An assessment of heavy metal contaminants related to cannabis-based products in the South African market

Abstract South African cannabis based products that were submitted to a private laboratory for the determination of heavy metal residues, were analysed. Two USP 232/ICH Q3D (United States Pharmacopoeia (USP), 2016; Elder and Teasdale, 2014) [2] specifications were considered for both oral as well as inhalation limits. The presence of each heavy metal residue was also determined in order to establish which residues are most prevalent in samples. To date, no data of this kind exist in South Africa specifically relating to cannabis based medicinal, recreational, or complementary products. A total of 310 samples were analysed in duplicate and are reported in an anonymized format. The submitted samples were divided into different category classifications and grouped according to relevance for oral or inhalation specification. The results showed an alarming 15% sample failure rate compared to the oral specification limit and a 44% failure rate compared to the inhalation specification limit. It is of the utmost importance for manufacturers to have the appropriate quality control regimes in place, especially for heavy metal residues, in South Africa. Furthermore, it is imperative to ensure regulation is enforced and the South African public is educated about the risks associated with using these products.