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 Ingredient class — live microbials/probiotics 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.
Risk Flag
On the published occurrence literature to date, Ingredient class — live microbials/probiotics 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). Ingredient class — live microbials/probiotics: HMTc standard (Standard No. 10.83138/hmtc.std.16.supplements-probiotics). Institute of Contaminant Standards. https://doi.org/10.83138/hmtc.std.16.supplements-probiotics
© 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.