The Challenges of Measuring Heavy Metal Contaminants in Cannabis Vaping Aerosols

The recent announcement by the state of Colorado that all cannabis concentrates in electronic cannabis delivery systems (ECDS) must be characterized for a suite of elemental contaminants in the emitted aerosol by January 2022 has stimulated a great deal of interest, since it was first reported that many of these vaping devices were corroding internal metallic components due to the acid pH of the cannabis extracts and diluent oils being used. Researchers were finding elements such as iron, chromium, nickel, aluminum, zinc and lead in the vaping liquid, which were derived from the coils, atomizers, tanks, battery terminals and mouthpieces, etc, made from a variety of metallic components inside the vaping devices such as stainless steel, brass, nichrome, kanthal and other metal-based materials. 

This white paper examines the fundamentals of vaping and in particular the process of converting a liquid into an aerosol and highlights the challenges of monitoring elemental contaminants in the vaping aerosol as opposed to the vaping liquid. In addition, it will focus on the difficulties associated with trapping and collecting the aerosol without contaminating the sample, and how best to validate the procedure using standardized methods developed by the tobacco industry for electronic nicotine delivery systems (ENDS). It will also examine the ICP-MS measurement technique and the many potential sources of interferences observed when determining the most common metals found in vaping devices. Finally, the white paper will pose questions and make suggestions as to how state regulators could use the data to better scrutinize the cannabis vaping industry.