September 28, 2020

ROCKVILLE, MARYLAND, USA, September 28, 2020 —AOAC INTERNATIONAL has launched a new project to develop technical requirements, evaluate, and certify the performance of test kits that enumerate total yeast and mold organisms in cannabis flower.

The project will employ the Emergency Response Validation option of the AOAC Research Institute’s Performance Tested Methods (PTM) and AOAC INTERNATIONAL’s Official Methods of AnalysisSM(OMA) programs with oversite from the Cannabis Analytical Science Program (CASP) advisory council.

This joint project will allow for the rapid development of emergency Standard Method Performance RequirementsSM (SMPRs) through CASP to provide acceptance criteria for method validation while conducting an evaluation and review of multiple test kit models in parallel through the PTM and OMA Programs to accelerate the availability and variety of certified test kits.

Yeasts and molds represent the two different forms of fungi that can grow in a wide range of environmental conditions, resulting in contamination of products and significant economic loss. In the absence of a federal framework of regulations for cannabis, states have individually developed microbial testing requirements and set action limits for approving or rejecting batches. Most states have set action levels at one of two concentrations for total yeast and mold analysis: < 103 or 104 CFU/g. It is estimated that between 10 and 20 percent of cannabis batches fail these microbial contaminant requirements1. Recent surveys of cannabis products determined the presence of over 4,000 different fungal taxonomic classifications in cannabis flower, including several pathogenic fungal agents. 

To ensure safer products are reaching consumers, regulators with states have requested that testing facilities use AOAC validated methods. However, no AOAC certified methods for yeast and mold enumeration in cannabis products are available. The objective of this project will be to create an emergency SMPR while concurrently performing a matrix extension to cannabis flower for PTM or OMA certified yeast and mold methods or grant an Emergency Response PTM status for new methods.

The project is projected to be underway on or about October 15, 2020. Regulators, method developers or cannabis/hemp laboratories interested in becoming a part of CASP or submitting a method as part of the validation study are encouraged to get involved. 

For more information about submitting a method or becoming involved in CASP, contact Scott Coates at scoates@aoac.org, 301-924-7077 ext. 137 or Deborah McKenzie at dmckenzie@aoac.org , 301-924-7077 ext. 157.


  1. MED 2019 Annual Update, Colorado Department of Revenue Enforcement Division, 2019