Fertilizer and soil contain metals. Some of these metals are toxic and known as heavy metals. As the cannabis plant grows these heavy metals can enter the plant. This is why heavy metal screening is important.
Acceptable limits of heavy metals are measured in the range of parts per million (ppm) per gram. Check your state’s specific regulations to see the concentration levels for hazardous heavy metals such as Cadmium (Cd), Arsenic (As), Lead (Pb) and Mercury (Hg).
Inductively Coupled Plasma Mass Spectrometry Detector (ICP-MS) and Atomic Absorption Spectrophotometers (AAS) instruments are most often used for Cannabis heavy metal testing. Review your State Cannabis Regulations to see which instruments and tests are required.