Regulations of pesticides in cannabis

Abstract

Accurate determination of pesticide residues in medicinal cannabis is increasingly recognised as a necessary contributor to the safety of medicinal cannabis products. The aims of the study were (i) to identify and compare analytical methods for the determination of pesticides in herbal products and cannabis, and (ii) to identify and compare regulations related to allowed pesticides and their limits in medicinal cannabis in different countries. Systematic literature review was carried out to identify different analytical techniques for the detection of pesticides in herbal products and cannabis. Regulations for the use of pesticides in cannabis were identified using official government websites of different countries. Testing requirements, number of pesticides tested for and allowed limits were compared. Fifteen articles describing the analysis of pesticides in cannabis were identified. High-performance liquid chromatography is the most common (n= 9) analytical technique for the detection of pesticides in cannabis. QuEChERS was the most commonly (n = 3) used sample preparation technique, and Shimadzu was the most commonly used HPLC unit (n = 4). Gas chromatography (n = 4) and ultra-high-performance liquid chromatography (n = 2) were the other two analytical techniques identified. Regulations for the use of pesticides in cannabis are found in 14 countries and a further two countries are currently drafting regulations for the use of pesticides in cannabis. In Thailand, analysis is done in accordance with the Thai Pharmacopoeia which sets residue limits for 70 pesticides. Malta, The Netherlands, Denmark, Germany, Australia and New Zealand follow the European Pharmacopoeia guidelines, which require testing of 69 pesticides and their allowed limits. In Morocco and Zimbabwe, in the cultivation of cannabis, authorised and licensed pesticides should only be used if use is justified. In Israel, a registered pesticide may only be applied to cannabis if compliance with the instructions for use specified on the label is followed. In the United States of America, medicinal cannabis is legalised in 38 states. No pesticides are federally registered for use on cannabis; however, most states have their own guidelines and lists of approved pesticides. In Canada, 96 pesticides are to be tested for, each including different limits of quantification, depending on the dosage form. Jamaica and Costa Rica are currently in the process of drafting regulations for the use of pesticides in cannabis. The study helped identify differences and similarities between analytical techniques and guidelines for the use of pesticides in cannabis. Harmonised regulations help improve the quality and safety of medicinal cannabis products.