Defra has made the Control of Mercury (Enforcement) (Amendment) Regulations 2025 (SI 2025/1189), an affirmative instrument approved by both Houses and signed on 12 November 2025. It enters into force on 3 December 2025. The SI amends the 2017 enforcement framework to implement, for Northern Ireland, EU Regulation 2024/1849 on mercury as it applies under the Windsor Framework. The legal powers cited are section 8C and Schedule 7 of the European Union (Withdrawal) Act 2018, with special regard to section 46 of the United Kingdom Internal Market Act 2020.
The instrument inserts new references into the Control of Mercury (Enforcement) Regulations 2017 so UK authorities can enforce EU restrictions on dental amalgam in Northern Ireland. In particular, it adds Article 10(7) of the EU Mercury Regulation (export and, later, import prohibitions) and lists new EU measures as “relevant provisions” for the purposes of enforcement action.
The underlying EU law phases out dental amalgam across the Union. From 1 January 2025, use is prohibited except where a practitioner judges it strictly necessary; from the same date, export is banned; from 1 July 2026, import and manufacturing are prohibited, subject only to narrow medical-need derogations.
Northern Ireland is treated differently under arrangements acknowledged by the European Commission. Until 31 December 2034, Article 10(2a) on the use ban and the import limb of Article 10(7) are to be read as not applying where a registered dentist or registered dental care professional treats a person residing in the United Kingdom in Northern Ireland. Manufacturing remains prohibited from 1 July 2026 and export from Northern Ireland to outside the UK is banned from 1 January 2025.
Customs enforcement is updated. Regulation 33 of the 2017 Regulations is amended so that customs officials may seize and detain material suspected of breaching the new export ban from 1 January 2025, and, after 31 December 2034, the import ban for dental amalgam into Northern Ireland. This ensures Border Force and HMRC can assist the competent authorities where consignments fall foul of the EU prohibitions as read for Northern Ireland.
Schedule updates make the EU rules enforceable in practice. The SI lists as relevant: Article 10(2a) on use, Article 10(7) on export/import/manufacture, and Article 18(1a) which requires importers and manufacturers of dental amalgam to report volumes annually. These changes align domestic enforcement with the EU rulebook that applies in Northern Ireland via the Windsor Framework.
Additional conditions flow from the Commission’s Notice on applying Regulation 2024/1849 to the UK in respect of Northern Ireland. The Commission accepts continued use and import into Northern Ireland for UK‑resident patients until 31 December 2034, or an earlier phase‑out date agreed under the Minamata Convention, provided Northern Ireland prohibits export, ends manufacturing from July 2026, and keeps imports commensurate with use. Annual reporting to the Commission is required.
Movements of amalgam will tighten after July 2026. Imports into Northern Ireland from Great Britain or third countries must follow full customs formalities; for GB–NI movements, the Commission Notice notes dental amalgam will be treated as Category 1 goods under Annex IV to the Windsor Framework Decision. HMRC guidance on the Simplified Process for Internal Market Movements sets out the Category 1 concept and procedural expectations.
For dental practices in Northern Ireland, the effect is operational rather than theoretical. Amalgam may continue to be used only when the patient resides in the UK and the treatment is carried out by a registered dentist or registered dental care professional in Northern Ireland. Providers should be prepared to evidence residency and professional registration if asked by inspectors, given the SI’s enforcement basis and the Commission’s requirement for penalties where the conditions are breached.
For suppliers and importers, the reporting and proportionality tests matter. From 2026, importers must ensure consignments are consistent with actual dental use and, by 31 May each year, provide quantity data to the competent authority under Article 18(1a). The Northern Ireland authorities must then submit a yearly report to the Commission by 31 December, including usage metrics and actions taken to transition away from amalgam.
From 1 January 2035, the carve‑out falls away. The import prohibition in Article 10(7) will apply in Northern Ireland for dental amalgam, and the standard EU position on use takes effect, meaning any residual use would be limited to strictly necessary cases and constrained by the absence of new supply. Practices and suppliers should plan for a complete shift to mercury‑free alternatives ahead of that date.
The parliamentary record confirms the Government’s rationale: avoiding immediate capacity and cost pressures in Northern Ireland while maintaining the EU’s market and environmental protections. With the SI now made and commencement set for 3 December 2025, compliance work should focus on residency checks, stock management aligned to demand, and readiness for Category 1 procedures on GB–NI movements from mid‑2026.