REACH (Regulation EC 1907/2006, and its UK assimilated equivalent) is built on a simple principle, no data, no market. If you manufacture or import a substance into the EU or GB above one tonne per year, you register it with ECHA or with the HSE, with a dossier proportionate to the tonnage band. If the substance is on the Candidate List of Substances of Very High Concern, you have communication and notification duties. If it is on Annex XIV you need an authorisation. If it is on Annex XVII you operate under a restriction. Downstream users have their own narrower set of obligations.

The challenge is rarely understanding any single obligation. It is keeping all of them current across a portfolio of hundreds of substances, two jurisdictions (EU and GB) that are starting to diverge, and a Candidate List that grows twice a year.

At minimum, a REACH platform covers six things. A substance inventory keyed off CAS and EC numbers, with synonyms and INCI cross references. Tonnage tracking per legal entity per substance, with rolling twelve month aggregates that trigger the right registration band. Registration and dossier management, including joint submission status, lead registrant identity and IUCLID file versioning. SVHC monitoring against the Candidate List, with automatic flagging of every product that contains a newly listed substance above the threshold. Annex XIV and Annex XVII tracking, with sunset dates and restriction scope. Article 33 communication workflows for SVHCs in articles above 0.1 percent by weight.

Anything that does not cover these six is not REACH software. It is a spreadsheet with a login.

The dividing line is whether the substance master is shared with the rest of the regulatory and operational stack. In a tracker, the REACH module has its own inventory, the SDS authoring tool has its own inventory, the formulation system has its own inventory, and someone reconciles them quarterly. In a platform, there is one substance master. A change to a classification, a tonnage band or an SVHC flag propagates immediately to SDSs, to CPSRs and PIFs on the cosmetics side, to the procurement system on the supplier side, and to the customer portal on the distribution side.

The tracker model is acceptable for a small portfolio in a single market. It breaks above roughly a hundred substances or above one jurisdiction. The reconciliation work becomes the job.

Since Brexit, EU REACH and UK REACH have been separate regulations under separate competent authorities (ECHA for the EU, HSE for GB). The substantive text is largely shared but the registration regimes are independent, the Candidate Lists can diverge, and Annex XIV and XVII can take different paths. GB transitional arrangements (DUIN, then UK registration) have a different deadline schedule from the original EU REACH deadlines.

Any serious platform models both regimes against the same substance master and surfaces the divergences explicitly. The wrong design is two parallel modules with two parallel substance inventories. The right design is one substance, with one EU dossier and one GB dossier as projections.

The hazard classifications agreed in the REACH registration are the same classifications that drive CLP labelling and section 2 of the SDS. The exposure scenarios attached to the registration become the annexes of the extended SDS (eSDS) for downstream users. The DNELs and PNECs in the registration drive section 8 of the SDS.

Treating REACH, CLP and SDS as three systems is a familiar source of pain. A classification updated in the registration that never makes it onto the SDS is a compliance failure that an audit will find. The architectural answer is one substance, one set of classifications, three outputs.

Ask the vendor four things. One, show the SVHC Candidate List integration, end to end, with the date of the most recent update reflected in the platform. Two, show a registration dossier opened, edited and re submitted, with version history and IUCLID export. Three, show how the same substance carries EU REACH and UK REACH status side by side. Four, show Article 33 communication for an article containing a newly listed SVHC above 0.1 percent. If those four flow cleanly from one substance record, the platform is real. If any of them requires jumping into another tool, the architecture is the wrong one.