Lab Tests Ensure All Licensed Cannabis is Clean Cannabis


If you shop at farmer’s markets, you’ll appreciate that all cannabis sold in licensed retail stores in California is being held to stringent standards that far exceed those for products labeled organic*. This means that effective next week, your weed will be safer than your food, thanks to the regulations put into place by the Adult Use of Marijuana Act.

Starting on July 1st, all cannabis products including flowers, vaporizer cartridges, concentrates, edibles and topicals must undergo a series of “Phase II” tests for cannabinoid potency, as well as possible contamination from pesticides, microbes, and residual solvents used in creating concentrated oils.

While many cannabusinesses voluntarily tested their products in the past, sharing results in the interest of being transparent and responsible, now the state has codified the process by setting up universal standards for the entire industry. Products that fail compliance testing are not legal for licensed retailers to sell and must be destroyed.

Potency Testing

All cannabis products must be tested for the amount of THC and CBD they contain, and this information will be included on all packaging. For consumers, this means you’ll be able to choose flowers ranging from 10% to 30%+ THC, making it easy to find the strength you most enjoy.

Edibles companies have the biggest challenges to overcome when it comes to acing a lab test, due to the unique natures of their products and difficulty in homogenizing THC across entire batches of cookies or brownies. In the past, companies have come under fire for making items that fail to match their label claims for cannabinoid potency, with a three-month investigation undertaken by The Oregonian finding plenty of inconsistencies with product they purchased in 2015.

As of July 1st, all edible cannabis products will be tested for homeogeneity, meaning that the average potency of the servings within the product must fall within 10% of the label claims. For example, a chocolate bar that claims to have 100 milligrams of THC divided among 10 servings must come within 90 - 100 mg as verified by the lab, and if it tests over 100mg, it’s against the law for a retailer to sell it. The smaller the microdose, the tougher this can be to standardize: a single cookie claiming to be 5mg must test between 4.5 - 5.5 mg of THC or be thrown out.

Here's an example of a product label that displays lab-tested information including a complete terpene profile.

Here's an example of a product label that displays lab-tested information including a complete terpene profile.


The state has set strict thresholds for acceptable levels of residue on cannabis, requiring product be screened for 66 different types of pesticides and chemicals, ensuring that everything is safe and completely free of any contamination. Upgrading testing systems for these much more rigorous standards necessitated laboratories to invest in sensitive “mass spec” machines, capable of techniques known as liquid chromatography and gas chromatography, which analyze substances down to parts per million.

*Even if a cannabis product passes the pesticide screening, it cannot be labeled as “organic” since that term is regulated by the USDA, a Federal agency that isn’t allowed to recognize the state-legal status of cannabis.


Labs will conduct pass / fail tests for microscopic life including nasty bugs like e. Coli and salmonella, as well as carcinogenic aflatoxins (mold), so you can be rest assured that you’re not inhaling anything harmful.

Residual Solvents

Concentrated cannabis products like the oils that end up in vaporizer cartridges, or the variety of extracts including shatter, butter, diamonds, sauce, wax, crumbles and sugars will all be tested for residual solvents, making sure these substances have been purged completely or at least below an acceptable threshold.


Currently, cannabis products are not required to test for terpene content. However, if claims are made about terpene content on labeling, then those claims must be backed up by lab tests.

Phase Three Testing

Starting in 2019, the state will require compliance with the third and final phase of mandatory lab testing, adding standards for mycotoxins (fungi), heavy metals and excessive moisture known as “water activity.” There will also be terpene testing required in 2019.

State-Certified Labs

In addition to all of the standards that cannabis products must meet, the state is now regulating the laboratories that perform these services as well. Previously, you’d hear rumors about less-than-reputable labs altering test results in return for kickbacks, falsely inflating THC values and other unscrupulous behavior. Even when well-intentioned, many labs had staff that wasn’t properly trained in operating equipment, leading to inconsistent results and less-than-stellar service quality.

Now, all labs must be licensed by the state, as well as accredited by the International Organization for Standardization. Strict regulations govern how the labs can do business, mandating detailed plans for chain of custody for samples, employee training, storage and more.