CBAM's definitive period is set for 2026, upgrading the mechanism from the transition phase's report-only stance to paying the carbon price. Free allowances phase down on a fixed curve to zero by 2034, and the first round covers six sectors - steel, aluminium, cement, fertilizers, electricity and hydrogen. Petrochemicals are not in the opening scope, but the product-carbon-footprint (PCF) preamble is already written into upstream and downstream procurement terms.

For a player like SNSUC that runs crude transfer and chemical trading, there is no direct carbon-tax bill in the short run, yet two things are unavoidable: EU buyers now ask suppliers for batch-level PCF as a procurement precondition, and the carbon data on bills of lading, warehouse receipts and inspection certificates must corroborate each other.

In practice, hashing each batch's energy use and emissions into SHA-256 produces a browser-recomputable fingerprint that can be attached to a cross-chain interoperable warehouse receipt, turning the carbon ledger from a self-declared document into a verifiable asset. With Brent at $108.32/bbl today, the energy-side carbon-cost base is not low; the earlier batch-level carbon data is fixed, the less retrospective material is needed during buyer due diligence.

On the compliance red line: carbon-data attestation only proves the energy footprint of a given batch and does not expose any due-diligence backstop beyond origin checks. Iran remains the sole auto-reject origin and Iraq is exempt; that line stands alongside the carbon ledger and neither replaces the other.