Defra has confirmed new enforcement rules for mercury that take effect in Northern Ireland on 3 December 2025, following the making of the Control of Mercury (Enforcement) (Amendment) Regulations 2025 on 12 November. The update equips customs to police an export ban on dental amalgam from Northern Ireland and aligns local practice with recent EU changes applying under the Windsor Framework.

In practice, the law locks in three milestones. First, exporting dental amalgam from Northern Ireland is prohibited. Second, manufacturing will be prohibited from 1 July 2026. Third, a tailored arrangement lets registered dental professionals in Northern Ireland continue to import and use amalgam to treat UK‑resident patients until 31 December 2034, after which the import ban applies. These measures implement Regulation (EU) 2024/1849 while giving Northern Ireland a longer runway to switch to mercury‑free fillings.

Why it matters is straightforward: mercury is a potent neurotoxin. The World Health Organization lists mercury among the top ten chemicals of major public‑health concern and warns that even small exposures can harm the developing brain, with unborn children at particular risk. Cutting intentional uses reduces a persistent pollutant that moves through air, water and the food chain.

The dental pathway is well understood. Mercury from fillings can enter the environment via crematoria emissions and improper waste handling; that’s why separators are already mandatory in dental surgeries under existing rules. In England alone, crematoria emitted roughly 310 kg of mercury to air in 2022, according to the Environment Agency’s official indicator. Proper capture and treatment cut releases at source.

Europe’s direction of travel is clear. Under the revised EU Mercury Regulation, using and exporting dental amalgam is banned from 1 January 2025, with import and manufacturing bans from 1 July 2026 save for strictly justified medical needs. The Northern Ireland update enforces those timelines locally while recognising healthcare realities.

Brussels has also set out how these rules apply in Northern Ireland without undermining the EU single market. The European Commission’s formal notice confirms the export prohibition from NI, a ban on manufacturing from 1 July 2026, and a time‑limited allowance to import and use amalgam for UK‑resident patients until the end of 2034 or an earlier date set by the Minamata Convention.

There is a wider river‑health angle. New analysis by Wildlife and Countryside Link and The Rivers Trust found that more than 98% of fish and mussels tested in English rivers and coastal waters exceed proposed EU safety levels for mercury, with over half above that threshold fivefold. While mercury has multiple sources, further reducing dental inputs is a practical step the UK can accelerate.

For dental teams, the message is planned transition, not sudden change. Expand training and procurement for mercury‑free materials, maintain and routinely audit amalgam separators, and use authorised waste collectors without exception-requirements already embedded in UK enforcement of the EU Mercury Regulation. Importers in Northern Ireland should also prepare to meet new reporting duties on amalgam volumes.

Crematoria operators have a clear role too. Government guidance under review proposes extending mercury‑abatement technology to all sites, with tighter monitoring of other pollutants. Installing full abatement and maintaining systems properly will deliver immediate health and environmental gains for nearby communities.

What to watch next: ministers told Parliament they are assessing future UK‑wide policy on dental amalgam ahead of November’s Minamata Convention talks. Northern Ireland’s 2034 back‑stop could be brought forward if a global phase‑out date is agreed-another reason for services and suppliers to plan now.