ISCC Drops a Feedstock on 1 October — and 51 Thai Certificates Renew First

On 31 August 2026, ISCC published a batch of system updates. There was no press release and no consultation attached to the two that matter most. One of them takes a feedstock off the ISCC EU Material List on 1 October 2026. The other already changed what appears on the face of every ISCC EU and ISCC CORSIA certificate issued since 1 September 2026.

Both bind Thai exporters, and neither arrives with a letter. We queried ISCC’s public certificate database directly on the morning of 21 September 2026 to see how much of Thailand’s book sits in the path of these changes. The answer: most of it, and sooner than the calendar suggests.

What ISCC changed on 31 August — and what lands on 1 October

Both were published in the 31 August batch on ISCC’s system updates page.

First, the material list. The entry “Industry Food Waste Oil” is removed from the ISCC EU Material List with effect from 1 October 2026. ISCC is unambiguous about paper already in the market: “Certificates that include ‘Industry Food Waste Oil’ and were issued before 1 October 2026 may remain unchanged until their expiration.” System Users may transition to the entry “Food Waste” upon recertification, provided they meet the applicable definitions and requirements.

That is a reclassification with an evidence test attached, not a ban. Nothing is invalidated on 1 October. But the moment your certificate comes up for renewal, the entry you have been using is gone, and the replacement entry carries its own definition you must demonstrate you satisfy.

Second, the chain-of-custody field. For ISCC EU and ISCC CORSIA certificates issued from 1 September 2026, certification bodies “must indicate the applicable chain of custody option verified during the audit (‘Mass Balance’ or ‘Physical Segregation’)”. The field does not apply to traders without storage capability.

The same batch also introduced new GHG transport exhaust-emission requirements under ISCC EU, with distances calculated by a longest-distance, weighted-average, or individual-contract approach — applied consistently throughout.

Thailand’s ISCC book, counted this morning

ISCC’s searchable certificate database is machine-queryable. Pulled on 21 September 2026, Thailand holds 197 valid certificates: 100 under ISCC PLUS, 67 under ISCC EU, and 30 under ISCC CORSIA. Globally the database showed 16,403 valid certificates the same morning, of which 821 were CORSIA.

Those two pairs of numbers give the most interesting fact about Thailand’s position: it holds 1.2% of all valid ISCC certificates but 3.7% of all valid CORSIA certificates — an over-index of roughly three times. Within ASEAN, Thailand’s CORSIA share of its own book, 15.2%, is the highest in the region.

Thailand is fifth in ASEAN on volume and first on aviation-fuel orientation — the profile of a feedstock and intermediate exporter feeding someone else’s refinery, not a domestic consumption market. The scope split says the same: 100 Processing Units, 76 Collecting Points, 72 Traders with Storage, 27 Traders, and only 17 Points of Origin.

And the book turns over fast. 51 of Thailand’s 197 certificates expire within 90 days — by 20 December 2026 — and 99 within 180 days. Half the country’s ISCC paper will be re-audited and reissued inside six months, under the rules as they stand after 1 October.

The four certificates that name the feedstock being removed

Four Thai certificates currently name “Industry food waste oil” among their raw materials. All four are ISCC EU certificates. Their remaining validity, measured from 21 September: 1 day, 115 days, 120 days and 158 days.

All four therefore fall due for recertification inside the next six months — under a material list that no longer carries the entry they were issued against. Three have enough runway to prepare the transition properly. One does not.

The surrounding exposure is larger. Thailand’s certified feedstock book is dominated by waste and residue streams: 64 certificates naming used cooking oil, 15 naming palm oil mill effluent (POME) oil, and 13 naming palm fatty acid distillate (PFAD). That last one is named in EU law — and not favourably.

Used cooking oil sits in Annex IX Part B and counts. PFAD is named and excluded unless it qualifies under Annex IX. A Thai producer holding both on one certificate is running two feedstocks with materially different standing in the buyer’s compliance arithmetic — exactly the kind of distinction that has to survive into the documents a European offtaker reads.

Every Thai certificate is issued from somewhere else

ISCC publishes the list of certification bodies it recognises. None is domiciled in Thailand. The certificate records confirm it from the other direction: Thailand’s 197 certificates were issued by bodies based in Germany (74), Poland (66), Malaysia (25), Indonesia (18), the United States (9), Latvia (2), China (2) and India (1). Indonesia has seven recognised CBs on its own soil, Malaysia three, Singapore two. Thailand has none.

