Who this standard is for
Four audiences read this page differently. Each has a route through it.
Read the Master Limit Table and the derivation. Every numeric claim traces to a source page on the independent literature index.
Read the Master Limit Table. The mark on a product means the brand tested at or below every value in it, in the product’s native basis.
Read the HMTc-limit column and the rationale tag. Each limit is set to the strictest applicable government maximum by lookup, in the native basis; for the Tier-1 toxics (Pb, Cd, iAs, MeHg) and for cells no government regulates, the program’s pooled occurrence distribution sets or tightens the value, never above the government maximum.
Read the rationale column and the firm/in-development split. Every published value carries its pooled figure, its native basis, and the reason for any gap with the pool.
Master Limit Table
All values in ppb, as sold. A firm limit renders only for an analyte that has cleared all five shipping gates; every other analyte shows its honest evidence state and no number. The pooled column shows the program’s occurrence figure for the analyte; the HMTc limit is the stricter of the applicable government maximum and, for Tier-1 toxics and cells no government regulates, that pooled figure, so the derivation stays re-derivable and the rationale tag names which bound. A brand meeting every firm value on a like-for-like basis qualifies for the mark for this subcategory.
| Analyte | Tier | HMTc limit | Pooled | Rationale | Status |
|---|---|---|---|---|---|
| Pb | Tier 1 | — | — | READY FOR REVIEW (regulatory cap applies); distinct_sources=2; sens_band=stable; classif… | in development |
| tAs | Tier 2 | — | — | — | not in scope |
| iAs | Tier 1 | — | — | — | not in scope |
| Cd | Tier 1 | — | — | READY FOR REVIEW; distinct_sources=2; sens_band=stable; classify=resolved/firm | in development |
| tHg | Tier 2 | — | — | — | not in scope |
| MeHg | Tier 1 | — | — | — | not in scope |
| Ni | Tier 2 | — | — | — | not in scope |
| Cr-VI | Tier 2 | — | — | — | not in scope |
| Sn | Tier 2 | — | — | — | not in scope |
| Al | Tier 2 | — | — | — | not in scope |
Published values round to the HMTc primary increment ladder: 1 · 2 · 3 · 5 · 10 · 15 · 20 · 25 · 50 · 100 · 200 · 500 · 1000 · 1300 · 1500 · 2000 · 5000 · 10000, so a brand has an unambiguous bin to test against.
No analyte in this subcategory has cleared all five shipping gates yet, so no firm limit is in force. This page reports the current evidence state honestly; it is not yet a published standard. See Program structure for how a subcategory reaches publication.
Analyte scope
This disclosure travels with the mark so a certified product is never silently uncontrolled on an analyte. The panel is Pb, tAs, iAs, Cd, tHg, MeHg, Ni, Cr-VI, Sn, Al.
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 Butter and ghee (317 samples reported across those studies): Hasan 2021, Starska 2011.
No firm HMTc limit is published for lead in Butter and ghee yet; the cell is in development pending the shipping gates. The strictest applicable government maximum level is 100 ppb (literature-baseline), which the certification limit will adopt. Why lead is limited →
1 study in the corpus measured total arsenic in Butter and ghee (256 samples reported across those studies): Hasan 2021.
No firm HMTc limit is published for total arsenic in Butter and ghee yet; the cell is in development pending the shipping gates. Why total arsenic is limited →
2 studies in the corpus measured cadmium in Butter and ghee (317 samples reported across those studies): Hasan 2021, Starska 2011.
No firm HMTc limit is published for cadmium in Butter and ghee yet; the cell is in development pending the shipping gates. Why cadmium is limited →
1 study in the corpus measured total mercury in Butter and ghee (3 samples reported across those studies): Pankiewicz 2012.
No firm HMTc limit is published for total mercury in Butter and ghee yet; the cell is in development pending the shipping gates. Why total mercury is limited →
Cite this standard
Pendergrass, K. (2026). Butter and ghee: HMTc standard. Institute of Contaminant Standards.
© 2026 Institute of Contaminant Standards / Heavy Metal Certified. All rights reserved.
The evidence each limit is applied to lives on the independent Heavy Metal Index; HMTc cites it one way and never the reverse. HMTc standards are living, versioned documents; this page reflects 2.2 (2026-06-09) and superseded versions remain at stable URLs so prior citations resolve. The threshold-setting methodology is described in Program structure.