Flour — wheat, corn, and other non-rice — HMTc Standard

How every number on this page is 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 Flour — wheat, corn, and other non-rice’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. 6 of 11 analytes carry a firm ceiling; the remainder are governed by mandatory control or reflex-speciation screening 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.

Tier 1 (Pb, iAs, Hg, MeHg, Cd) are zero-tolerance toxics with no established safe threshold. Tier 2 (tAs, Cr, Cr-VI, Ni, Sn, Al) carry a 150% transitional allowance under the program’s Status A–E framework. Inorganic arsenic (iAs) is the arsenic species that binds on rice: rice hyperaccumulates arsenic, and every government that regulates it does so by product form (milled 150, parboiled/husked/rice-flour 250, rice products 300, rice drinks 30). Non-rice cereals do not hyperaccumulate arsenic, so iAs is not-material there and total arsenic (tAs) carries the government cereal ceiling instead. Mercury is limited as total mercury (tHg); methylmercury (MeHg), which no government regulates in grain, is bounded by the total-mercury ceiling. Hexavalent chromium (Cr-VI) is controlled by reflex speciation on total chromium, not an invented number. Tin (Sn) is material only for canned product, which routes to the canned-goods category. Aluminium (Al) has no government grain maximum in any jurisdiction.

Derivation — every government’s number, side by side

The full derivation for Flour — wheat, corn, and other non-rice. 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.

All values µg/kg (ppb), as-sold basis. ² no government sets this analyte for this exact product form: the value is read across from the nearest government limit for an analogous product, or — where the Binds column reads occurrence or precautionary — taken from measured occurrence data or set as a precautionary near-neighbour value; the ratchet tightens it as surveillance warrants. ³ not material in this matrix: controlled by reflex speciation or packaging control, not a standalone number.

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.

Cite this standard

Pendergrass, K. “Flour — wheat, corn, and other non-rice.” In Heavy Metal Tested & Certified (HMTc) Grains, Cereals, and Rice Products 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.