How limits are set
No government sets a heavy-metal maximum level for a dietary supplement that protects a child. The adult frameworks that exist — sovereign food-supplement limits (lead 1000–10000 µg/kg), USP <2232> elemental-contaminant PDEs computed for an adult consumer, California Proposition 65 warning doses — are written for a 60–70 kg adult. HMTc instead holds every supplement, adult- or child-labelled, to the strictest sovereign infant-and-child-food maximum level for each analyte, because children routinely consume adult supplements (gummies, protein powders, greens, melatonin drops) and body-weight-normalised exposure makes the child the binding safety case.
Every value on this page is therefore a child-protective read-across, disclosed as such: the anchor is a real sovereign infant-food limit, named in the derivation below, applied to supplements as a voluntary over-compliance. The laxer adult floor is disclosed on every analyte and never selects the number. Where no government sets an infant-and-child-food limit for an analyte — total and hexavalent chromium, methylmercury — no number is invented: the analyte is placed under mandatory control with reflex speciation.
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) | 10 | government read-across (AU/NZ) |
| Inorganic arsenic (iAs) | 10 | government read-across (EU) |
| Total arsenic (tAs) | 50 | government read-across (India) |
| Mercury, total (tHg) | 4 | government read-across (Israel) |
| Methylmercury (MeHg) | bounded | ≤ total tHg, measured every lot (see note) |
| Cadmium (Cd) | 5 | government read-across (EU) |
| Hexavalent chromium (Cr-VI) | bounded | ≤ total Cr, measured every lot (see note) |
| Nickel (Ni) | 100 | government read-across (EU) |
| Tin (Sn) | 5000 | government read-across (India) |
| Aluminium (Al) | 500 | government read-across (AU/NZ) |
| 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
No government regulates a dietary supplement to a child-safe heavy-metal level. Each HMTc limit for Oral solids: tablets/caplets is read across from the strictest sovereign infant-and-child-food maximum level for the analyte — the child anchor named below — and applied to all supplements as a voluntary over-compliance. The adult floor column discloses the laxer sovereign supplement limit, USP <2232> oral concentration, and California Prop 65 dose that HMTc declines to use. It is shown, and never selected.
| Analyte | Child-protective anchor | HMTc | Adult floor (disclosed, not used) | Basis |
|---|---|---|---|---|
| Lead (Pb) | AU/NZ — infant formula products | 10 | Thailand 1000–10000 · USP <2232> 500 · Prop 65 0.5 µg/day | child-protective read-across |
| Inorganic arsenic (iAs) | EU — infant formulae, follow-on formulae, food for special medical purposes intended for infants and young children, and young-child formulae placed on the market as liquid | 10 | USP <2232> 1500 | child-protective read-across |
| Total arsenic (tAs) | India — Infant Milk substitute and Infant foods | 50 | ASEAN 300–5000 | child-protective read-across |
| Mercury, total (tHg) | Israel — Infant and toddler formulas, ready-to-eat | 4 | GSO 100–500 · USP <2232> 1500 | child-protective read-across |
| Methylmercury (MeHg) | ≤ tHg | bounded | — | bounded by parent total |
| Cadmium (Cd) | EU — infant formulae, follow-on formulae, food for special medical purposes intended for infants and young children, and young-child formulae placed on the market as liquid and manufactured from cow's milk proteins or cow's milk protein hydrolysates | 5 | Thailand 300–1000 · USP <2232> 500 · Prop 65 4.1 µg/day | child-protective read-across |
| Hexavalent chromium (Cr-VI) | ≤ Cr | bounded | — | bounded by parent total |
| Nickel (Ni) | EU — infant/young-child formula, liquid | 100 | — | child-protective read-across |
| Tin (Sn) | India — Infant Milk substitute and Infant foods | 5000 | — | child-protective read-across |
| Aluminium (Al) | AU/NZ — infant formula, follow-on formula, and special medical purpose product for infants other than preterm-infant products | 500 | — | child-protective read-across |
| Total chromium (Cr) | China — infant/child food | 1000 | — | child-protective read-across |
Adult floor values in µg/kg unless marked. Supplement ML is the strictest–laxest sovereign food-supplement maximum on the register; USP <2232> is the oral permitted-daily-exposure concentration at a 10 g/day intake; Prop 65 is the California developmental safe-harbour dose. HMTc holds every supplement to the child anchor instead.
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 certified-market pool measured cadmium in Oral solids: tablets/caplets across 2 certified-market samples. The pooled distribution centres on a median of 19.3 mg/kg and reaches 25.3 mg/kg at the 95th percentile. Brzezinska-Rojek 2023.
HMTc sets 5 ppb by read-across: Child-protective read-across from the strictest sovereign infant-and-child-food cadmium maximum (EU infant formula, 5 µg/kg). Adult supplement floors run 300-1000 µg/kg; adult USP <2232> permits 5 µg/day (500 µg/kg at 10 g/day); California's developmental cadmium MADL is 4.1 µg/day. HMTc holds ALL supplements to 5 µg/kg. Basis disclosure: this EU anchor (source_id eu2023_cd_formula_cow_liquid_5) is set on a ready-to-feed liquid, as-consumed basis and is read across to the as-sold solid supplement WITHOUT a reconstitution adjustment. A reconstituted liquid formula is roughly 6-8x more dilute than the equivalent as-sold powder, so applying the liquid value directly to a solid is an intentional, disclosed over-strictness (the solid cell runs ~6-8x stricter than the equivalent as-sold powder ML), never an accidental wet/dry conflation; no serving-size conversion selects the limit. Why cadmium is limited →
1 study in the certified-market pool measured aluminium in Oral solids: tablets/caplets across 10 certified-market samples. The pooled distribution centres on a median of 8.1 mg/kg and reaches 20 mg/kg at the 95th percentile. Brzezinska-Rojek 2023.
HMTc sets 500 ppb by read-across: Child-protective read-across from the AU-NZ non-soy infant-formula aluminium maximum (500 µg/kg) — the only government aluminium ML for any food in any jurisdiction. No adult supplement aluminium ML exists and USP <2232> sets none. HMTc holds ALL supplements to 500 µg/kg. Why aluminium 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.
Aluminium
Grains and cereals, aluminium-based leavening agents (baking powder made with sodium aluminium sulfate or phosphate), and some tablet and capsule excipients carry high aluminium. No government sets an aluminium limit for solid infant food, so the standard holds these products to the strictest sovereign infant aluminium ceiling — the AU-NZ infant-formula limit — as a protective read-across, rather than to the only limit that names solid foods (an adult additive-residue allowance many times looser). Much of the excess comes from aluminium-based leavening, which a brand can reformulate away with aluminium-free baking powder.
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. (2026). Oral solids: tablets/caplets: HMTc standard (Standard No. 10.83138/hmtc.std.16.supplements-oral-solids-tablets). Institute of Contaminant Standards. https://doi.org/10.83138/hmtc.std.16.supplements-oral-solids-tablets
© 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.