How every number on this page is set
TWO CATEGORY RULES govern every row. (1) THE MATERIAL-FAMILY RULE: a row's published ceiling is anchored only where a sovereign instrument governs element migration into food from that row's PRINCIPAL food-contact material family. Polymer surfaces anchor EU 10/2011 Annex II directly, or by disclosed read-across where the instrument expressly excludes the polymer (silicone under Art. 2(2)(c), ion-exchange resin under Art. 2(2)(a)) or does not reach it (cured liquid-applied coatings, paper and board, wood). Metal, alloy, ceramic-glaze, vitreous-enamel and glass surfaces have no sovereign migration ceiling in the register, so those rows are controls with mandatory testing and no invented number. (2) THE COMPONENT RULE: every food-contact COMPONENT of an article is held to the regime of its own material family, and where a component's family has no sovereign ceiling that component is under control. A row's published cells state the ceiling for its principal food-contact material; the component plan names the other components, the regime each falls under, and which component is expected to bind. A result from a non-binding component does not represent the article: a can body wall does not represent its seam, a vacuum bottle wall does not represent its base-plug solder, a plain tumbler does not represent a decorated one, a blender jar does not represent its blade assembly, and a cold reservoir does not represent a post-descaling draw.
Master Limit Table
All values in ppb (µg/kg), as-sold basis. 0 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 | control | mandatory control — no government ML; screened every lot (see note) |
| Inorganic arsenic (iAs) | Tier 1 | control | mandatory control — no government ML; screened every lot (see note) |
| 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 | control | mandatory control — no government ML; screened every lot (see note) |
| Cadmium (Cd) | Tier 1 | control | mandatory control — no government ML; screened every lot (see note) |
| Hexavalent chromium (Cr-VI) | Tier 2 | control | mandatory control — no government ML; screened every lot (see note) |
| Nickel (Ni) | Tier 2 | control | mandatory control — no government ML; screened every lot (see note) |
| Tin (Sn) | Tier 2 | control | mandatory control — no government ML; screened every lot (see note) |
| 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 Water filters. 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) | control&sup4; | screened |
| Inorganic arsenic (iAs) | control&sup4; | screened |
| Total arsenic (tAs) | control&sup4; | screened |
| Mercury, total (tHg) | control&sup4; | screened |
| Methylmercury (MeHg) | control&sup4; | screened |
| 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: 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.
The corpus holds 1 measurement of lead in Water filters (146 samples reported across those studies), which the determination below is tested against: Decharat 2020.
HMTc sets no standalone lead limit for Water filters. A drinking-water treatment device is an intervention whose purpose is to REMOVE metals, so the certification question is not whether the effluent meets a food limit but whether the device itself contributes any element to the water it treats. No credible sovereign sets a release ceiling for a treatment device or its media: the EU regulates materials in contact with water intended for human consumption through the Art. 11 hygiene-requirement and positive-list route of Directive (EU) 2020/2184 rather than through element release values, the US route is the SDWA lead-free content definition plus NSF/ANSI 61 conformity, and neither is a sovereign element release ceiling in this register. Regulation (EU) 10/2011 does not reach the media at all: Art. 2(2)(a) expressly excludes ion exchange resins from its scope. The cell is therefore a control with mandatory net-contribution testing against a matched influent blank, and the sovereign drinking-water parametric value is disclosed as a companion obligation in the WATER basis, never republished as a device release ceiling. Lead is the element a filter is most often bought to remove, and it is simultaneously a possible device contribution from leaded brass fittings, bronze bodies and soldered joints in the wetted path. Both directions are tested: net contribution against a matched influent blank, and removal performance against the challenge influent. The sovereign drinking-water parametric value disclosed as this cell's companion is a limit on the WATER as delivered; it is not the device's release ceiling and is not published as one. The two mandatory determinations on this row are net device contribution against a matched influent blank and reduction performance at end of rated life; either one alone misrepresents the device. The analyte is controlled by Device-effluent extraction testing on the conditioned device: influent of defined composition passed through the device at rated flow, effluent sampled at first draw, after the manufacturer's conditioning volume, and at rated capacity, with ICP-MS determination of each element in the effluent and comparison against the matched influent blank so that any net contribution by the device is resolved separately from what the device removes, not a standalone number. Why lead is limited →
The corpus holds 1 measurement of inorganic arsenic in Water filters (622 samples reported across those studies), which the determination below is tested against: Abuawad 2023.
