How limits are set
A composite food has no contaminant maximum level of its own — no government sets a heavy-metal ML for 'bone broth' or 'prepared meal.' The HMTc limit for each analyte is therefore a disclosed read-across from the strictest maximum level a credible government sets for the product's principal components, converted to the as-consumed basis. Credible regulators are the EU, Codex, US FDA, WHO/JECFA, FSANZ, Health Canada, the UK, and — for the terrestrial-animal-meat commodities that anchor an animal-bone stock — Hong Kong (Cap 132V). Occurrence never sets a value.
Bone broth is a long-simmered animal-bone and connective-tissue stock. Bone is the body's principal lead reservoir, and lead partitions from bone into the broth during prolonged, often acidulated simmering, so lead is the priority analyte and reads across the strictest credible animal-meat lead ML (FSANZ, 100 µg/kg) rather than a generic stock value; cadmium reads across the meat ML (EU, 50). Total mercury reads across the Hong Kong Cap 132V meat-of-animal mercury ML (50 µg/kg): terrestrial meat is not a mercury-bioaccumulation matrix, but a sovereign meat ML exists, so the cell is a disclosed read-across rather than an unbounded screen.
Where no credible regulator sets a component ML (nickel, tin, aluminium, total chromium) the analyte is held under mandatory control; the species cells (inorganic arsenic, methylmercury, hexavalent chromium) are substantiated not-material determinations bounded by their measured total. A fish-derived bone broth additionally inherits the Category 6 seafood ceilings.
Master Limit Table
All values in ppb (µg/kg), as-consumed basis. 6 of 11 analytes carry a firm ceiling; the remaining 4 are governed by mandatory control or the total-metal screen 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 | HMTc limit | Binding basis |
|---|---|---|
| Lead (Pb) | 20 | government read-across (Hong Kong) |
| Cadmium (Cd) | 40 | government read-across (EU) |
| Total arsenic (tAs) | 500 | government read-across (Hong Kong) |
| Inorganic arsenic (iAs) | 50 | government read-across (EU) |
| Mercury, total (tHg) | 10 | government read-across (Hong Kong) |
| Methylmercury (MeHg) | control | mandatory control — no government ML; screened every lot (see note) |
| Nickel (Ni) | 400 | government read-across (EU) |
| Tin (Sn) | control | mandatory control — no government ML; screened every lot (see note) |
| Aluminium (Al) | control | mandatory control — no government ML; screened every lot (see note) |
| Total chromium (Cr) | screen | screening ceiling — Cr(VI) is the binding health control (see note) |
| Hexavalent chromium (Cr-VI) | n/m | not material — controlled analyte (see note) |
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
For Mixed and prepared meals (frozen dinners, boxed meals, ready-to-eat), each HMTc limit is the strictest maximum level any credible government sets for the product, named in the Binding column with the count of jurisdictions that concur at that value. Where no government regulates the analyte, the cell is a mandatory control or a not-material determination, never an invented number.
| Analyte | HMTc | Binding | Basis |
|---|---|---|---|
| Lead (Pb) | 20 | Hong Kong | disclosed read-across |
| Cadmium (Cd) | 40 | EU | disclosed read-across |
| Total arsenic (tAs) | 500 | Hong Kong | disclosed read-across |
| Inorganic arsenic (iAs) | 50 | EU | disclosed read-across |
| Mercury, total (tHg) | 10 | Hong Kong | disclosed read-across |
| Methylmercury (MeHg) | control | screened every lot | mandatory control — no government ML |
| Nickel (Ni) | 400 | EU | disclosed read-across |
| Tin (Sn) | control | screened every lot | mandatory control — no government ML |
| Aluminium (Al) | control | screened every lot | mandatory control — no government ML |
| Total chromium (Cr) | screen | Cr(VI) binds | screening ceiling (undefined action level 500 µg/kg — non-protective for total Cr); any quantifiable Cr(VI) fails |
| Hexavalent chromium (Cr-VI) | n/m | ≤ Cr | not material in this matrix |
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.
1 study in the corpus measured lead in Mixed Meals / Prepared Foods (480 samples reported across those studies): Hwang 2022.
HMTc sets 20 ppb by read-across: the dairy component binds at 20 ug/kg (Hong Kong Cap. 132V, Milk and Secondary milk products), stricter than the fruiting-vegetable and preserved-tomato rows (50 each) that bound in v1.1 and stricter than the root/tuber vegetable (100), meat (100), cereal (200) and fish (300) components. Tightened from 100 to 50 in v1.1 on the Cap. 132V admission, and from 50 to 20 in v1.2 on the dairy ruling. Why lead is limited →
1 study in the corpus measured cadmium in Mixed Meals / Prepared Foods (480 samples reported across those studies): Hwang 2022.
HMTc sets 40 ppb by read-across: the pulse/legume component (EU 40 ug/kg) is the binding cadmium component; a prepared meal with a bean/lentil/soy component is held to the strictest applicable component ceiling. Why cadmium is limited →
1 study in the corpus measured total arsenic in Mixed Meals / Prepared Foods (480 samples reported across those studies): Hwang 2022.
HMTc sets 500 ppb by read-across: Cap. 132V sets a total-arsenic ML of 500 ug/kg for vegetables, for cereals other than rice, for meat of animal and for meat of poultry, which covers every principal component of a mixed meal and is stricter than the FSANZ cereal-grain ML (1000) that v1.0 selected. Total arsenic is published as a protective sovereign maximum level, not as a screen; the health-relevant inorganic fraction is separately and more strictly controlled on the iAs cell at 50 ug/kg. Why total arsenic is limited →
Risk Flag
On the published occurrence literature to date, Mixed and prepared meals (frozen dinners, boxed meals, ready-to-eat) 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). Mixed and prepared meals (frozen dinners, boxed meals, ready-to-eat): HMTc standard. Institute of Contaminant Standards.
© 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.