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 Dry pet food (complete & balanced kibble)’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 | Tier | HMTc limit | Binding basis |
|---|---|---|---|
| Lead (Pb) | Tier 1 | 20 | government read-across (Hong Kong) |
| Cadmium (Cd) | Tier 1 | 40 | government read-across (EU) |
| Total arsenic (tAs) | Tier 2 | 100 | government read-across (Paraguay) |
| Inorganic arsenic (iAs) | Tier 1 | 100 | government read-across (Israel) |
| Mercury, total (tHg) | Tier 1 | 20 | government read-across (Hong Kong) |
| Methylmercury (MeHg) | Tier 1 | bounded | ≤ total tHg, measured every lot (see note) |
| Nickel (Ni) | Tier 2 | 800 | government read-across (EU) |
| Tin (Sn) | Tier 2 | 250000 | government read-across (Singapore) |
| Aluminium (Al) | Tier 2 | 100000 | government read-across (China) |
| Total chromium (Cr) | Tier 2 | 500 | government read-across (Hong Kong) |
| Hexavalent chromium (Cr-VI) | Tier 2 | bounded | ≤ total Cr, measured every lot (see note) |
Tier 1 (Pb, iAs, Hg, MeHg, Cd) are zero-tolerance toxics with no established safe threshold. Tier 2 (tAs, Ni, Sn, Al, Cr, Cr-VI) carry a 150% transitional allowance under the program’s Status A–E framework. Pet food is legally feed; HMTc voluntarily certifies each analyte to the strictest human-food sovereign maximum for the nearest analog, with the laxer feed-law floor disclosed for contrast. Inorganic arsenic and hexavalent chromium are reflex-speciation screens bounded by total arsenic and total chromium; methylmercury is bounded by total mercury. Nickel, tin and aluminium carry disclosed read-across limits where no government sets a general pet-food maximum.
Derivation
The full derivation for Dry pet food (complete & balanced kibble). 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 | AU/NZ | GSO | India | Mercosur | Israel | Morocco | Panama | Philippines | Paraguay | Singapore | Thailand | Vietnam | Hong Kong | CU | CO | HMTc | Binds |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lead (Pb) | 100 | 200 | 100 | 100 | 100 | 100 | 900 | 100 | 100 | 100 | — | 100 | 100 | 20 | 100 | 200 | 20² | read-across |
| Cadmium (Cd) | 40 | 100 | 100 | 100 | 100 | 100 | 100 | — | 100 | 100 | — | 100 | 100 | 100 | 100 | 100 | 40² | read-across |
| Total arsenic (tAs) | — | 1000 | — | — | 100 | 1000 | — | — | — | 100 | — | — | — | 500 | — | — | 100² | read-across |
| Inorganic arsenic (iAs) | 150 | — | 200 | — | — | 100 | — | — | 200 | — | 200 | 200 | — | 200 | — | — | 100² | read-across |
| Mercury, total (tHg) | — | — | 1000 | — | — | 30 | — | — | — | — | — | — | — | 20 | — | — | 20² | read-across |
| Methylmercury (MeHg) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | bounded&sup5; | species ≤ tHg |
| Nickel (Ni) | 800 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 800² | read-across |
| Tin (Sn) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 250000² | read-across |
| Aluminium (Al) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 100000² | read-across |
| Total chromium (Cr) | — | — | — | — | — | — | — | — | — | — | — | — | — | 500 | — | — | 500² | read-across |
| Hexavalent chromium (Cr-VI) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | bounded&sup5; | species ≤ Cr |
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.
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 certified-market pool measured lead in Complete & balanced dry across 399 certified-market samples. The pooled distribution centres on a median of 5.4 mg/kg and reaches 81.2 mg/kg at the 95th percentile, with a measured maximum of 270 mg/kg. Haydous 2025, Pain 2023, Kim 2018.
HMTc sets 20 ppb by read-across: Human-grade read-across: the strictest human-food sovereign maximum level for the the plant-carbohydrate fraction of a complete diet: cereals, grains, pulses, and starchy tubers (adult/general human food, as sold) (HK, 20 µg/kg, as sold basis). Pet food is legally governed by feed law (feed floor 5000 µg/kg); HMTc voluntarily certifies to the stricter human-food limit. Why lead is limited →
2 studies in the certified-market pool measured cadmium in Complete & balanced dry across 257 certified-market samples. The pooled distribution centres on a median of 63 ppb and reaches 3.3 mg/kg at the 95th percentile. Haydous 2025, Kim 2018.
HMTc sets 40 ppb by read-across: Human-grade read-across: the strictest human-food sovereign maximum level for the the plant-carbohydrate fraction of a complete diet: cereals, grains, pulses, and starchy tubers (adult/general human food, as sold) (EU, 40 µg/kg, as sold basis). Pet food is legally governed by feed law (feed floor 2000 µg/kg); HMTc voluntarily certifies to the stricter human-food limit. Why cadmium is limited →
1 study in the certified-market pool measured total arsenic in Complete & balanced dry across 392 certified-market samples. The pooled distribution centres on a median of 100 ppb and reaches 762 ppb at the 95th percentile. Haydous 2025.
HMTc sets 100 ppb by read-across: Human-grade read-across: the strictest human-food sovereign maximum level for the the plant-carbohydrate fraction of a complete diet: cereals, grains, pulses, and starchy tubers (adult/general human food, as sold) (PY, 100 µg/kg, as sold basis). Pet food is legally governed by feed law (feed floor 2000 µg/kg); HMTc voluntarily certifies to the stricter human-food limit. Why total arsenic is limited →
1 study in the certified-market pool measured total mercury in Complete & balanced dry across 196 certified-market samples. The pooled distribution centres on a median of 1.3 mg/kg and reaches 1.3 mg/kg at the 95th percentile. Haydous 2025.
HMTc sets 20 ppb by read-across: Human-grade read-across: the strictest human-food sovereign maximum level for the the plant-carbohydrate fraction of a complete diet: cereals, grains, pulses, and starchy tubers (adult/general human food, as sold) (HK, 20 µg/kg, as sold basis). Pet food is legally governed by feed law (feed floor 300 µg/kg); HMTc voluntarily certifies to the stricter human-food limit. Why total mercury is limited →
Risk Flag
Where certification is demanding for this subcategory, and why. These 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.
Lead
Lead is taken up from soil and can enter through adulteration; grains and rice, protein and collagen powders, spices, root and tuber vegetables, and some botanicals are common carriers.
Mercury
Large and predatory fish and other marine ingredients accumulate methylmercury up the food chain.
Cadmium
Cocoa, leafy greens, sunflower and other seeds, organ meats, shellfish, seaweed, and some root vegetables concentrate cadmium from soil and seawater.
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.
Cite this standard
Pendergrass, K. “Dry pet food (complete & balanced kibble).” In Heavy Metal Tested & Certified (HMTc) Pet Foods 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.