How limits are set
The standard for each analyte is the strictest maximum level set by any credible government regulator, among them the European Union, Codex Alimentarius, the US FDA, Australia/New Zealand, the Gulf states (GSO), and the national authorities of every jurisdiction that regulates the product, converted into Marine predatory fish (tuna, swordfish, shark, king mackerel, marlin)’s own as-consumed basis. It is a lookup of sovereign law, carrying at most one disclosed basis conversion where the law is written in another basis, and an explicit read-across where no government regulates the exact product. A certified product sits at or below every applicable sovereign limit at once.
Where no government regulates the exact product for an analyte, the standard does not go blank or invent a number: the limit is read across from the nearest government value for an analogous product, so a certified product still sits at or below a real sovereign limit. The ratchet tightens these after publication as surveillance warrants.
Master Limit Table
All values in ppb (µg/kg), as-consumed basis. Every analyte carries a firm ceiling. A brand meeting every value on a like-for-like basis qualifies for the mark.
| Analyte | Tier | HMTc limit | Binding basis |
|---|---|---|---|
| Lead (Pb) | Tier 1 | 200 | strictest government ML (Costa Rica) |
| Inorganic arsenic (iAs) | Tier 1 | 100 | strictest government ML (EU) |
| Total arsenic (tAs) | Tier 2 | 1000 | strictest government ML (Paraguay) |
| Mercury, total (tHg) | Tier 1 | 1000 | strictest government ML (EU) |
| Methylmercury (MeHg) | Tier 1 | 1000 | strictest government ML (Mexico) |
| Cadmium (Cd) | Tier 1 | 50 | strictest government ML (Costa Rica) |
| Nickel (Ni) | Tier 2 | 2000 | government read-across (EU) |
| Total chromium (Cr) | Tier 2 | 1000 | strictest government ML (Hong Kong) |
| Hexavalent chromium (Cr-VI) | Tier 2 | 10 | government read-across (US-CA) |
| Tin (Sn) | Tier 2 | 200000 | government read-across (EU) |
| Aluminium (Al) | Tier 2 | 100000 | government read-across (China) |
Tier 1 (Pb, iAs, Hg, MeHg, Cd) are zero-tolerance toxics with no established safe threshold. Tier 2 (tAs, Ni, Cr, Cr-VI, Sn, Al) are held to the same government limit: tiering sets how the program reacts to an exceedance, not any permission to exceed it. A product is certified only when every analyte is at or below 100% of its published limit; above the limit, on any metal, it is not certified and carries no mark. Mercury is limited in both forms: total mercury (tHg) and methylmercury (MeHg) are separate ceilings that must both be met, set to the species-specific tier each government assigns (predatory fish carry the higher methylmercury ceiling, lower-trophic species the lower; where the total-mercury ceiling is stricter, methylmercury is bounded by it). Total arsenic (tAs) operates as a reflex screen to inorganic-arsenic (iAs) speciation, since most arsenic in seafood is non-toxic organic arsenobetaine. 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, never an occurrence-derived number. Tin migrates from the can, so for non-canned seafood the read-across is a packaging-migration baseline that clean product clears.
Derivation
The full derivation for Marine predatory fish (tuna, swordfish, shark, king mackerel, marlin). Each row lists every government maximum level in force worldwide, converted to the as-consumed basis; the HMTc limit is the strictest of them, and the last column names which sovereign law binds. A blank cell means that government sets no limit for this analyte in this product.
| Analyte | EU | AU/NZ | GSO | India | Mercosur | Costa Rica | Fiji | Guyana | Israel | Morocco | Mexico | Panama | Philippines | Paraguay | Singapore | Thailand | Trinidad & Tobago | Vietnam | Hong Kong | HMTc | Binds |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lead (Pb) | 300 | — | — | — | 300 | 200 | 400 | — | 300 | — | — | 300 | — | 300 | — | — | — | 300 | — | 200 | Costa Rica |
| Inorganic arsenic (iAs) | 100 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 100 | EU |
| Total arsenic (tAs) | — | — | — | — | 1000 | — | — | — | 1000 | — | — | — | — | 1000 | — | — | — | — | — | 1000 | Paraguay |
| Mercury, total (tHg) | 1000 | 1000 | 1200 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | 1000 | — | 1000 | — | 1000 | 1000 | — | — | 1000 | — | 1000 | EU |
| Methylmercury (MeHg) | — | — | 1200 | — | — | — | — | — | — | — | 1000 | — | 1000 | — | — | 1000 | 1000 | 1000 | 1200 | 1000 | Mexico |
| Cadmium (Cd) | — | — | 100 | — | 100 | 50 | 100 | 100 | 250 | — | — | 100 | — | 100 | — | — | — | 100 | — | 50 | Costa Rica |
| Nickel (Ni) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 2000² | read-across |
| Total chromium (Cr) | — | — | — | 12000 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 1000 | 1000 | Hong Kong |
| Hexavalent chromium (Cr-VI) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 10² | read-across |
| Tin (Sn) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 200000² | read-across |
| Aluminium (Al) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 100000² | read-across |
All values µg/kg (ppb), as-consumed basis. ² no government regulates this analyte for this exact product form: the value is a disclosed read-across from the nearest applicable government maximum, and the derivation names the instrument it comes from. It is never taken from occurrence data. After publication the standards ratchet may tighten it, using certified-lot results only. ³ not material in this matrix: measured but with no standalone number, controlled by packaging control or by the total-metal screen, not an invented value.
