Heavy Metals

Heavy metals can enter cannabis through contaminated soil, water sources, fertilizers, and even grow equipment. Cannabis plants grown in industrial areas or on reclaimed land may contain elevated heavy metal levels. Some hydroponic nutrients contain trace metals, and poorly regulated growing inputs can introduce contaminants. Even post-harvest, metal exposure can occur through processing equipment or contaminated packaging materials.

All regulated cannabis markets require heavy metal testing as part of mandatory safety screening. The four metals typically tested are lead, arsenic, mercury, and cadmium, with action limits measured in parts per million or parts per billion. Products that exceed these limits cannot be legally sold. For consumers, the best protection is purchasing from licensed dispensaries where testing is required. Reading the certificate of analysis confirms that a product has passed heavy metal screening. Organic cultivation practices and clean water sources help minimize contamination at the growing level.