How every number on this page is 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-consumed basis. 4 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.
| Analyte | Tier | HMTc limit | Binding basis |
|---|---|---|---|
| Lead (Pb) | Tier 1 | 200 | government read-across (Hong Kong) |
| Inorganic arsenic (iAs) | Tier 1 | 20 | government read-across (EU) |
| Total arsenic (tAs) | Tier 2 | control | mandatory control — no government ML; screened every lot (see note) |
| Mercury, total (tHg) | Tier 1 | control | mandatory control — no government ML; screened every lot (see note) |
| Methylmercury (MeHg) | Tier 1 | n/m | not material — controlled analyte (see note) |
| Cadmium (Cd) | Tier 1 | control | mandatory control — no government ML; screened every lot (see note) |
| Hexavalent chromium (Cr-VI) | Tier 2 | n/m | not material — controlled analyte (see note) |
| Nickel (Ni) | Tier 2 | 250 | government read-across (EU) |
| Tin (Sn) | Tier 2 | 100000 | strictest government ML (EU) |
| Aluminium (Al) | Tier 2 | control | mandatory control — no government ML; screened every lot (see note) |
| Total chromium (Cr) | Tier 2 | control | mandatory control — no government ML; screened every lot (see note) |
Tier 1 (Pb, iAs, Hg, MeHg, Cd) are zero-tolerance toxics with no established safe threshold. Tier 2 (tAs, Cr-VI, Ni, Sn, Al, Cr) carry a 150% transitional allowance under the program’s Status A–E framework.
Derivation — every government’s number, side by side
The full derivation for Kombucha, tea-based. Each row lists every government maximum level in force worldwide, converted to the as-consumed 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) | 200² | read-across |
| Inorganic arsenic (iAs) | 20² | read-across |
| 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) | n/m³ | controlled |
| Nickel (Ni) | 250² | read-across |
| Tin (Sn) | 100000 | EU |
| Aluminium (Al) | control&sup4; | screened |
| Total chromium (Cr) | control&sup4; | screened |
All values µg/kg (ppb), as-consumed 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: controlled by reflex speciation or packaging control, not a standalone number. &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.
1 study in the corpus measured lead in Kombucha (5 samples reported across those studies): Munilla-Garcia 2023.
HMTc sets 200 ppb by read-across: Hong Kong Cap 132V sets lead in Tea beverages made from Tea, Green, Black at 0.2 mg/kg = 200 ug/kg, with Note 11 scoping the cell to beverages that are, or are reconstituted to be, ready to drink. Kombucha is a ready-to-drink beverage made from tea, so this is the nearest applicable sovereign value and arguably a direct cell; it is recorded as a disclosed read-across because the instrument does not name the fermented form. Why lead is limited →
Cite this standard
Pendergrass, K. “Kombucha, tea-based.” In Heavy Metal Tested & Certified (HMTc) Beverages 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.