How limits are set
Category 5 carries two native bases and the compiler is configured never to mix them. A ready-to-drink beverage is certified in the as-consumed liquid basis at single strength, and a concentrate is assessed as reconstituted to single strength, which is the basis EU 2023/915 and Codex CXS 193 already write into their juice cells and Hong Kong Cap 132V Note 11 writes into its beverage entries.
A dry leaf, dry botanical, roasted bean or beverage powder is certified in the as-sold dry-commodity basis, because that is the article the applicant packages and the lot the auditor samples. No brewing, extraction, dilution or reconstitution factor is invented in either direction: the tea-leaf lead maximum level is never applied to a brewed cup, and a ready-to-drink beverage maximum level is never applied to a dry leaf.
Where a government instrument writes the product-form split itself, HMTc preserves it rather than collapsing it: Hong Kong Cap 132V sets Tea, Green, Black at 5000 ug/kg as sold against tea beverages made from it at 200 ug/kg as consumed, and coffee beans at 500 ug/kg as sold against coffee beverages at 200 ug/kg as consumed.
Two consequences of the method are disclosed rather than engineered away. The rice-based drink row is LOOSER on inorganic arsenic (30 ug/kg, EU 2023/915 section 3.4.1.6) than the juice rows (20 ug/kg, and 10 ug/kg for apple-containing juice), because the EU assessed that exact commodity and set that exact number. And several formulated-beverage rows carry a lead ceiling of 200 ug/kg because Hong Kong Cap 132V is the only credible sovereign that regulates those forms at all, while the flavoured-water row carries 5 ug/kg because the packaged-drinking-water quality standards do reach a product that is water plus flavour.
Those spreads are applicability judgements, each recorded on the face of the cell, and only the endogenous Standards Ratchet in Governance Policy section 12 may lower any of them.
Master Limit Table
All values in ppb (µg/kg), as-sold basis. 1 of 11 analytes carry a firm ceiling; the remaining 10 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) | 5000 | strictest government ML (Hong Kong) |
| Inorganic arsenic (iAs) | control | mandatory control — no government ML; screened every lot (see note) |
| Total arsenic (tAs) | control | mandatory control — no government ML; screened every lot (see note) |
| Mercury, total (tHg) | control | mandatory control — no government ML; screened every lot (see note) |
| Methylmercury (MeHg) | n/m | not material — controlled analyte (see note) |
| Cadmium (Cd) | control | mandatory control — no government ML; screened every lot (see note) |
| Hexavalent chromium (Cr-VI) | control | mandatory control — no government ML; screened every lot (see note) |
| Nickel (Ni) | control | mandatory control — no government ML; screened every lot (see note) |
| 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) | control | mandatory control — no government ML; screened every lot (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
The full derivation for Matcha. 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 | HMTc | Binds |
|---|---|---|
| Lead (Pb) | 5000 | Hong Kong |
| Inorganic arsenic (iAs) | control&sup4; | screened |
| Total arsenic (tAs) | control&sup4; | screened |
| Mercury, total (tHg) | control&sup4; | screened |
| Methylmercury (MeHg) | n/m³ | controlled |
| Cadmium (Cd) | control&sup4; | screened |
| Hexavalent chromium (Cr-VI) | control&sup4; | screened |
| Nickel (Ni) | control&sup4; | screened |
| Tin (Sn) | control&sup4; | screened |
| Aluminium (Al) | control&sup4; | screened |
| Total chromium (Cr) | control&sup4; | screened |
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. &sup4; no sovereign maximum exists for this analyte in this product, but a credible exposure pathway does — it is screened on every lot under ALARA against the tightest analogous reference, not assigned an invented 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.
2 studies in the corpus measured lead in Matcha (188 samples reported across those studies): Szymczykowska 2026, Masri 2025.
HMTc sets 5 mg/kg (regulatory-alignment): the strictest applicable government maximum level for this product form, adopted under Method v2.0 as the default certification standard. Why lead is limited →
The corpus holds 1 measurement of cadmium in Matcha (186 samples reported across those studies), which the determination below is tested against: Masri 2025.
HMTc sets no standalone cadmium limit for Matcha. No credible sovereign sets a cadmium maximum level for matcha powder. No credible sovereign sets a cadmium maximum level for tea in any form. As with lead, the whole-leaf ingestion route makes this a live cell rather than a formality, and the absence of a sovereign ceiling is disclosed rather than filled. No near-neighbour read-across is supportable, so the fail-safe disposition is a control: cadmium testing is mandatory on every certified lot and no ceiling is invented from occurrence data. The analyte is controlled by Cadmium by ICP-MS on every certified lot, reported on the certificate. A result above 10 ug/kg in a ready-to-drink form, or above 100 ug/kg in a dry form, escalates to an ingredient-origin and process-water investigation and is a Standards Ratchet surveillance input under Governance Policy section 12, not a standalone number. Why cadmium is limited →
Risk Flag
On the published occurrence literature to date, Matcha 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). Matcha: 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.