Heavy metal testing for cannabis products has gained significant momentum in the past 12 months, not only due to a link identified between the recent outbreak of vaping related illnesses and heavy metals exposure. However, instead of just focusing on testing the raw cannabis material, there has been significant evidence that leachability from packaging may also be to blame.
Analyzing cannabis for contaminants is important to ensure the products being sold are safe for consumption. Heavy metals analysis is crucial for cannabis due to the dangers associated with the consumption or inhalation of these compounds. Heavy metals poisoning can occur if metals such as arsenic, cadmium, lead, and mercury accumulate in the body. Further, cannabis is an accumulator plant, which means that it can survive in environmental conditions that many other plants would not thrive in. Many plants and crops cannot survive if there are excessive amounts of any one metal present. The metal will deprive the plant of nutrients and it will eventually die. However, cannabis simply absorbs those metals and allows them to become concentrated in the plant.
To test for heavy metals, there is a preferred testing method using EPA Method 6020B and EPA 3051A. EPA 6020B uses an inductively coupled plasma with mass spectrometry to detect metals in concentrations that are sub-ug/L in fully digested samples. EPA 3051A uses microwave-assisted acid digestion to prep samples which are not already in solution such as flower, distillate, wax, shatter, tinctures, and even edibles.
Quality control is critical in heavy metal testing for cannabis products. In order to trust data reported by a testing laboratory, they should present quality control data that shows the results obtained are reproducible, reliable, and defensible. Full quality control is analyzed with each analytical batch to ensure that the results are accurate.
As more states and countries pass laws regarding the recreational use of cannabis, analytical testing needs to be performed on all products prior to sale. For heavy metals specifically, testing is going to be of greater importance due to the use of vape cartridges. Heavy metals leaching from the packaging into the product has been identified as a potential issue, which makes it imperative that the final product in its packaging is tested for heavy metals at a minimum.
In conclusion, heavy metal testing for cannabis products is crucial to ensure the safety of consumers. Laboratories need to use standardized methods, ensure quality control is in place, and keep up with the ever-increasing demand for analytical testing as laws change regarding recreational cannabis.