Occurrence and derivation rationale
For each analyte on the panel: what the peer-reviewed and survey literature measured in this category, cited one way to the Heavy Metal Index, and the Method v2.0 reasoning behind the certification limit, including, where no government sets a number, why the program sets one anyway. Occurrence figures are literature findings; the derivation is the certifier's.
6 studies in the certified-market pool measured lead in Fish: marine, predatory across 596 certified-market samples. The pooled distribution centres on a median of 43 ppb and reaches 2.3 mg/kg at the 95th percentile. Ormaza-Gonzalez 2020, Lehel 2023, Lozano-Bilbao 2023, Depaiva 2017, Bhoyroo 2015, Smolikova 2016.
HMTc sets 200 ppb (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. The certified-market pool's P97 is 3.7 mg/kg (provisional), at or above the government ceiling of 200 ppb, so the government maximum binds. Why lead is limited →
1 study in the certified-market pool measured inorganic arsenic in Fish: marine, predatory across 45 certified-market samples. The pooled distribution centres on a median of 55 ppb and reaches 105 ppb at the 95th percentile. Lehel 2023.
HMTc sets 100 ppb (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. The certified-market pool's P97 is 107 ppb, at or above the government ceiling of 100 ppb, so the government maximum binds. Why inorganic arsenic is limited →
1 study in the certified-market pool measured total arsenic in Fish: marine, predatory across 50 certified-market samples. The pooled distribution centres on a median of 1.2 mg/kg and reaches 38.2 mg/kg at the 95th percentile. Lehel 2023.
HMTc sets 1 mg/kg (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. The certified-market pool's P97 is 41.2 mg/kg (provisional), at or above the government ceiling of 1 mg/kg, so the government maximum binds. Why total arsenic is limited →
7 studies in the certified-market pool measured total mercury in Fish: marine, predatory across 1955 certified-market samples. The pooled distribution centres on a median of 630 ppb and reaches 1.6 mg/kg at the 95th percentile, with a measured maximum of 2.9 mg/kg. Garofalo 2025, Ormaza-Gonzalez 2020, Depaiva 2017, Harding 2018, Lehel 2023, Brodziak-Dopierala 2023, Smolikova 2016.
HMTc sets 1 mg/kg (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. The certified-market pool's P97 is 1.9 mg/kg, at or above the government ceiling of 1 mg/kg, so the government maximum binds. Why total mercury is limited →
2 studies in the certified-market pool measured methylmercury in Fish: marine, predatory across 84 certified-market samples. The pooled distribution centres on a median of 198 ppb and reaches 813 ppb at the 95th percentile. Depaiva 2017, Harding 2018.
HMTc sets 1 mg/kg (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. The certified-market pool's P97 is 829 ppb, against a government ceiling of 1 mg/kg. Why methylmercury is limited →
5 studies in the certified-market pool measured cadmium in Fish: marine, predatory across 586 certified-market samples. The pooled distribution centres on a median of 23 ppb and reaches 152 ppb at the 95th percentile. Ormaza-Gonzalez 2020, Lehel 2023, Lozano-Bilbao 2023, Depaiva 2017, Smolikova 2016.
HMTc sets 50 ppb (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. The certified-market pool's P97 is 182 ppb (provisional), at or above the government ceiling of 50 ppb, so the government maximum binds. Why cadmium is limited →
1 study in the certified-market pool measured nickel in Fish: marine, predatory across 5 certified-market samples. The pooled distribution centres on a median of 403 ppb and reaches 655 ppb at the 95th percentile. Bhoyroo 2015.
HMTc sets 2 mg/kg by read-across: No government sets a nickel ML for animal seafood (EU 2024/1987 nickel covers plant foods and seaweed only). Read-across to the nearest whole-food nickel ceiling (EU 2024/1987 husked rice, 2000) that accommodates observed seafood nickel occurrence; clean product passes, grossly nickel-elevated product fails. Why nickel is limited →
12 studies in the corpus measured tin in Marine predatory fish (3617 samples reported across those studies): Jiang 2026, Uc-Peraza 2022, Wickramaarachchige 2022, Chung 2020, Kim 2019, Depaiva 2017, Lee 2016, Ho 2014 and 4 more.
HMTc sets 200 mg/kg by read-across: Tin is a can-migration analyte; no government sets a tin ML for non-canned seafood (every seafood tin ML is canned/tinplate-only). Read-across to the EU 2023/915 general canned-food inorganic-tin ML (200000) as a packaging-migration baseline; fresh/frozen predatory fish has no tin source and passes. Canned product is certified under the canned-seafood subcategory. Why tin is limited →
1 study in the certified-market pool measured aluminium in Fish: marine, predatory across 30 certified-market samples. The pooled distribution centres on a median of 7.5 mg/kg and reaches 30 mg/kg at the 95th percentile. Lozano-Bilbao 2023.
