Plastics Introduce Hidden Metal Risks
Plastics and polymers are widely used in cannabis production vessels and containers. These materials are not typically associated with metal contamination of cannabinoids. However, they can contribute elemental contaminants to the final product.
Heavy metals in soil and fertilizer remain the most common source of trace-element contamination. Metals are taken up through the plant’s root system and enter extracted cannabinoids. Stainless steel vessels and equipment also serve as a secondary source of contamination.
Vaping cartridges present particular concerns due to metal components like coils and atomizers. These parts can leach metal particles into vaping liquids. This leaching occurs due to manufacturing defects or long-term storage of the devices.
Pharmaceutical Standards Highlight the Gap
The pharmaceutical industry well documents that plastic materials can contribute to elemental impurities. The United States Pharmacopeia has devoted several chapters to this specific issue. Drug products can chemically interact with associated packaging systems and plastic components.
USP Chapter <661.3> describes five model extraction methods for evaluating plastic suitability. These standardized conditions assess both organic and inorganic impurities. The plastic component is filled with a test solution or placed in a borosilicate flask.
Pharmaceutical manufacturers must establish that plastic components are suitable for their intended use. This is accomplished through a comprehensive risk-assessment approach. Materials are appropriately characterized, tested, and evaluated for safety.
Cannabis Lacks Similar Oversight
Cannabis consumer products do not receive the same attention regarding plastic impurities. The pharmaceutical industry places responsibility on manufacturers to test for extractable metals. This systematic approach is currently absent in the cannabis sector.
Plastic materials used in manufacturing can contain additives with potential elemental impurities. Raw materials and production intermediates may come into contact with these components. These interactions can introduce process-related impurities into the product.
The opportunity for interaction increases when plastic vessels are used in liquid storage systems. Cannabis manufacturers currently lack the standardized extraction procedures used in pharma. This gap leaves potential metal risks unaddressed in the production process.