HMTc sets no standalone inorganic arsenic limit for Water filters. A drinking-water treatment device is an intervention whose purpose is to REMOVE metals, so the certification question is not whether the effluent meets a food limit but whether the device itself contributes any element to the water it treats. No credible sovereign sets a release ceiling for a treatment device or its media: the EU regulates materials in contact with water intended for human consumption through the Art. 11 hygiene-requirement and positive-list route of Directive (EU) 2020/2184 rather than through element release values, the US route is the SDWA lead-free content definition plus NSF/ANSI 61 conformity, and neither is a sovereign element release ceiling in this register. Regulation (EU) 10/2011 does not reach the media at all: Art. 2(2)(a) expressly excludes ion exchange resins from its scope. The cell is therefore a control with mandatory net-contribution testing against a matched influent blank, and the sovereign drinking-water parametric value is disclosed as a companion obligation in the WATER basis, never republished as a device release ceiling. Inorganic arsenic is the species that matters in water and is essentially the whole of the arsenic present, so it is determined in its own right rather than bounded: this row's total-arsenic cell is itself a control with no sovereign device ceiling, so no published parent could bound the species. The US EPA arsenic maximum contaminant level disclosed as this cell's companion is a WATER-basis limit on the treated supply. The two mandatory determinations on this row are net device contribution against a matched influent blank and reduction performance at end of rated life; either one alone misrepresents the device. The analyte is controlled by Device-effluent extraction testing on the conditioned device: influent of defined composition passed through the device at rated flow, effluent sampled at first draw, after the manufacturer's conditioning volume, and at rated capacity, with ICP-MS determination of each element in the effluent and comparison against the matched influent blank so that any net contribution by the device is resolved separately from what the device removes, not a standalone number. Why inorganic arsenic is limited →
The corpus holds 1 measurement of total arsenic in Water filters (622 samples reported across those studies), which the determination below is tested against: Abuawad 2023.
HMTc sets no standalone total arsenic limit for Water filters. A drinking-water treatment device is an intervention whose purpose is to REMOVE metals, so the certification question is not whether the effluent meets a food limit but whether the device itself contributes any element to the water it treats. No credible sovereign sets a release ceiling for a treatment device or its media: the EU regulates materials in contact with water intended for human consumption through the Art. 11 hygiene-requirement and positive-list route of Directive (EU) 2020/2184 rather than through element release values, the US route is the SDWA lead-free content definition plus NSF/ANSI 61 conformity, and neither is a sovereign element release ceiling in this register. Regulation (EU) 10/2011 does not reach the media at all: Art. 2(2)(a) expressly excludes ion exchange resins from its scope. The cell is therefore a control with mandatory net-contribution testing against a matched influent blank, and the sovereign drinking-water parametric value is disclosed as a companion obligation in the WATER basis, never republished as a device release ceiling. Arsenic is a principal reduction target for point-of-use devices and an impurity route in copper-alloy wetted parts. Determined as the total element. The two mandatory determinations on this row are net device contribution against a matched influent blank and reduction performance at end of rated life; either one alone misrepresents the device. The analyte is controlled by Device-effluent extraction testing on the conditioned device: influent of defined composition passed through the device at rated flow, effluent sampled at first draw, after the manufacturer's conditioning volume, and at rated capacity, with ICP-MS determination of each element in the effluent and comparison against the matched influent blank so that any net contribution by the device is resolved separately from what the device removes, not a standalone number. Why total arsenic is limited →
The corpus holds 1 measurement of cadmium in Water filters (146 samples reported across those studies), which the determination below is tested against: Decharat 2020.
HMTc sets no standalone cadmium limit for Water filters. A drinking-water treatment device is an intervention whose purpose is to REMOVE metals, so the certification question is not whether the effluent meets a food limit but whether the device itself contributes any element to the water it treats. No credible sovereign sets a release ceiling for a treatment device or its media: the EU regulates materials in contact with water intended for human consumption through the Art. 11 hygiene-requirement and positive-list route of Directive (EU) 2020/2184 rather than through element release values, the US route is the SDWA lead-free content definition plus NSF/ANSI 61 conformity, and neither is a sovereign element release ceiling in this register. Regulation (EU) 10/2011 does not reach the media at all: Art. 2(2)(a) expressly excludes ion exchange resins from its scope. The cell is therefore a control with mandatory net-contribution testing against a matched influent blank, and the sovereign drinking-water parametric value is disclosed as a companion obligation in the WATER basis, never republished as a device release ceiling. Cadmium can be contributed by cadmium-plated or cadmium-brazed wetted components and is a target of reduction claims. The two mandatory determinations on this row are net device contribution against a matched influent blank and reduction performance at end of rated life; either one alone misrepresents the device. The analyte is controlled by Device-effluent extraction testing on the conditioned device: influent of defined composition passed through the device at rated flow, effluent sampled at first draw, after the manufacturer's conditioning volume, and at rated capacity, with ICP-MS determination of each element in the effluent and comparison against the matched influent blank so that any net contribution by the device is resolved separately from what the device removes, not a standalone number. Why cadmium is limited →
Cite this standard
Pendergrass, K. “Water filters.” In Heavy Metal Tested & Certified (HMTc) Food-Contact Consumer Goods and Kitchenware 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.