Almost every cashew price list in the world quotes grades like W240, W320, or SW without ever saying which formal standard defines what those letters and numbers actually guarantee — and that gap is where real commercial disputes come from. Two internationally codified documents sit underneath the trading terminology that buyers and sellers throw around casually: ISO 6477:1988, maintained by the International Organization for Standardization, and UNECE Standard DDP-17, maintained by the United Nations Economic Commission for Europe. A third system, the AFI Specifications for Cashew Kernels, governs the familiar W-series grades most exporters actually quote against. Understanding how these three relate — and, more importantly, which one a given contract is actually invoking — is one of the more consequential but least-explained pieces of cashew trading knowledge.
What ISO 6477 actually defines
ISO 6477:1988, titled Cashew Kernels — Specification, is the globally recognised international standard for cashew kernel grading, defining 24 distinct kernel grades along with moisture limits, sampling procedures, and test methods. It remains the active international reference today — it was formally reconfirmed as recently as 2024, meaning ISO’s periodic review process re-evaluated the standard and chose to keep it in force rather than revise or withdraw it. What ISO 6477 does that a lot of informal grading talk skips over is specify not just the grade names but the testing methodology behind them: how a sample is drawn, how moisture is measured, and what counts as a defect for classification purposes. A grade name without that underlying test method attached is really just a label, not an enforceable specification — which is exactly the ambiguity that causes disputes later.
What UNECE DDP-17 actually defines
UNECE Standard DDP-17 — Cashew Kernels is the grading standard most European buyers actually reference directly in purchase contracts, adopted in 2012 with technical input from the International Nut and Dried Fruit Council (INC). It covers presentation types (whole kernels, butts, splits, and pieces), sets a 5% moisture ceiling, defines three quality tiers, and lays out sizing categories, defect tolerances, and packaging and labelling requirements. Where ISO 6477 reads more like a laboratory specification, UNECE DDP-17 reads more like a trading rulebook — it’s built specifically for commercial buyers and sellers to reference in contracts, which is a large part of why it has become the default citation for European purchase agreements rather than a niche technical document.
Where AFI’s W-series grades fit in
The W180/W210/W240/W320/W450 numbering that dominates everyday cashew trade talk — along with SW (scorched wholes) and LWP (large white pieces) — comes from the Association of Food Industries (AFI), a US-based trade organisation whose Specifications for Cashew Kernels form a separate, US-market-oriented grading rulebook. The numbers refer approximately to kernel count per pound, so a lower number means larger, more valuable kernels. AFI’s specifications overlap substantially with ISO 6477 and UNECE DDP-17 in spirit — larger, whole, unblemished kernels rank higher across all three systems — but the specific defect tolerances, moisture handling, and grading mechanics are not identical line-for-line. Treating “W320” as a self-explanatory, universally understood term, without specifying whether it’s being graded under AFI, ISO 6477, or UNECE DDP-17 rules, is exactly the kind of imprecision that gets exploited — intentionally or not — when a shipment arrives and a dispute over quality begins.
A worked example of grading-dispute risk
Consider a contract that simply states “500kg W320, good quality” with no standard cited. The exporter ships kernels that would pass comfortably under AFI’s typical W320 tolerances. The buyer, working from a European retail relationship, inspects the shipment against UNECE DDP-17’s defect and moisture criteria — a standard the exporter never agreed to in writing, but one the buyer reasonably assumed applied given the shipping destination. The shipment gets flagged for exceeding acceptable moisture content or defect count under UNECE’s tighter presentation rules, even though it would have passed under AFI’s own W320 tolerance. Now there’s a genuine commercial dispute, and because the contract never named a governing standard, resolving it comes down to negotiation and goodwill rather than a clear, citable reference document either party can point to. Multiply that scenario across dozens of containers a year and the cost of ambiguous contract language becomes very real — far more expensive than the five minutes it would have taken to write “graded to AFI W320 specification” or “graded to UNECE DDP-17, Extra Class” explicitly into the purchase agreement.
Why citing the specific standard in contracts matters
The practical fix is simple and costs nothing: name the governing standard explicitly in every contract, alongside the grade. “W320 per AFI Specifications for Cashew Kernels” and “Extra Class per UNECE Standard DDP-17” are precise, enforceable, and leave far less room for a good-faith disagreement to turn into a costly dispute. This becomes especially important as more buyers — particularly in the EU — request documentation tying grading claims to a named, internationally recognised standard rather than accepting a seller’s informal assurance. For a working definition of every individual grade term referenced here, see the Cashew Processing Glossary and the full cashew grade chart, and for how grading interacts with the equipment used to sort and size kernels in the first place, see the AI and computer-vision cashew sorting page and the broader cashew equipment buyer’s guide. Exporters working with Vietnam-origin kernel, the largest processed-cashew source globally, should also see the VINACAS guide for how Vietnamese grading practice intersects with these international standards.
This page summarises current grading-standard content for general reference. Standards bodies periodically review and revise their documents — always confirm the current, in-force version of ISO 6477, UNECE DDP-17, or the AFI specifications directly with the issuing body before relying on it for a specific contract.