Scope and method
Every limit on every subcategory is the strictest maximum level set by any credible government worldwide, converted to the product’s native basis, with a disclosed read-across from the nearest government value where no government regulates the exact product. Nothing is invented; every number traces to a named sovereign limit in the regulation references.
Method: government-limit default (Method v2.0). Seafood limits are taken at face value in each product’s native basis; there is no reconstitution conversion. Mercury is limited in both forms, total mercury (Hg) and methylmercury (MeHg), set to the species-specific tier each government assigns (predatory fish carry the higher ceiling, lower-trophic species the lower; where the total-mercury ceiling is stricter, methylmercury is bounded by it). Every claim analyte is equal at the gate: a product is certified only at or below 100% of each published government floor or disclosed read-across. An exceedance on any metal enters Remediation unmarked; there is no transitional overage. Total arsenic operates as a reflex screen to inorganic-arsenic speciation. Every panel analyte carries a limit of record; where no government regulates the exact product (nickel, hexavalent chromium, aluminium, and non-canned tin), the ceiling is a disclosed read-across to the nearest applicable sovereign instrument named in the derivation. Tin migrates from the can, so for non-canned seafood the read-across is a packaging-migration baseline.
Master limit matrix
All values ppb (µg/kg) in each row’s native basis. Click any subcategory for its full government-by-government derivation. n/m = not material in the matrix; controlled by screen or reflex speciation, not a number.
| Subcategory | Pb | iAs | tAs | Hg | MeHg | Cd | Ni | Cr | Cr-VI | Sn | Al | Basis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Marine predatory fish (tuna, swordfish, shark, king mackerel, marlin) | 200 | 100 | 1000 | 1000 | 1000 | 50 | 2000 | 1000 | 10 | 200000 | 100000 | as consumed |
| Marine non-predatory fish (sardine, anchovy, salmon, cod, herring, mackerel) | 200 | 100 | 1000 | 300 | — | 50 | 2000 | 1000 | 10 | 200000 | 100000 | as consumed |
| Freshwater fish (tilapia, catfish, trout, carp) | 200 | 100 | 1000 | 300 | — | 50 | 2000 | 1000 | 10 | 200000 | 100000 | as consumed |
| Shellfish (crustaceans and bivalve molluscs) | 500 | 100 | 1000 | 500 | 500 | 500 | 2000 | 1000 | 10 | 200000 | 100000 | as consumed |
| Cephalopods (octopus, squid, cuttlefish) | 300 | 50 | 1000 | 300 | — | 1000 | 2000 | 12000 | 10 | 200000 | 100000 | as consumed |
| Seaweed & kelp foods (nori, wakame, kombu, dulse) | 5000 | 1000 | 5000 | 100 | — | 500 | 30000 | 2000 | 10 | 200000 | 100000 | as sold |
| Canned seafood (canned tuna, canned fish) | 200 | 100 | 1000 | 500 | 500 | 50 | 2000 | 1000 | 10 | 100000 | 100000 | as consumed |
Risk Flag
These subcategories carry a natural or process background that runs above the limit — the limit being the strictest government maximum for the product, never a percentile of market data (Method v2.0). A product is not disqualified by this: only its own tested result decides certification, and a well-sourced lot can sit well below the market. What the pooled occurrence literature shows is where the work is — which ingredients demand exceptional sourcing.
Inorganic arsenic
Inorganic arsenic is taken up from soil, irrigation water, and seawater; rice and rice-derived ingredients, and some seaweeds, carry it far above the strictest sovereign limits.
Cadmium
Cocoa, leafy greens, sunflower and other seeds, organ meats, shellfish, seaweed, and some root vegetables concentrate cadmium from soil and seawater.
Nickel
Legumes, nuts, cocoa, and oats are naturally high in nickel.
Multipliers are the ratio of the pooled occurrence median to the published limit; occurrence characterises the market only and carries no compliance weight. See the cross-category summary.
About this edition
Standards are living, versioned documents; each subcategory page carries its own version history and dated change log. This is the current web edition. A consolidated, version-pinned PDF of the full manual is in preparation and will be linked here on release; until then each subcategory page is individually citable.
The literature baseline underlying these certification limits is maintained independently at the Heavy Metal Index. This certification standard applies those findings; the two are kept editorially separate by design.