PCN format versions: v8, the annual cycle, and what changes

The PCN format is the structured data model every poison centre notification must follow: the fields, the picklists, the document structure and the validation rules that together define a submittable dossier. ECHA maintains it, versions it, and updates it roughly once a year. If you notify mixtures, the format version is not an implementation detail — it determines what your tools must produce today and what happens when you touch an old notification tomorrow. This article covers the current state, the cadence, and what a version change actually means in practice.

Current and previous versions

The current version is PCN format v8, in force since April 2026. It replaced v7, released in May 2025. The authoritative source for the current version — including the format definition, the XSD schemas for developers, and the annexed validation rules — is ECHA’s PCN format page, with the field-by-field narrative in the Guide to the PCN format.

A point of frequent confusion: the PCN format version is not the same thing as the IUCLID application version, though they travel together. The format is the data model; IUCLID (Cloud or desktop) is software that implements it. When ECHA ships a new IUCLID release, the PCN format update rides along, and .i6z dossiers are thereafter expected in the new format.

The roughly annual cadence

ECHA updates the format approximately once a year, aligned with its IUCLID release cycle — v7 arrived in May 2025, v8 in April 2026, both in spring. Releases are announced on the PCN format page and in ECHA’s poison centres news, with the updated documentation published alongside, so the arrival of a new version is easy to see coming. What is not predictable from the outside is the content of each update, which is why the release notes are worth ten minutes of your year.

Keep the moving and non-moving parts distinct when you plan. Label rules — the UFI, the CLP label elements — do not change with the PCN format, so a format release never forces an artwork change. What moves is the submission machinery: the fields your dossier must contain and the rules it must pass. That distinction decides who in your organisation needs to care about a release — regulatory operations and IT, not packaging.

What changes between versions in practice

Across recent cycles, version changes have meant some mix of:

• Field and picklist changes. New fields, retired fields, renamed options, updated phrase lists — including alignment with new EuPCS category list releases where relevant.
• Validation rule changes.New or tightened BR rules (which block submission) and QLT rules (which warn). A dossier that validated cleanly last year can fail this year’s rules without a single value changing — the rulebook moved. See PCN validation errors for how the two severities behave.
• Schema (XSD) changes. Relevant if you — or your software vendor — build dossiers programmatically for S2S submission: the XML structure itself is versioned, and integrations must be updated to emit the current schema.
• Documentation refresh. The Guide to the PCN format and the validation-rules annex are reissued per version; citing or working from an old PDF is a quiet source of avoidable errors.

For portal and IUCLID Cloud users, most of this is absorbed by the tools: the interface simply presents the new fields and runs the new rules. The people who feel format changes hardest are those with offline IUCLID 6 installations to upgrade, S2S integrations to re-test, or internal templates and SOPs that quietly encode last year’s field list.

What a format change means for existing notifications

The reassuring part first: notifications already submitted remain valid. A format update does not invalidate the dossier you filed under v7 or earlier, and there is no obligation to resubmit your portfolio each spring.

The operational part: any new submission or update must use the format current at the time you submit it. The moment a reformulation, a new pack size or a new market triggers an update to an old notification — the triggers are catalogued in how to update a PCN— that update is prepared in the current format, not the one the original was filed in. IUCLID migrates imported datasets forward largely automatically, but the new version’s fields and rules still apply, so an update can require data you were never asked for originally.

How to stay current

• Watch the source.ECHA’s PCN format page carries the current version, its documentation and the XSDs; the poison centres site announces releases. One calendar reminder each spring covers it.
• Re-check your references. After each release, replace stored copies of the format guide and validation rules with the current issue, and re-date any internal checklist derived from them (including your data-collection sheet from PCN required information).
• Confirm your toolchain.IUCLID Cloud updates itself; desktop IUCLID 6 and S2S integrations do not. If a vendor submits for you, their answer to “which PCN format version do you emit?” should be the current one, without hesitation.
• Validate early after a release. Run your next planned dossier through validation soon after a new version lands — surfacing a new BR rule in week two is far cheaper than discovering it against a launch deadline.

The pattern to internalise is that the PCN format behaves like any versioned interface: stable most of the year, stepped once a year, backwards-tolerant of what was already delivered but strict about everything new. Plan for the step and it is routine; ignore it and it surfaces as a blocked submission at the worst possible moment.