When does a UFI change? The composition triggers under Annex VIII

A UFIidentifies exactly one mixture composition. That invariant is only useful if everyone agrees on what “the composition changed” means — and Annex VIII to CLP does not leave it to judgement. Part B Section 4.1 defines the triggers numerically, and Part A Section 5.1 ties the new-UFI duty to those same triggers. Getting this wrong in either direction is expensive: a missed new UFI means the label points poison centres at the wrong recipe; an unnecessary one means reprinted labels, a fresh notification and confused stock control for nothing.

The legal test

Annex VIII requires a new UFI when a change in the composition of the mixture meets one of the conditions in points (a), (b) or (c) of the fourth indent of Part B Section 4.1. Everything else — trade names, packaging, classification, contact details — may require a notification update, but never a new UFI. The test applies only to components that must be reported in the submission in the first place: a change in a component that is not classified for health or physical effects and sits below 1% is invisible to the rule.

The three composition triggers

Trigger (a): adding, substituting or deleting a component.Any addition, substitution or deletion of a reportable component is a new composition, full stop. One nuance from ECHA’s guidance is worth committing to memory: substituting a component with another of identical composition and hazard profile — typically the same substance from a new supplier — does not count. Substitution means chemically different material.

Trigger (b): leaving the declared range. If your submission declared a component at 5–10% and the new batch formula calls for 12%, the composition has left the notification. Movement within the declared range is free — which is why the width you choose at submission time (bounded by Tables 1 and 2 of Annex VIII) is a genuine design decision, not a formality.

Trigger (c): drifting beyond the exact-value tolerances. If you declared exact concentrations, Table 4 of Annex VIII allows bounded drift before a new UFI is due:

The MiM cascade

If your mixture contains a mixture in mixtureidentified by the supplier’s UFI, your composition can change without you touching the formula. When the supplier reformulates the MiM and issues a new UFI, your mixture’s composition has changed too: you must reflect the new MiM UFI in your notification andissue a new UFI for your final mixture. The one escape: if the supplier changed the MiM’s UFI for purely commercial reasons and confirms the composition is unchanged, you update the MiM reference but keep your own UFI. That confirmation is why supplier change-notice commitments belong in your raw-material contracts.

What does not change the UFI

• Concentration moves within the declared range, or within the Table 4 tolerance for exact values. No update, no new UFI.
• Perfume changes inside a group submission. In a group submission whose members differ only in perfumes, changing or adding perfume components does not require a new UFI — though the group’s list of mixtures and their perfumes must be updated, and removing a perfume from every mixture in the group triggers an update too.
• Swaps inside an interchangeable component group (ICG). A change confined to components already grouped in an ICG in the original submission keeps the UFI. Adding a new ICG, or replacing an individually declared component with an ICG, is a different matter — that requires a new UFI.
• Same-for-same supplier changes — identical composition and hazard profile.
• Packaging, branding and label changes. New pack sizes and new trade names are notification updates, never UFI events. A company may still voluntarily issue a new UFI on a commercial rebrand; then the notification is updated for a change in the product identifier.
• Classification or toxicology changes alone. Both require an update; neither touches the UFI unless a composition change caused them.

New UFI always means an updated notification — first

A new UFI is never a standalone act. Crossing any composition trigger means submitting what the PCN system calls a new notification after a significant change of composition — technically a new record, linked to the old PCN number — and Annex VIII requires it before the changed mixture is placed on the market. The sequence is fixed: generate the new UFI, submit the notification, then ship product carrying the new code. Stock already on the market keeps the old UFI, and the old record stays live precisely because both versions may sit on shelves for years. The mechanics of generating the code itself are covered in how to generate a UFI; the submission mechanics in how to submit a PCN.

Version discipline for your formulation register

Every trigger above is evaluated against what you declared, so the register that maps formulations to UFIs must record the declaration, not just the recipe. A register that survives audits has five properties:

1. One formulation number per composition, never recycled. The formulation number is a UFI input; reusing it for a revised recipe would regenerate the old code for a new composition — the one failure the system cannot tolerate.
2. The declared ranges and exact values stored beside the recipe. Whether a batch change needs a new UFI depends on the submitted numbers, and Table 4 drift is cumulative against the original submission.
3. MiM references with supplier UFI, market coverage and the latest change confirmation— the cascade begins in someone else’s change-control system.
4. A status per UFI: on market, superseded (still on market), or withdrawn. Old UFIs are not retired when a new one issues.
5. A gate in the change process: no reformulated batch is released until the new notification’s submission is confirmed. The regulation sequences notification before market, and your workflow should make the wrong order impossible.

This is bookkeeping, but it is exactly the bookkeeping that determines whether a reformulation costs you an afternoon or a finding. Ufi Number keeps the formulation-number ledger and derives UFIs deterministically from it, so the register and the codes cannot drift apart.