How every number on this page is 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 Soy products (soybeans, edamame, tofu, tempeh, soy flour, and other whole-soy foods)’s own as-sold 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-sold basis. 7 of 11 analytes carry a firm ceiling; the remainder are governed by mandatory control or reflex-speciation screening with no standalone number, itemised in the derivation below. A brand meeting every firm value on a like-for-like basis, and passing every control, qualifies for the mark.
| Analyte | Tier | HMTc limit | Binding basis |
|---|---|---|---|
| Lead (Pb) | Tier 1 | 200 | strictest government ML (Mercosur) |
| Inorganic arsenic (iAs) | Tier 1 | 100 | strictest government ML (Israel) |
| Total arsenic (tAs) | Tier 2 | 1000 | strictest government ML (Israel) |
| Mercury, total (tHg) | Tier 1 | 30 | strictest government ML (Israel) |
| Methylmercury (MeHg) | Tier 1 | n/m | not material — controlled analyte (see note) |
| Cadmium (Cd) | Tier 1 | 200 | strictest government ML (EU) |
| Hexavalent chromium (Cr-VI) | Tier 2 | n/m | not material — controlled analyte (see note) |
| Nickel (Ni) | Tier 2 | 6000 | strictest government ML (EU) |
| Tin (Sn) | Tier 2 | n/m | not material — controlled analyte (see note) |
| Aluminium (Al) | Tier 2 | control | mandatory control — no government ML; screened every lot (see note) |
| Total chromium (Cr) | Tier 2 | 1000 | strictest government ML (China) |
Tier 1 (Pb, iAs, Hg, MeHg, Cd) are zero-tolerance toxics with no established safe threshold. Tier 2 (tAs, Cr-VI, Ni, Sn, Al, Cr) carry a 150% transitional allowance under the program’s Status A–E framework.
Derivation — every government’s number, side by side
The full derivation for Soy products (soybeans, edamame, tofu, tempeh, soy flour, and other whole-soy foods). Each row lists every government maximum level in force worldwide, converted to the as-sold 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 | GSO | China | Mercosur | Israel | Paraguay | CO | CH | HMTc | Binds |
|---|---|---|---|---|---|---|---|---|---|---|
| Lead (Pb) | — | — | — | 200 | 200 | 200 | — | — | 200 | Mercosur |
| Inorganic arsenic (iAs) | — | — | — | — | 100 | — | — | — | 100 | Israel |
| Total arsenic (tAs) | — | — | — | — | 1000 | — | — | — | 1000 | Israel |
| Mercury, total (tHg) | — | — | — | — | 30 | — | — | — | 30 | Israel |
| Methylmercury (MeHg) | — | — | — | — | — | — | — | — | n/m³ | controlled |
| Cadmium (Cd) | 200 | 200 | — | 200 | 200 | 200 | 200 | — | 200 | EU |
| Hexavalent chromium (Cr-VI) | — | — | — | — | — | — | — | — | n/m³ | controlled |
| Nickel (Ni) | 6000 | — | — | — | — | — | — | 6000 | 6000 | EU |
| Tin (Sn) | — | — | — | — | — | — | — | — | n/m³ | controlled |
| Aluminium (Al) | — | — | — | — | — | — | — | — | control&sup4; | screened |
| Total chromium (Cr) | — | — | 1000 | — | — | — | — | — | 1000 | China |
All values µg/kg (ppb), as-sold basis. ² no government sets this analyte for this exact product form: the value is read across from the nearest government limit for an analogous product, or — where the Binds column reads occurrence or precautionary — taken from measured occurrence data or set as a precautionary near-neighbour value; the ratchet tightens it as surveillance warrants. ³ not material in this matrix: controlled by reflex speciation or packaging control, not a standalone number. &sup4; no sovereign maximum exists for this analyte in this product, but a credible exposure pathway does — it is screened on every lot under ALARA against the tightest analogous reference, not assigned an invented number.
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.
3 studies in the corpus measured total mercury in Soy Products (938 samples reported across those studies): Wu 2024, Hariono 2023, Yu 2023.
HMTc sets 30 ppb (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. Why total mercury is limited →
6 studies in the corpus measured cadmium in Soy Products (1153 samples reported across those studies): Zhang 2026, Zverina 2025, Jaudenes-Marrero 2024, Wu 2024, Yu 2023, Shindoh 2010.
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. Why cadmium is limited →
3 studies in the corpus measured nickel in Soy Products (405 samples reported across those studies): Zhang 2026, Jaudenes-Marrero 2024, Wu 2024.
HMTc sets 6 mg/kg (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. Why nickel is limited →
The corpus holds 1 measurement of aluminium in Soy Products (90 samples reported across those studies), which the determination below is tested against: Jaudenes-Marrero 2024.
HMTc sets no standalone aluminium limit for Soy Products. No credible sovereign government sets an aluminium contaminant maximum for plain legumes, pulses, peanuts, peanut butter, or soy products. Under the government-limit-only method HMTc publishes no standalone numeric Al limit for this matrix; naturally present or additive-derived aluminium remains a surveillance and formulation-control issue governed by the additive rules of the markets of sale. The analyte is controlled by Screen total Al by ICP-MS and document any aluminium-containing additive or processing-aid use; investigate elevated results and comply with all additive rules in markets of sale, not a standalone number. Why aluminium is limited →
Cite this standard
Pendergrass, K. “Soy products (soybeans, edamame, tofu, tempeh, soy flour, and other whole-soy foods).” In Heavy Metal Tested & Certified (HMTc) Legumes and Pulses standard, version 1.0. Institute of Contaminant Standards (ICS), 2026. DOI: registration pending.
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.