California Cannabis Testing Labs

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Does California License Independent Cannabis Testing Labs?

California requires cannabis testing laboratories to be independent and third-party-owned. Consequently, to forestall any potential conflict of interest between laboratories and their clients, cannabis testing laboratory licensees must not hold other cannabis business licenses. To test cannabis legally in California, a laboratory must be licensed by the California Department of Cannabis Control. Testing laboratory licensees in the state are authorized to test both medical and recreational marijuana products.

Requirements for Marijuana Testing Labs in California

Not all laboratories can test cannabis products in California. To be certified by the state to test cannabis products, a laboratory must maintain an ISO/IEC 17025 accreditation. An ISO accreditation is a measure of the quality used by research centers and universities worldwide. An ISO/IEC 17025 requires testing laboratories to show the reliability of test results and technical competency.

In addition, testing laboratories are required to use standard operating procedures, participate in a proficiency testing program, and develop a laboratory quality assurance program.

California Required Tests for Cannabis Products

Every batch of cannabis sold legally in California must be tested for over 100 contaminants. The contaminants identified by the Department of Cannabis Control are grouped into the following categories:

  • Cannabinoids and terpenes
  • Heavy metals
  • Foreign material
  • Microbial impurities
  • Residual pesticides
  • Residual solvents and processing chemicals
  • Mycotoxins
  • Moisture content and water activity

How Do California Marijuana Testing Labs Submit and Report Test Results?

California-licensed cannabis testing laboratories report cannabis test results for marijuana products on a CoA (Certificate of Analysis). The CoA states whether a product batch passes or fails testing for each substance. Testing laboratories are only allowed to issue CoAs after tests for all products in a batch have been completed. They are not allowed to change the results, without permission, after the CoAs have been issued by the California Department of Cannabis Control.

Per California DCC regulations, within one day of completing a batch's testing, the certified testing laboratory must upload the CoA to the DCC's track and trace system and send a copy of the CoA to the DCC via email at

How Much Does It Cost to Test Cannabis in California?

Cannabis testing costs in California vary depending on several factors, such as the size of the laboratory and the economies of scale in the use of laboratory equipment, space, and labor. According to research published by the University of California, Agriculture, and Natural Resources, large laboratories charge approximately $324 per sample, medium-sized laboratories charge about $562 per sample, while small testing laboratories charge about $750 per sample.

The published research categorized laboratory sizes by the number of samples analyzed annually. Laboratories analyzing about 2,200 samples yearly were classified as small laboratories. Those handling about 6,190 samples annually were categorized as medium-sized laboratories, while laboratories testing up to 23,160 samples were deemed large.

Another study undertaken by researchers at the University of California finds that laboratory tests cost about 10% of the average wholesale price of legal cannabis.

What Happens to Cannabis Products That Fail Lab Tests in California?

The California Department of Cannabis Control requires batches of cannabis goods that fail testing to be destroyed by the distributor or remediated by a manufacturer. Only licensed cannabis manufacturers are permitted to remediate a product, and the DCC must approve any remediation plan in advance. Cannabis remediation refers to removing various contaminants and undesirable compounds from cannabis products.

After remediation, cannabis goods must be retested to ensure the contaminants have been removed. If the goods pass the retesting process, they may be sold legally. Cannabis business licensees looking to remediate cannabis goods in California may submit their remediation plans to the DCC via email at

List of Cannabis Testing Labs in California

Although the state does not provide a list of licensed cannabis testing laboratories in California, there are over 30 testing labs with active DCC-issued licenses. The DCC provides a search tool on its website for users to find registered cannabis businesses, including testing laboratories.

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