# Heavy metals panel

> A heavy metals panel measures toxic elements, usually lead, arsenic, cadmium and mercury, in a cannabis sample, typically by ICP-MS, against regulatory action limits.

- Canonical: https://genetixbay.com/knowledge/glossary/heavy-metals-panel.html
- Also written: heavy metals test, heavy metal testing, metals panel, ICP-MS, lead arsenic cadmium mercury, heavy metals
- Glossary category: Lab testing · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

A heavy metals panel quantifies the toxic [trace elements](https://genetixbay.com/knowledge/glossary/micronutrient.md) most regulators require: lead (Pb), arsenic (As), cadmium (Cd) and mercury (Hg), sometimes with others such as chromium. The usual method digests the sample in acid and measures it by inductively coupled plasma mass spectrometry (ICP-MS), which detects elements at parts-per-billion levels.

## In practice

Cannabis takes up metals readily from its [root zone](https://genetixbay.com/knowledge/glossary/root-zone.md), which is why [hemp](https://genetixbay.com/knowledge/glossary/hemp.md) has been studied for cleaning contaminated soils. That same trait makes metals a real risk in flower. Sources include contaminated soil, some fertilisers and amendments, poor water and equipment. A [COA](https://genetixbay.com/knowledge/glossary/coa.md) reports each element in µg/g (ppm) or µg/kg (ppb) against action limits that vary by jurisdiction and product type; check local rules. If a crop fails, test inputs, not just the flower.

## Units and formula

µg/g = ppm; µg/kg = ppb. 0.5 µg/g lead = 500 µg/kg.

## Don't confuse with

- **Plant nutrients**: iron, [zinc](https://genetixbay.com/knowledge/glossary/zinc.md), [copper](https://genetixbay.com/knowledge/glossary/copper.md) and [manganese](https://genetixbay.com/knowledge/glossary/manganese.md) are essential micronutrients, not "heavy metals" in this regulatory sense, though they can be toxic in excess.
- **Pesticide panel**: organic chemical residues, a separate test.

## Related terms

[Pesticide panel](https://genetixbay.com/knowledge/glossary/pesticide-panel.md), [COA](https://genetixbay.com/knowledge/glossary/coa.md), [LOD](https://genetixbay.com/knowledge/glossary/lod.md), [Batch](https://genetixbay.com/knowledge/glossary/batch.md)

## Read more

- [Water quality for cannabis: RO vs tap, alkalinity, bicarbonates and chloramine](https://genetixbay.com/knowledge/ph-ec/water-quality.md)