HMTc sets 100 mg/kg by read-across: No government sets an aluminium contaminant ML for food; dietary aluminium is managed by weekly intake against the EFSA/JECFA TWI. Read-across to the nearest food aluminium instrument (China GB 2760 baked-foods aluminium, 100000) as a monitor/baseline ceiling; clean product passes while gross contamination fails. Flagged monitor/baseline, not per-lot-critical. Why aluminium is limited →
Risk Flag
On the published occurrence literature to date, Marine predatory fish (tuna, swordfish, shark, king mackerel, marlin) shows no systematic gap between typical market levels and the limit: the limit being the strictest government maximum for the product (Method v2.0). Certification is decided on a product’s own tested result, not on a distribution; an individual lot or supplier can still exceed a limit.
See the cross-category summary of the ingredients that most often struggle.
Source regulations
Every published government regulation weighed to set this standard, evaluated against each other. The strictest applicable maximum level binds each analyte; the rest are comparators, and where no government regulates the exact product the value is read across from the nearest government limit. Follow a reference for the source document and its per-analyte limits: the Derivation table above shows every value side by side.
| # | Regulation | Year | Instrument | Role in this standard |
|---|---|---|---|---|
| 1 | Commission Regulation (EU) 2023/915 and (EU) 2025/1891 | 2023 | Maximum levels | Binds inorganic arsenic, total mercury; Read-across for nickel, tin; Comparator for lead |
| 2 | Costa Rica RTCR 409:2008: Reglamento de límites de contaminantes | 2008 | Maximum levels | Binds lead, cadmium; Comparator for total mercury |
| 3 | Mexico NOM-242-SSA1-2009 | 2009 | Maximum levels | Binds methylmercury |
| 4 | Paraguay Decreto 1335/2019 | 2019 | Maximum levels | Binds total arsenic; Comparator for lead, total mercury, cadmium |
| 5 | GB 2762: National Food Safety Standard | 2022 | Maximum levels | Read-across for aluminium |
| 6 | FSSAI (Contaminants, Toxins and Residues) Regulations | 2011 | Maximum levels | Comparator for total mercury, total chromium |
| 7 | GSO 193, Gulf Technical Regulation | 2021 | Maximum levels | Comparator for total mercury, methylmercury, cadmium |
| 8 | FSANZ Food Standards Code, Schedule 19 | 2015 | Maximum levels | Comparator for total mercury |
| 9 | Fiji Food Safety Regulations | 2009 | Maximum levels | Comparator for lead, total mercury, cadmium |
| 10 | Guyana Fisheries Products Regulations | 2023 | Maximum levels | Comparator for total mercury, cadmium |
| 11 | Israel Food Contaminants Standard (FCS) | 2016 | Maximum levels | Comparator for lead, total arsenic, total mercury, cadmium |
| 12 | Morocco Arrêté 2410-22 | 2022 | Maximum levels | Comparator for total mercury |
| 13 | MERCOSUR GMC Resolución 12/2011 | 2011 | Maximum levels | Comparator for lead, total arsenic, total mercury, cadmium |
| 14 | Panama Resolución 368/2009 | 2009 | Maximum levels | Comparator for lead, total mercury, cadmium |
| 15 | Philippines PNS/BAFS 194:2017 | 2017 | Maximum levels | Comparator for methylmercury |
| 16 | Singapore Food Regulations | 2023 | Maximum levels | Comparator for total mercury |
| 17 | Thailand MOPH Notification No. 414 | 2020 | Maximum levels | Comparator for methylmercury |
| 18 | Trinidad & Tobago Food and Drugs Regulations | 2007 | Maximum levels | Comparator for methylmercury |
| 19 | Vietnam QCVN 8-2:2011/BYT | 2011 | Maximum levels | Comparator for lead, total mercury, methylmercury, cadmium |
Cite this standard
Pendergrass, K. (2026). Marine predatory fish (tuna, swordfish, shark, king mackerel, marlin): HMTc standard (Standard No. 10.83138/hmtc.std.6.fish-marine-predatory). Institute of Contaminant Standards. https://doi.org/10.83138/hmtc.std.6.fish-marine-predatory
© 2026 Institute of Contaminant Standards / Heavy Metal Certified. All rights reserved.
The literature baseline for every analyte is maintained independently at the Heavy Metal Index. This certification standard applies those findings; the two are kept editorially separate by design.
Version history
The dated editions of this standard. Each is kept at a stable permalink, so a regulator or brand can reconstruct exactly what the standard required on any date: the edition record, not an editorial commit trail. Version-pinned DOIs link here once each edition is deposited.
| Version | Date | Status | What changed |
|---|---|---|---|
| v1.0 | 2026-08-07 | current | Initial publication. Government-limit standard (Method v2.0): each analyte is the strictest sovereign maximum for predatory fish by lookup, as-consumed basis. Mercury is limited in both forms (tHg 1000, MeHg 1000, the higher species-specific tier). Cadmium bound to 50 (Costa Rica general-fish ML, which does not except tuna/shark/marlin) after adversarial audit corrected an initial 100. |