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 Cultivated mushrooms — common (button/Agaricus bisporus and other common farmed fungi)’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. 9 of 11 analytes carry a firm ceiling; the remaining 2 are toxic species bounded by their parent totals (species ≤ total, measured on every lot), so every analyte carries an enforceable ceiling. A brand meeting every value on a like-for-like basis qualifies for the mark.
| Analyte | HMTc limit | Binding basis |
|---|---|---|
| Lead (Pb) | 300 | strictest government ML (EU) |
| Inorganic arsenic (iAs) | 60 | strictest government ML (Israel) |
| Total arsenic (tAs) | 300 | strictest government ML (Mercosur) |
| Mercury, total (tHg) | 30 | strictest government ML (Israel) |
| Methylmercury (MeHg) | bounded | ≤ total tHg, measured every lot (see note) |
| Cadmium (Cd) | 50 | strictest government ML (EU) |
| Hexavalent chromium (Cr-VI) | bounded | ≤ total Cr, measured every lot (see note) |
| Nickel (Ni) | 400 | government read-across (EU) |
| Tin (Sn) | 250000 | government read-across (Singapore) |
| Aluminium (Al) | 100000 | government read-across (China) |
| Total chromium (Cr) | 1000 | government read-across (China) |
Every claim analyte is equal at the gate. A product is certified only when every analyte is at or below 100% of its published government floor or disclosed read-across; above the limit, on any metal, it is not certified and carries no mark.
Derivation
The full derivation for Cultivated mushrooms — common (button/Agaricus bisporus and other common farmed fungi). 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 | Mercosur | Israel | Morocco | Paraguay | Thailand | CH | CO | BA | Hong Kong | HMTc | Binds |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lead (Pb) | 300 | 300 | 300 | — | 300 | 300 | 300 | 300 | 300 | 300 | 300 | 300 | EU |
| Inorganic arsenic (iAs) | — | — | — | 60 | — | — | — | — | — | — | — | 60 | Israel |
| Total arsenic (tAs) | — | — | 300 | 1000 | — | 300 | — | — | — | — | — | 300 | Mercosur |
| Mercury, total (tHg) | — | — | — | 30 | — | — | — | — | — | — | — | 30 | Israel |
| Methylmercury (MeHg) | — | — | — | — | — | — | — | — | — | — | — | bounded&sup5; | species ≤ tHg |
| Cadmium (Cd) | 50 | — | 200 | — | 200 | 200 | — | 50 | 200 | 50 | 500 | 50 | EU |
| Hexavalent chromium (Cr-VI) | — | — | — | — | — | — | — | — | — | — | — | bounded&sup5; | species ≤ Cr |
| Nickel (Ni) | — | — | — | — | — | — | — | — | — | — | — | 400² | read-across |
| Tin (Sn) | — | — | — | — | — | — | — | — | — | — | — | 250000² | read-across |
| Aluminium (Al) | — | — | — | — | — | — | — | — | — | — | — | 100000² | read-across |
| Total chromium (Cr) | — | — | — | — | — | — | — | — | — | — | — | 1000² | read-across |
All values µg/kg (ppb), as-sold 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. &sup5; a toxic species governed by and bounded by its parent total (for example inorganic arsenic ≤ total arsenic): the species can never exceed the total, so the total ceiling is the species ceiling. The total metal is measured on every lot and the species is established at baseline; no separate species ceiling is published. On ongoing lots the species is speciated whenever the total exceeds its limit.
Risk Flag
On the published occurrence literature to date, Cultivated mushrooms — common (button/Agaricus bisporus and other common farmed fungi) 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.
Cite this standard
Pendergrass, K. (2026). Cultivated mushrooms — common (button/Agaricus bisporus and other common farmed fungi): HMTc standard (Standard No. 10.83138/hmtc.std.29.cultivated-mushrooms). Institute of Contaminant Standards. https://doi.org/10.83138/hmtc.std.29.cultivated-mushrooms
© 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.