Northern Ireland will be allowed to keep importing and using dental amalgam for the treatment of UK residents until 31 December 2034, while exports from Northern Ireland are prohibited. The change takes effect on 3 December 2025 via the Control of Mercury (Enforcement) (Amendment) Regulations 2025, signed by Defra minister Emma Hardy on 12 November.

For readers across the North, this matters more than it first sounds. Many dental suppliers in Lancashire, Merseyside and Yorkshire ship to practices in Belfast, Derry and across the border counties; those orders will now sit inside a tighter enforcement regime shaped by the Windsor Framework rather than a blanket GB rulebook.

The statutory instrument updates the 2017 Control of Mercury enforcement rules so that customs officials can assist with policing import and export restrictions on dental amalgam in respect of Northern Ireland. It also lists the new EU mercury measures as relevant provisions for UK enforcement in Northern Ireland, reflecting the EU’s 2024/1849 amendment and the Commission Notice that explains how those rules apply under the Windsor Framework.

Crucially, the regulations create a time‑limited carve‑out in Northern Ireland. Until the end of 31 December 2034, the EU restriction on the use of dental amalgam does not apply when a registered dentist or registered dental care professional provides dental treatment in Northern Ireland to a person residing in the United Kingdom. Over the same period, the general EU prohibition on importing dental amalgam into Northern Ireland does not apply where the material is for that clinical use.

After that date, the position tightens. From 1 January 2035, the import prohibition will apply in Northern Ireland, and the use restriction will bite unless ministers or the EU change course. In the meantime, the export of dental amalgam from Northern Ireland is prohibited from the day these regulations come into force.

For suppliers on this side of the Irish Sea, the message is simple but important. Orders routed to Northern Ireland can continue where they are clearly for dental treatment of UK‑resident patients by registered professionals in Northern Ireland. Expect checks, with HMRC and Border Force able to assist enforcement, particularly on Irish Sea routes that many northern firms rely on, such as those through Liverpool and Heysham.

Defra’s note says no full impact assessment was prepared because the expected cost to business is de minimis. Even so, practices and wholesalers will want clear paperwork and frank conversations with carriers so consignments are not delayed for end‑use questions once the rules start on 3 December.

Legally, this sits on familiar foundations since Brexit. The powers come from the European Union (Withdrawal) Act 2018 and the instrument was approved by both Houses of Parliament. It implements the EU’s updated mercury regime in Northern Ireland under the Windsor Framework and acknowledges, as required, the UK Internal Market Act 2020 considerations about how rules affect trade within the UK.

Definitions are baked in to keep the scope narrow: registered dentist and registered dental care professional carry the meanings in the Dentists Act 1984. For everyone else in the North-procurement leads, practice managers and suppliers-the practical takeaway is to get compliant now, keep lines open with Northern Ireland customers, and plan for the longer switch due by the end of 2034.