Using Method Detection Limits to Set Mandatory Reporting Limits for Banned Pesticides: How a Public-Private Partnership Improved Cannabis Regulation in Colorado

Author(s): Joseph Konschnik1, Heather Krug2, Shawn Kassner3
1. Restek Corporation, 2. Colorado Department of Public Health & Environment (CDPHE), 3. Neptune and Company, Inc.

Published By: Cannabis Science and Technology

Issue: 1

Year of Publication: 2018


Abstract: The discovery of nonregistered pesticides contamination in cannabis plant material in Colorado prompted the need to set mandatory reporting limits (MRLs) for these pesticides in the state to ensure public safety. Since then, the Colorado Department of Public Health and Environment (CDPHE) undertook the responsibility for setting such MRLs. Colorado’s novel approach to determine MRLs for each pesticide involved forming a working group with its in-state laboratories and expert volunteers to agree on analytical procedures to determine method detection limits (MDLs) using an industry-standard approach. The authors describe how this approach formed a collaborative public-private partnership where state government agencies worked side by side with laboratories and growers toward a common goal. The multilaboratory study was completed yielding MDLs for 13 pesticides in cannabis flowers using a QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction with analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The authors share the procedures used for the study, an overview of the data generated by the participating laboratories, and the new Colorado MRLs, which became effective on January 1, 2018.