What is a UFI?

A UFI is one of two obligations that come with placing a mixture classified for a health or physical hazard on the EU market, alongside the PCN dossier itself. The two are meant to be read together: the code is short enough to fit on a label, and the dossier behind it holds everything a poison centre needs once that code has been read out over the phone.

The 16-character code

A UFI is a string of 16 characters, presented in four blocks of four separated by hyphens — for example UFI: 1234-A56B-700D-9E1F — and always shown with the UFI: prefix wherever it appears, so it reads as a UFI rather than as a batch number or some other code printed near it on the label. The character set is alphanumeric, and it is deliberately restricted to cut down on characters that are easy to misread when someone is copying a code off a label under pressure.

The code itself is generated, not chosen. It is derived from your company's VAT number and a formulation number you assign to that specific composition, run through a fixed algorithm that also builds in a check character, details specified in the ECHA UFI Developers Manual. Two companies never arrive at the same UFI from different inputs, and the same pair of inputs always produces the same UFI.

What the UFI links

The UFI is the only connector between what a consumer or a first responder can see on the label and what your company has declared, in full, inside the PCN dossier. It does not describe the mixture itself — it points to a record. The rule that makes the whole system work is that the same UFI always means the same composition: if a formulation changes in a way that matters for emergency response, the UFI has to change with it, so the code on the shelf never points a poison centre to a composition the product no longer has.

How a UFI is generated

You do not write a UFI by hand. It comes out of ECHA's UFI Generator, fed by your VAT number and a formulation number that you choose to represent this specific composition — the same two inputs will always generate the same code, which is what makes the system reproducible across a company's whole product range. Get the VAT number wrong, or reuse a formulation number for a composition it was never meant to represent, and the code that comes out is still valid-looking, but it stops meaning what it is supposed to mean. The mechanics of the generator, including how a formulation number is chosen and how a batch of UFIs is created in one pass, are covered on our UFI Generator page.

Where it appears

The UFI belongs on the label of the mixture, alongside the other CLP hazard information, and it also has to appear in the composition section of the safety data sheet. Packaging too small to carry a full label, and mixtures supplied without individual packaging, follow their own placement rules rather than being exempt from carrying a UFI at all. Getting the placement or the formatting wrong is a labelling defect in its own right, separate from whatever else might be missing from the dossier behind the code. The full placement and formatting requirements are set out on our UFI label page.

What the UFI does not reveal

A UFI cannot be decoded back into a composition by anyone who only has the code. It is a reference number, not an encoded ingredient list, so a competitor reading a label — or a customer, or a customs official — learns nothing about what is actually in the mixture from the UFI itself. The full composition only becomes visible to the poison centres that receive the PCN dossier through the official submission channel, and to nobody else. That is also why the UFI is worth getting right rather than treating as a formality: it is doing the confidentiality work that lets a company disclose a full composition to a poison centre without that composition becoming public. How that confidentiality is preserved, and what it does and does not protect, is covered on our confidentiality page.

One UFI, many products

The UFI is tied to a composition, not to a product name. If your company sells the same formulation under several trade names, or a distributor rebrands it for a different market, all of those products can carry the same UFI, because a poison centre needs to know what is inside the packaging, not what the label calls it. That also means one dossier and one formulation number can quietly cover a whole family of branded products, which is useful when a portfolio is larger than the number of genuinely different compositions behind it.

What can never happen is the reverse: two mixtures with different compositions sharing one UFI, because that would point a poison centre at the wrong data in exactly the situation the whole system exists to handle. Where the line falls between a labelling change you can make freely and a composition change that needs a new code of its own is set out on our page on when a new UFI is needed.