Cannabis Testing Requirements

California is one of a few states that allows the legal sale of cannabinoids, but it isn’t as simple as growing the plant and then selling it. The state of California has fairly stringent laws about the processing and testing of cannabis products, requiring a number of different licenses at every step. For laboratories processing cannabis products, there are several requirements for testing that must be passed in order for it to be ready for sale.  

There are a number of tests that need to be performed on the product before it’s allowed to be sold. Each of these testing steps were phased into the standard, starting with the first phase which contained testing for cannabinoids, moisture content, category 2 residual solvents and processing chemicals, category 1 residual pesticide testing, microbial impurities testing (for E. coli and Salmonella spp., as well as A. fumigatus, A. flavus, A. niger, and A. terreus), and homogeneity testing of edible cannabis products. The second phase involved testing for category 1 residual solvents and processing chemicals and category 2 residual pesticides and foreign materials testing, and the final of the three phases involves testing for terpenoids, mycotoxins, heavy metals and water activity testing for solid or semi-solid edibles. As for the dates they will be or were initiated, the first phase was brought into effect in January, the second in July, and the third has yet to be enacted but will go into effect in December.

Now, this isn’t to say that every form of cannabis has to be tested for these. Inhalable cannabis intended to be smoked as is does not require solvents testing, as they are not processed in the same way that cannabis products are, nor do they require edible cannabis product testing because it is not intended to be ingested in that manner. Inhaled cannabis products like vape liquid don’t require moisture testing like solid cannabis, nor does it require edible cannabis product testing or water testing on solid cannabis, because this product comes in a liquid form already. Finally, edible cannabinoids and other products don’t have to test for Aspergillus growth because it is generally believed that ingestion of this bacteria isn’t as dangerous as inhalation. Cannabinoids for alternative means of ingestion also don’t have to test for moisture content as solid cannabis intended for smoking does. Despite this, labs that are developing protocol to test for a particular kind of preparation of cannabis would be wise to develop standard operating procedures for all variety of testing that the California Bureau of Cannabis Control (BCC) is expecting.  

But what do these tests mean and how do cannabis testing laboratories perform all of these tests on their product? One of the first tests is one for uncovering cannabinoid content, which requires the lab to test for amounts of tetrahydrocannabol (THC), tetrahydrocannabolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabigerol (CBG) and cannabinol (CBN). Moisture content is, quite simply, the amount of moisture in solid cannabis for smoking and is a test where the sample is allowed to pass if and only if the moisture content isn’t higher than 13%.

Category 2 pesticides are pesticides that can cause toxicity anywhere between 0.2 mg/mL and 2 mg/mL, category 1 pesticides cause toxic death around half of the population from a near zero dose to 0.2 mg/mL. (1) Because it is past the phase to integrate phase one and two, pesticides in both of these categories must be tested for (and hopefully, removed from the cannabinoid product). Likewise, solvents are chemicals used during the processing phase of cannabis extraction, with category 1 being the more toxic between categories 1 and 2. However, the concentrations needed to harm can be even smaller, with some of the solvents needing only 2 parts per million to cause serious toxicity in category 1 and 50 parts per million in category 2. (2) This of course varies from solvent to solvent, based on the toxicity of the solvent (whereas pesticides will largely have the same toxicity no matter the weight.) The more general rule is that category 1 is more deadly than category 2.

Microbial impurities testing is obvious; bacteria is not only something that is everywhere in our everyday lives, but can cause illness and as such should be carefully monitored when preparing any sort of food or drug for sale. For current safety standards, E. coli and Salmonella, must be at levels of not detectable per gram of cannabis and inhaled cannabis must test for A. fumigatus, A. flavus, A. niger, and A. terreus  as well. Homogeneity of edible cannabis helps ensure the consistency of the product for sale with edibles, guaranteeing that the customer gets what they paid for rather than anything they didn’t. Foreign materials testing is done visually by checking for dirt, mold, organic material (like insect wings or mammal hair), or if it’s covered by a foreign material.

Terpenoid testing looks for the both the amount of terpenoids and whether or not the profile is the same as the standard terpenoid profile for that particular plant. If the amount recorded is within 10% of the labelled amount, then this test is passed, if greater or less than the amount on the label, the test fails. Mycotoxins are a form of toxin produced by fungi, and cannot exceed 20 µg/kg of substance for aflaotoxin B1, B2, G1 and G2 or ochratoxin A. Heavy metals testing involves testing for toxic heavy metals like cadmium, mercury, lead and arsenic. Finally, water activity is tested for solid or semi-solid cannabis. Water activity is whether or not the water ‘bound’ or ‘moves’ within a substance and is used for shelf stability and prevention of mold growth, and helps with the stability of such cannabis in general. (3)

At this point, any existing cannabis testing labs should already at least have ideas about how to approach these sorts of tests, and how any that are hoping to break into the business should go about fulfilling these requirements. While each company develops their own standard operating procedures of how to test for these standards, but this is not the only thing that labs are expected to generate, a report based on whether these products pass or fail these evaluations. All of these limits can be placed in QBench, for example, which can also aid with the next major part of this process: reporting.

Once all of these stringent analyses are complete, the lab must generate a standardized report. In our next article, we’ll discuss what needs to be in this sort of report, we hope to see you then.

(1)- Smith, D. W. Pesticide Toxicity”. Texas Cooperative Extension, Texas A&M University System. Retrieved from ALS Environmental Testing Lab. Retrieved from

(3)- Decagon Services “Fundamentals of Water Activity”. Retrieved from