The treaty seeks to prohibit or restrict the production and manufacture of the most harmful chemicals and Parties are required to reduce or eliminate the release of POPs from waste. To date, there have been 31 substances listed under the Convention.
The Convention is implemented through domestic legislation in each country. The European Union (EU) are also a Party to the Convention and they have recently reviewed and updated their EU POPs Regulations to reduce waste limits for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD) and short chain chlorinated paraffins SCCPs, as well as for polychlorinated dibenzodioxins/polychlorinated dibenzofurans (PCDD/PCDF) impurities in fly ash from waste incinerators.
The Department for Environment, Food and Rural Affairs (DEFRA) are consulting on proposed changes to Retained EU Persistent Organic Pollutants Regulations to add newly listed POPs and to amend legislation for existing POPs. The consultation is taking place following a review of the EU evidence base (most notably on waste limits), some of which the UK contributed to as a Member State, and in response to scientific or technical progress. DEFRA are seeking views on whether to update waste concentration limits for several POPs, to remove specific exemptions, to update unintentional trace contaminant (UTC) limits or exemptions, to add new Toxic Equivalency Factor (TEF) values for dioxin-like polychlorinated biphenyls (PCBs) and to amend maximum concentration limits for several POPs.
The consultation is targeted towards manufacturing and waste industries, as these are most likely to be impacted by the changes. Companies that will be affected by the changes are invited to provide evidence to DEFRA to support or dispute the proposed changes. Such information may include, but not be limited to, costs incurred to businesses, information on concentration of POPs in articles and waste and any cases of potential non-compliance with the proposed changes. DEFRA are also calling for evidence to fill regulatory data gaps for POPs in the UK, including for setting unintentional trace contaminant (UTC) limits for a number of POPs.
Interested stakeholders should review the proposals against their business needs, and review what impacts, if any, the updated legislation would have on their business before responding to the consultation.
What are DEFRA Proposing?
Based on evidence assessments undertaken by the Environment Agency, DEFRA are proposing new waste limits for perfluorooctanoic acid (PFOA), dicofol, pentachlorophenol (PCP) and perfluorohexane sulfonate (PFHxS) as well as reduced waste limits for SCCPs, PBDEs and HBCDD. Many of these proposals seek to bring domestic legislation in line with proposals that have been agreed at the international level, for example a limit of 50 mg/kg for Dicofol and 100 mg/kg for PCP (agreed at Stockholm COP-10 in 2022). The consultation also shows that DEFRA are also anticipating waste limits of 1 mg/kg for salts of PFOA and PFHxS and 40 mg/kg for PFOA and PFHxS related compounds to be agreed at the upcoming COP-11. An additional limit of 0.025 mg/kg for PFOA in Aqueous Film Forming Foams (AFFF) is proposed. Multiple waste streams were sampled in determining the waste limits, including clothing and shoes, carpets, firefighting foams and non-woven personal and protective equipment (PPE) waste. Concentrations of PFOA above the threshold limits were not found in any waste stream, except for AFFF where PFOA was found in significant quantities (1.8 mg/kg – 7.3 mg/kg), dropping to as little as 0.025 mg/kg for stockpiled foams. It is estimated that setting a waste limit of 0.025 mg/kg for PFOA in AFFF would prevent the release of up to 1800 tonnes of stockpiled waste AFFF into the environment in total. Detailed information on all sampled waste streams is found in the footnote below.
Short chain chlorinated paraffins are used as plasticisers and flame retardants in rubber, paints, adhesives and plastics. International waste limits have provisionally been set at 1500 mg/kg or 100 mg/kg. As in the EU, DEFRA are proposing to set the limit at 1500 mg/kg, a reduction from the current domestic limit of 10,000 mg/kg. The reduced waste limit would capture a small number of products across various waste streams, including polyvinyl chloride (PVC) products, flooring, and automotive shredder residue. Certain applications, including waste electronic and electrical equipment (WEEE) and non-WEEE cables, will not be affected by the waste limit (e.g., non-WEEE cables contain on average SCCP concentrations between 500-1200 mg/kg), whereas rubber waste from end-of-life conveyor belts used for underground mining will exceed the 1500 mg/kg limit and should be collected separately.
