Defra has made the Control of Mercury (Enforcement) (Amendment) Regulations 2025 (SI 2025/1189), approved by both Houses under the affirmative procedure. Signed on 12 November 2025 and in force from 3 December 2025, the instrument updates the 2017 enforcement regime for mercury with respect to Northern Ireland. It records special regard to section 46 of the UK Internal Market Act 2020.
The instrument amends the Control of Mercury (Enforcement) Regulations 2017 to recognise new EU restrictions that apply in Northern Ireland via the Windsor Framework. It designates additional provisions as “relevant” for enforcement and adjusts customs assistance so the authorities can police revised import and export rules on dental amalgam.
The underlying EU change is Regulation (EU) 2024/1849, which phases out dental amalgam across the EU. It prohibits use from 1 January 2025 except where a dentist judges it strictly necessary, bans export from 1 January 2025, and bans import and manufacturing from 1 July 2026 (subject to narrow medical‑need exceptions).
For Northern Ireland, the European Commission has issued a Notice under the Windsor Framework confirming that amalgam may continue to be used for dental treatment of UK‑resident patients and imported into Northern Ireland for that purpose until 31 December 2034, or an earlier date if agreed under the Minamata Convention. Use is limited to registered practitioners and is subject to conditions on monitoring and proportionality.
Customs and enforcement are tightened. Regulation 33 of the 2017 Regulations is updated so HMRC officers can assist with enforcement of the new export prohibition on dental amalgam applying to Northern Ireland from 1 January 2025, and-after 31 December 2034-the import prohibition when the transitional arrangements end.
Schedule 1 to the 2017 Regulations is revised so that the new EU measures-covering use, export, import and related obligations-are treated as “relevant provisions” for compliance and sanctioning. This ensures the existing UK enforcement toolkit (investigations, notices and penalties) can be applied to breaches in Northern Ireland.
In practice, dentists in Northern Ireland may continue using amalgam on UK‑resident patients during the transition. Treatment must be carried out by a registered dentist or registered dental care professional, as defined in section 53(1) of the Dentists Act 1984, and providers should retain evidence of patient residency and clinical justification where applicable.
Supply chains should note that manufacturing of amalgam in Northern Ireland is prohibited from 1 July 2026. Import is permitted to serve UK‑resident patients but must remain commensurate with actual use; from 1 July 2026, importers must follow the specific customs formalities referenced in the EU rules for “specific medical needs”. Resale into the EU is not permitted, and authorities will penalise non‑compliance.
Movements are treated differently depending on destination. Export of amalgam from Northern Ireland to outside the United Kingdom is prohibited from 1 January 2025. Movements within the UK are domestic and unaffected by the EU export ban, but EU suppliers cannot export amalgam to Northern Ireland after that date because EU exports to third countries are barred.
Key dates for planning are now fixed. The SI takes effect on 3 December 2025. EU‑level export prohibitions apply from 1 January 2025; EU import and manufacturing bans begin on 1 July 2026; Northern Ireland’s permitted use and import ends on 31 December 2034, after which the import prohibition will also be enforceable in Northern Ireland.
These amendments apply with respect to Northern Ireland only and do not alter policy for Great Britain. However, the Commission will monitor progress against the 2034 end‑date and the UK authorities must demonstrate steady reduction in use and robust enforcement, including sanctions for misuse or diversion. Practices and suppliers should align procurement, records and patient protocols accordingly.