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Required Testing for Hemp Crops and Hemp Products

March 19, 2021
hemp testing scale

March 19, 2021 | Montpelier, VT - The Vermont Agency of Agriculture, Food and Markets’ Hemp Program reminds hemp growers and processors of their obligation to comply with the Vermont Hemp Rules including testing requirements that reduce risk and help protect the consuming public.  All hemp crops, processed hemp and hemp-infused products must be tested and meet potency and contaminant action limits.  Some action limits for processed products can be met at the hemp crop harvest lot or hemp concentrate process lot testing phase. For instance, a hemp product, such as a tincture, would be compliant if the concentrate used in manufacturing the tincture complies with contaminant thresholds for microbiological, residual solvents, pesticides, and heavy metal contaminants.  Therefore, having test results at this phase of processing can reduce the amount of testing at the final product stage.  Trim flower must be tested at the product stage for both moisture/water activity and microbiological contaminants.

Testing Areas

  • Potency testing determines the level of cannabinoids present in a sample.  The Hemp Program has action limits for delta 9-THC and Total THC, for crops, trim flower, products and infused products.
  • Moisture or Water Activity analysis determines the amount of water in a sample or the relative chemical potential energy of water.  Moisture analysis is used to calculate dry weight potency and contaminant concentrations for crops and trim flower.  In addition, processed trim flower also has action limits for moisture or water activity.  The drier the hemp the less likely the material can support microbiological growth.  Using best practices in hemp drying and storage can also help minimize microbiological growth. 
  • Microbiological analysis includes three different tests: total aerobic bacteria, total combined yeast and mold, and mycotoxins.  Testing at trim flower and concentrate stage will satisfy this requirement for testing.  Mycotoxins are toxic, and therefore have a low action limit of 20 ppb (parts per billion).
  • Heavy Metals analysis is required for all concentrates and for crops grown on former orchard or non-agricultural use lands. A compliant soil test can be done in place of crop testing. Heavy metals can be present in the soil, air and water, and can also be taken up by the cannabis plant.
  • Pesticide testing includes 15 compounds.  Sources of pesticides in hemp include inappropriate application, drift from nearby agricultural fields, or contact with contaminated agricultural or processing equipment.  Hemp crops must be tested if they are not certified organic.  “Hemp concentrates” always require testing, as extraction can concentrate pesticides to harmful levels.
  • Residual solvents are tested when solvent-based extraction techniques are used in either primary botanical extraction or secondary processing.  This includes ethanol winterization of CO2 extractions.    For hemp products and infused products, a food grade solvent is allowed if it is in the ingredient list of the final product.

Cannabinoid Content Label Claims

Label claims for cannabinoid content should be tested at the level of the marketed product. A processor should be able to produce a product with the same cannabinoid concentration using the same standard operating procedure and standardized ingredient list. A certificate of analysis demonstrating cannabinoid content in the final product may be used as proof of a label guarantee, and it would not be necessary to test every process lot of a product line for cannabinoid potency. Maintaining records of all the manufacturing steps, ingredients, and test records by product line is expected in order to be in compliance.  The Hemp Program recommends periodically retesting product lines and if necessary, updating procedures to ensure consistency.

Please refer to the Vermont Hemp Rules to learn when analytical testing for potency and contaminants are necessary, and requirements for using label guarantees, and labeling requirements, as well as, record-keeping requirements for all test results from seed to shelf, .

These testing requirements and hemp potency and contaminant action limits can also be found here, Specifically, table 2 lists testing requirements, and tables 3 through 8 list threshold levels (action limits) that must not be exceeded for the hemp crop or product to be compliant. 

Questions about the requirements for hemp testing can be directed to Cannabis Quality Control Program Compliance Specialist, Bob Shipman: , or