UK REACH is the chemicals regulation that applies to substances manufactured in or imported into Great Britain (England, Scotland, Wales). It's administered by the HSE and the Environment Agency rather than ECHA. The obligations mirror EU REACH (registration, evaluation, authorisation, restriction) but operate under a separate UK candidate list, a separate authorisation list and a separate restrictions regime.

You're in scope if you're a GB-based manufacturer or importer of a substance at one tonne or more per year, or a downstream user placing a substance on the GB market for the first time. Distributors aren't registrants but carry duties to communicate hazard information up and down the supply chain.

EU-based suppliers selling into GB can't register directly. They sell through a GB-based importer who carries the registration obligation, or they appoint a GB-based Only Representative.

Substances grandfathered from EU REACH and those notified via DUIN are working toward full UK REACH registration on a phased timeline. The government has consulted on an Alternative Transitional Registration model (ATRm) that reduces the data requirements for substances already registered under EU REACH. Confirm the current statutory deadline for your tonnage band on the HSE website before submission.

The two regimes started identical and are slowly diverging. Key live divergence points include:

• Separate SVHC candidate lists. A substance can be added to one list and not the other.
• Separate authorisation decisions, with different sunset dates and review periods.
• Separate restriction proposals under Annex XVII equivalents.
• Different fee schedules and registration data requirements (under ATRm proposals).

Operationally this means you can't assume an EU REACH-compliant substance is UK REACH-compliant, and the gap will grow with each candidate list update.

Under the Windsor Framework, EU REACH continues to apply for substances placed on the Northern Ireland market. A substance moving GB to NI is treated as a movement onto the EU market for REACH purposes. This is the single most common source of confusion for UK supply chains and worth modelling explicitly in master data.

The pragmatic answer for most chemical and cosmetics businesses is to hold one substance master tagged against both regimes, with divergence points (different SVHC entries, different authorisations) surfaced as alerts. This is how Worldover handles it: one record per substance, two regulatory overlays, one source of truth for SDS, declarations and dossiers.

The government has confirmed an Alternative Transitional Registration model (ATRm) that reduces the data requirements for substances already registered under EU REACH, with full registration deadlines phased by tonnage band into the late 2020s. The HSE has also begun publishing its own regulatory management priorities, which means the UK candidate list and restriction pipeline will increasingly differ from ECHA's. If your compliance position assumes the two lists move together, it's worth re-checking, because they no longer do. Confirm the current statutory deadline for your tonnage band on the HSE website.

UK REACH requires manufacturers and importers to register substances, maintain updated SDS libraries, and respond to Article 33 requests from customers, all of which compound as your substance portfolio grows. Running it in parallel with EU REACH on disconnected spreadsheets is where the cracks first appear.

Worldover tracks every substance in your portfolio against the UK REACH register and flags divergences from EU REACH automatically. When a new SVHC is added, affected products surface immediately and Willow drafts Article 33 response templates and dossier update actions for the regulatory team to review. See how chemical compliance software handles both regimes from one substance master.