Heavy metals panel

Hemp is a bioaccumulator. Its roots draw metals out of soil efficiently enough that the plant has been used to clean contaminated land, which is good for remediation and bad for a crop grown for extraction. Metals in the biomass concentrate further when cannabinoids are extracted.

The standard panel covers arsenic, cadmium, lead and mercury. Some states add chromium, nickel or others. Laboratories digest the sample in acid and analyze it by inductively coupled plasma mass spectrometry, which a 2026 review identifies as the method of choice for trace metals in cannabis matrices (Cannabis Cannabinoid Res 2026). Results are reported in parts per million or micrograms per gram.

Limits are not federal. A 2022 comparison of state cannabis regulations found that states set their own analyte lists and thresholds, so a batch that passes in one state can fail in another (Jameson 2022). Hemp sold outside a state cannabis program often has no mandatory limit at all, which leaves testing to the brand.

A credible certificate of analysis prints each metal, its result, the limit applied and the detection limit. Testing the finished product rather than only the raw extract also catches metals introduced by carrier oils, flavorings or packaging.