Pharmaceutical Standards Address Plastic Contamination
The United States Pharmacopeia has developed general chapters to cover the quality and suitability of plastic materials used in pharmaceutical applications. These standards address how drug products can chemically interact with associated packaging systems and plastic components. The interactions must not adversely affect the suitability of the drug product or the packaging system.
Patient and consumer safety remain the primary focus of these regulatory guidelines.
Plastic materials used in manufacturing equipment can potentially contribute to elemental contamination of drug products. The USP has devoted several specific chapters to this critical issue. Manufacturers are responsible for establishing that plastic components are suitable for their intended use.
This responsibility is accomplished through a comprehensive risk-assessment approach.
Materials must be appropriately characterized, tested, and evaluated during the manufacturing process. The question is not simply what plastic is being used in the facility. The more important question is what can potentially come out of that plastic and enter the product.
This distinction drives the testing protocols required by the industry.
Standardized Extraction Methods Define Testing
Pharmaceutical manufacturing uses a wide variety of plastic materials and exposes them to many different conditions. There is no single extraction procedure that perfectly represents every manufacturing situation. It would be impractical to impose a substantial number of extraction conditions on every manufacturer.
The pharmaceutical approach therefore uses a standardized set of extraction conditions.
These conditions are designed to assess both organic and inorganic impurities in the final product. USP Chapter <661.3> describes five model extraction methods for this purpose. The methods are shown in Table 1 of the relevant documentation.
For the assessment of extractable metals, the plastic component is filled with the test solution. Alternatively, an appropriate amount of plastic is placed into a high-purity borosilicate flask. The flask contains the test solution for the duration of the test.
This procedure allows for precise measurement of potential leaching.
Cannabis Industry Faces Similar Risks
Plastics and polymers are widely used in the manufacture of cannabis and hemp consumer products. These materials include vessels, containers, bottles, bags, transfer lines, carts, and pods. They are not typically associated with metal contamination of the cannabinoids being produced.
However, the pharmaceutical industry takes this potential risk very seriously.
It is well documented that plastic materials can contribute to elemental contamination of drug products. The United States Pharmacopeia has addressed this issue in several dedicated chapters. If metal impurities in plastic materials are serious for pharmaceuticals, the same attention is needed in cannabis.
The current lack of focus in the cannabis sector is a notable gap.
Every stage of the production process could potentially contribute elemental contaminants. This includes cultivation, extraction processing, manufacturing, packaging, and delivery. The evidence in the public domain indicates this could be an issue for cannabis manufacturers.
Adopting pharmaceutical standards offers a clear path to solving this problem.

