/flame-retardants).  

Van Der Schyff, V., et al., 2023, ‘Exposure to flame retardants in European children—Results from the HBM4EU aligned studies’ International journal of hygiene and environmental health 247, p. 114070 (https://research.vu.nl/en/publications/exposure-to-flame-retardants-in-european-children-results-from-th).