PBDEs are commercial flame retardants with widespread use in plastics, polymers, textiles, adhesives and coatings, amongst other things. Their listing under the Stockholm Convention covers the tetra, penta, hexa, hepta, and deca congeners with current waste limits set at 1000 mg/kg as a sum of all PBDEs. Under the proposed changes, this would be reduced to 350 mg/kg, dropping to 200 mg/kg five years after entry into force. It is anticipated the new international limit will be set at 500 mg/kg, dropping to 350 mg/kg after five years, mirroring the changes brought in by the EU. Limits of 500 mg/kg or 100 mg/kg have been agreed internationally for HBCDD and DEFRA are proposing to reduce domestic waste limits from 10,000 mg/kg to 500 mg/kg.
In 2022, DEFRA also conducted a review of UK exemptions that are permitted under the Stockholm Convention. Based on the results, DEFRA are proposing to remove the following exemptions from UK regulation:
- Perfluorooctane sulfonic acid (PFOS) used as a mist suppressant for non-decorative hard chromium (VI) plating in closed loop systems;
- SCCPs in substances, mixtures or articles containing SCCPs in concentrations <1% or <0.15% by weight;
- PFOA in the production of pharmaceutical products, in membranes (for gas/water filters), industrial sealants and in waste heat exchanger equipment;
- DecaBDE in the manufacture of aircrafts and aircraft spare parts;
If agreed, the above substances would no longer be permitted for use in these applications in the UK.
The consultation also contains proposals to reduce the Toxic Equivalency Factor for dioxins, furans and dioxin-like PCBs from 0.015 mg TEQ/kg to 0.005 mg TEQ/kg and to update regulations to designated hazardous waste landfilling of ‘fly ash from untreated wood’ and ‘soil and stones other than those mentioned in 17 05 03’.
What Does This Mean for the UK?
If the proposed changes are written into legislation, what will this mean for UK businesses and regulators, and what does it show about environmental ambition in the UK? Some changes will lead to an increase in the amount of POPs waste that requires destroying or irreversible transformation, such as the reduced PFOA limit that will capture AFFF stockpiles, or the SCCP limits that will impact various waste streams. These measures will inevitably have cost implications for UK industry but will mitigate some adverse effects caused to humans and the environment through exposure to POPs. The removal of specific exemptions for four substances shows that UK businesses have made progress against the objectives of the Stockholm Convention, allowing for exemptions to expire as viable alternatives are identified for these substances. Similarly, a reduction or removal of Unintentional Trace Contaminant limits for various POPs shows that trends are heading in the right direction.
There are also instances where more could be done. Almost all of the waste streams sampled for PFOA would be unaffected by the new limits; despite articles in these waste streams containing low concentrations of PFOA, the accumulative effects of leaching into the environment and/or reincorporation into the product life cycle should not be underestimated. Similarly, where UTC limits have been reduced for the use of PFOA in polytetrafluoroethylene (PTFE) micropowders, certain derogations have been granted which exempt UK businesses. In practice, governments must evaluate the environmental benefits of ambitious measures against the impact on UK businesses and the technical limitations in current waste processes. DEFRA could enforce more stringent waste limits, but does the infrastructure exist in the UK to meaningfully implement them? Does the technology exist to identify, separate and incinerate all wastes containing POPs?
It appears the overarching purpose of the consultation is to amend outdated legislation to reflect developments at the international level and many of the proposed changes mirror those adopted in the EU. The consultation does however show some divergence from the EU, for example by proposing lower waste limits for PBDEs, or by removing a UTC exemption for PFOA in transported isolated intermediates. Evidently, UK regulators have sought to understand the true landscape of POPs in the UK and are striving to ensure domestic POPs regulations reflect the needs and nature of UK businesses.
Katie Hobson joined the Logika Group from the International Chemicals team in DEFRA, where she covered the Stockholm Convention on POPs and the Beyond 2020 Framework for the sound management of chemicals and waste. The Group has a wealth of experience in chemicals policy in the UK and internationally. If you or your business would benefit from our support in responding to DEFRA’s consultation, or similar issues, please contact us at firstname.lastname@example.org.
 Formally ‘Persistent Organic Pollutants (Amendment) (EU Exit) Regulations’
 European Waste Catalogue code 17 05 03 covers ‘soils and stones containing hazardous substances’.
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