So every recertification audit in Thailand is conducted by an organisation headquartered somewhere else, and ISCC has a rule for what happens when the auditor and the site do not share a working language.

Here is where the honest line sits, and it matters that we draw it clearly. That provision binds the audit report — a document the certification body writes, not one you write. Nothing in ISCC requires your own mass-balance books, delivery notes, supplier declarations or internal assessment to be in English. Your records may be in Thai. ISCC’s self-declaration templates exist in multiple languages. Anyone telling you ISCC mandates English-language records is selling you something that is not in the standard.

What the clause does establish is narrower and more practical: the translation should happen “ideally in advance of the audit”, by an independent translator. The documents an auditor can read before arriving are the documents that get assessed inside the audit window — and that window is not generous. A certificate must issue within 60 days of the audit, and that same window has to absorb up to 40 calendar days of non-conformity correction. Work backwards and the audit falls roughly two months before expiry, with the evidence already legible when the auditor opens it.

That is a scheduling and accuracy argument, not a legal one — the difference between translating your traceability evidence deliberately, in advance, to a standard you control, and translating it across a table while a finding is being written up. We build the first kind through an ISO 17100 Translate–Edit–Proofread process, and have written elsewhere on what goes wrong when that work is treated as clerical.

One point of transparency: ISCC restructured its website during 2026 and the ISCC EU system documents now sit behind a client-section login. The validity, issuance and correction periods above come from our own earlier verbatim reading of ISCC EU 201 §4.2.1 and §4.2.3 and ISCC EU 203 §4.4.1; the PLUS 103 wording we re-read at source today. Where we could not re-open a document this week, we say so.

The chain-of-custody field is not cosmetic

The chain-of-custody field looks administrative. It is not. From 1 September 2026, an ISCC EU or CORSIA certificate states on its face whether the holder was verified under Mass Balance or Physical Segregation. Ninety-seven of Thailand’s 197 certificates are EU or CORSIA, and 46 of those expire within 180 days — so they will be reissued carrying the field.

Two consequences follow. Internally, your declared model has to match what your books actually do; a mass-balance claim on the certificate and a segregation-shaped reality in the warehouse is a finding waiting to be written. Externally, a European buyer comparing two Thai suppliers can now read the model straight off the certificate without asking either of them. That is a disclosure — and like every other disclosure, it is only an advantage if it is accurate.

Where ISCC audits actually go wrong

ISCC reports annually to the European Commission. The latest edition — Report to the European Commission for the Calendar Year 2025, submitted 30 April 2026 — is the closest thing the scheme has to published audit statistics.

The most common major and critical non-conformities named in that report are worth reading as a list, because they are almost entirely evidentiary: inability to demonstrate traceability of sustainable materials and products; missing or delayed cooperation in the Integrity Programme; missing or delayed cooperation in surveillance audits requested by the certification body; non-compliance with EU reporting requirements; denied access to supplying points of origin; and false declaration or relabelling of material in the context of waste and residues.

The fair reading of these numbers is not alarming. Roughly 98.4% of certificates were not withdrawn, and most holders renew without incident. The 71.2% Asia figure is a risk-targeted allocation of assessments, not a regional failure rate — ISCC directs integrity work where waste-and-residue supply chains concentrate, which is where Thailand’s book sits. It is a statement about where scrutiny lands, not about who fails.

One more thing to hold lightly. On 15 September 2026 ISCC published results from its working group on chemical characterisation of used cooking oil — an inter-laboratory study across 18 samples, five regions and nine laboratories. If a vendor tells you ISCC has introduced UCO testing requirements, they are wrong. ISCC says the screening tool is “a research outcome of the working group, not embed[ded] in certification processes”, and that “no universal standard values could or should be defined”. It is a signal about where audit risk-assessment is heading. It is not a rule.

What to do in the next ninety days

None of this is a crisis. It is a calendar. The scheme changed two things quietly, half of Thailand’s certificate book renews before those changes have had six months to settle, and the audits are run by people arriving from abroad who will read whatever you have made readable.

Othello prepares that evidence base — gap assessment, internal assessment, mass-balance review and the English document set behind it. We are not a certification body, we do not audit and we do not issue certificates; ISCC’s own terms prohibit the body that audits you from preparing you, which is precisely why preparation is a separate job. This sits alongside our ISCC certification support, TGO CFO carbon footprint and CBAM practices, with the wider picture on our ESG regulatory tracker. See how we work, or how verified carbon numbers travel into disclosure.