Certificate of analysis

A document showing the potency and purity of a cannabis product. Provided by a licensed analytical testing lab, the certificate of analysis (COA) lists cannabinoid levels and the testing of pesticides, mold, microbials, and other contaminants, ensuring a product has been tested according to state law and is safe for consumption.

“Never buy a product without seeing its certificate of analysis.”

What is a certificate of analysis?

A certificate of analysis (COA) is what most people refer to as “test results” in reference to cannabis products. It is a document created by a licensed lab that shows the analytical test results on a batch of cannabis products, confirming their potency and purity and ensuring they are safe for consumption. Every state has different testing requirements.

There are two main types of testing done to determine potency and purity: gas chromatography (GC) and high performance liquid chromatography (HPLC). All labs should be able to test for potency, or to determine the cannabinoid content of a sample; for cannabis flower, this is given as a percentage of the dry weight. Purity testing for contaminants can include testing for heavy metals, pesticides, bacteria, microbials, mold, mycotoxins, residual solvents, moisture content or water activity, and the presence of foreign materials. 

Many cannabis companies post COAs of their products on their website for all to see. If a product does not have a COA available, it is advisable for consumers to not buy that product, as it is effectively untested. Usually the full COA will not be on a product’s label, but the potency testing will. To view the full COA, customers should be able to find a QR code on the label, which should take them to the company’s website with the full COA.

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