Further background information: Revised draft risk profile
Published 9 March 2026
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This publication is available at https://www.gov.uk/government/publications/call-for-comments-on-a-revised-draft-risk-profile-of-a-substance-proposed-as-a-persistent-organic-pollutant-pop-2026/further-background-information-revised-draft-risk-profile
The UK is a party to the UN Stockholm Convention on persistent organic pollutants (POPs), which are substances that persist in the environment, accumulate in living organisms and pose a risk to our health and the environment. They can be transported by air, water or migratory species across international borders, reaching regions where they have never been produced or used.
Substances listed in the convention are generally prohibited from production, marketing or use, unless specific exemptions apply or acceptable purposes for continued use have been agreed.
There is a process for parties to propose a substance for listing if they have gathered evidence that suggests it may be a POP. The POPs Review Committee (POPRC), the technical scientific committee of the Stockholm Convention, then considers and further develops the evidence that the substance demonstrates POP characteristics.
If there is evidence that a substance demonstrates POP characteristics, the POPRC then considers the social and economic impacts of a ban or restriction of this substance and makes recommendations to the Stockholm Convention Conference of Parties, which is held every 2 years.
1. Revised risk profile (covering Annex E of the Stockholm Convention)
At the 20th meeting of The Stockholm Convention’s POPs Review Committee, the Committee evaluated the proposal by Switzerland to list polyhalogenated dibenzo-p-dioxins and dibenzofurans in Annex C to the Stockholm Convention. The Committee concluded that these compounds meet the screening criteria specified in Annex D to the Convention (decision POPRC-20/4).
At its 21st meeting in 2025, the Committee decided to defer its decision on the draft risk profile to its 22nd meeting (21 to 25 September 2026).
A draft revised risk profile further elaborates on, and evaluates, the information submitted in the original proposal. It covers the following substances:
- polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs)
- mixed polybrominated/chlorinated dibenzo-p-dioxins and dibenzofurans (PBCDD/Fs), excluding polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs)
A risk profile sets out the evidence that these substances meet the criteria for a POP. We are interested in any information you have to support, expand on or challenge the evidence provided.
Subsequent stages of POPRC evaluation consider social and economic information relating to nominated substances, so you may also wish to provide information on the following topics related to the use of these substances:
- risk management measures
- alternatives
- costs
- benefits
2. Polyhalogenated dibenzo-p-dioxins and dibenzofurans
Polyhalogenated dibenzo-p-dioxins and dibenzofurans (PXDD/Fs) are a large group of chemicals containing 1 to 8 halogen atoms. The scope of the proposal covers polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and mixed polybrominated/chlorinated dibenzofurans (PBCDD/Fs). Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), though belonging to the group PXDD/Fs, are not included in the scope of the proposal as they are already listed in Annex C of the Stockholm Convention.
There is currently no known intentional manufacture of PXDD/Fs, they are unintentionally generated through thermal processes involving brominated flame retardants (BFRs) including the uncontrolled burning of waste containing BFRs such as polybrominated diphenyl ethers (PBDEs). In addition, PXDD/Fs have been identified in emissions from metallurgical industries, thermal disposal of e-waste and mechanochemical non-combustion technologies being used to treat contaminated soil.
Elevated levels of PXDD/Fs have been found in some children’s toys and consumer products sampled from around the world. There are links to elevated levels of PXDD/Fs in locally produced food, such as eggs, in areas with high levels of uncontrolled burning and dismantling or recycling of e-waste containing brominated or chlorinated flame retardants.
It has been suggested that PXDD/Fs have the potential to damage human health and their high level of persistence in humans could lead to bioaccumulation.