How to find a trusted cannabis testing lab near you
There is no national registry of cannabis labs. Labs are licensed by states, and accreditation comes from private bodies. Use three sources: your state cannabis regulator's licensee list, the A2LA or PJLA accreditation directory, and the lab license number printed on the certificate of analysis (COA). A lab that appears on all three is verifiable. A lab on none of them is not.
What Does Lab-Tested Cannabis Cost? Testing Fees and Retail Effects
Delivery, curbside pickup, and convenience channels do not change this. Product sold in a state must pass that state's test panel, and the lab that ran the test must hold a license in that state.
What a trusted lab holds
- A state cannabis testing license for the state where the product is sold. Labs cannot test for another state's market.
- ISO/IEC 17025 accreditation from a body such as A2LA or PJLA. Scope matters. The certificate names the methods covered: potency, pesticides, heavy metals, microbials, residual solvents, mycotoxins.
- A published method list with instruments. Common pairings: LC-MS/MS for pesticides and mycotoxins, ICP-MS for heavy metals, GC-MS or GC-FID for residual solvents and terpenes, qPCR or plate counts for microbials.
- A sample ID system that ties the COA to one batch.
What the COA must show
- Lab name, state license number, and accreditation number.
- Sample ID, batch or lot number, date collected, date reported.
- The method used for each test and the limit of quantification (LOQ).
- Numbers compared against state action limits, not a bare pass or fail.
- Panels tested and panels not tested. A blank field is not a pass.
What labs test for
State panels differ. Most cover cannabinoids (THC, CBD, minor cannabinoids), pesticides, heavy metals (lead, cadmium, arsenic, mercury), residual solvents, microbials (Aspergillus, Salmonella, E. coli, total yeast and mold), mycotoxins, water activity, and moisture content. Some states add terpenes, foreign matter, and filth. Hemp testing runs under USDA and FDA rules and is less uniform than state marijuana programs.
How to check a lab in 10 minutes
- Search your state regulator's licensed lab list. Confirm the license is active.
- Search the A2LA or PJLA directory for the lab name. Open the scope PDF.
- Match the scope to the panel on your COA. A scope that lists potency and microbials does not cover pesticides.
- Match the COA sample ID and batch number to the package label.
- Call the lab. Ask which methods run in-house and which are sent to another lab. Subcontracting is allowed in some states and barred in others.
Red flags
- COA with no lab license number, no sample ID, or no batch number.
- Results with no LOQ, or a pass mark with no measured values.
- One COA template reused across products with no batch detail.
- Lab address in a different state than the retailer.
- Report date after the package sell date, or a report date older than the state limit.
State rules and accreditation bodies
Colorado requires licensed marijuana testing labs to hold ISO/IEC 17025 accreditation. California licenses testing labs through the Department of Cannabis Control and requires accreditation. Washington, Oregon, Nevada, and Massachusetts publish their own licensed lab lists. Idaho bans THC sales, so no licensed cannabis labs operate there. The FDA does not accredit cannabis labs.