Insights - Your IUCLID 5 File Won't Go Into KKS

On 31 July a Hungarian manufacturer sent us two files ending in .i5z with one short question: can Türkiye accept these?

The honest answer was no. Not as they were.

Why an IUCLID 5 file stops at the Turkish border

Registration under KKDİK, Türkiye’s counterpart to EU REACH, runs through KKS (Kimyasal Kayıt Sistemi), the Ministry’s registration system. KKS is aligned to the IUCLID 6 data structure. A dossier last saved in IUCLID 5 does not go in as it is.

That would be a minor inconvenience if there were an official converter. There is not. ECHA handled the move from IUCLID 5 to 6 inside the application years ago: you opened your old data in a new installation and it migrated. A company that never ran that upgrade, or that only kept the exported .i5z files, is left with archive files that no current tool reads.

For EU REACH that was a solved problem long ago. For KKDİK it is live again, because many substances registered in the EU a decade ago now have to be registered in Türkiye, and the data for them sits in exactly those archives.

The calendar

From the Ministry’s implementation rules (Usul ve Esaslar, 5 August 2025) and Geçici Madde 2 of the regulation:

One caution. Several consultancy summaries present 30 September as a blanket “register or leave the market” date. The primary text is narrower: 30 September is the deadline for member firms, after their lead has filed. In a compliance conversation, quote the Ministry, not the summary. The Kimyasallar Yardım Masası is the reference.

What matters for planning is the shape: not one deadline but four waves through 2030. Each one pulls another batch of old IUCLID 5 data out of the archive.

Who actually files the data

Two roles decide how this works in practice.

• Only Representative. A manufacturer outside Türkiye cannot register under KKDİK itself. It appoints a Türkiye-based Only Representative, the same construct as under EU REACH.
• KDU. Data is entered into KKS by a Kimyasal Değerlendirme Uzmanı, a chemical assessment expert holding a Ministry certificate. EU REACH has no equivalent gate.

So the buyer of a conversion is rarely the exporter. It is the Only Representative or the consultancy, and the constraint is the KDU’s calendar. A file that still needs converting when the KDU is ready to enter it costs a slot nobody gets back.

How the conversion works

We do not re-key data and we do not map fields by guesswork. The conversion runs the real software end to end:

1. The IUCLID 5 file is read and validated with the genuine IUCLID 5 engine.
2. A headless IUCLID 6 imports it, and ECHA’s own 5 → 6 structure mapping migrates the data.
3. A valid .i6z is exported and returned with a short QA summary.

Batch conversion handles whole archives. Files are processed in the EU and deleted afterwards.

What to do this quarter

• Find the files. Ask every client exporting to Türkiye whether their registration data exists only as .i5z or .i5a. The answer is often “somewhere on a share”.
• Convert before the KDU slot, not during it. Especially ahead of the 31 December wave for ≥ 1,000 t/a substances.
• Keep one IUCLID 6 per client. An Only Representative acting for several exporters needs their data separated. That is what hosting for consultants is built for.

KKDİK is one of several REACH-like regimes with their own systems; we wrote about the wider pattern in REACH Went Global. Your Dossiers Didn’t.

Holding legacy IUCLID 5 files? We convert them to IUCLID 6 free of charge. Details on the KKDİK conversion page (also in Turkish), or send us a sample.