Ensuring Clean Cannabis: A Look at the Role of Third-Party Testing Labs

Third-party cannabis testing laboratories play a crucial role in ensuring product safety, compliance, and consumer trust across the United States. Because cannabis remains federally illegal, there is no unified national framework for testing. Instead, each state has adopted its own regulations for lab licensing, testing panels, and quality standards. Many states require cannabis labs to be accredited under ISO/IEC 17025, the international standard for laboratory competence, with accreditation bodies such as A2LA providing cannabis-specific programs. Hemp testing falls under a slightly different category—under the 2018 Farm Bill, laboratories testing THC in hemp must be registered with the DEA by the end of 2025. Some states, like California and Maryland, have established reference labs to audit or validate the work of third-party facilities in order to prevent inconsistencies and fraud.

This patchwork system has created challenges. One of the most significant is “lab shopping,” where cultivators send samples to labs known to produce more favorable results—such as higher THC readings or fewer contaminants. A Connecticut lab was recently sued over allegedly inflated THC results, highlighting how problematic this practice can be. States also differ in what they require labs to test, ranging from pesticides and heavy metals to microbes and residual solvents. On top of that, cannabis degrades over time, so sample handling, storage, and turnaround speed are critical. Accreditation costs and method validation further complicate the landscape, as labs must invest heavily in technology like GC-MS, ICP-MS, and qPCR to remain compliant. When testing errors occur, the results can be severe—Michigan issued a major recall in 2021 after questions arose about one laboratory’s practices.

Despite these obstacles, several well-established third-party laboratories have built strong reputations across the country. Kaycha Labs operates multiple locations nationwide, including Arizona, Colorado, Florida, and Massachusetts, and emphasizes automation and consistency. SC Labs provides compliance, R&D, and quality control testing across cannabis and hemp, with services ranging from potency to pesticide screening. Encore Labs, accredited under ISO/IEC 17025:2017, offers testing for cannabinoids, microbes, metals, solvents, and terpenes, serving California and Arizona clients. ACS Laboratory, based in Florida, is one of the largest hemp and cannabis testing facilities in the U.S., offering panels that include cannabinoids, kratom, and mushrooms. Confidence Analytics focuses on ISO-accredited cannabis testing and prides itself on rigorous traceability. Steep Hill, founded in 2007, was one of the first commercial cannabis labs and remains active with a blend of analytics, research, and consulting. Modern Canna, operating in Florida, is another respected option for both medical cannabis and hemp testing.

For cannabis brands, cultivators, and manufacturers, choosing the right testing partner is critical. Clients should confirm ISO/IEC 17025 accreditation and make sure the lab’s accreditation scope covers the specific analyses they require. They should also review method validation data such as detection limits, precision, and uncertainty estimates, since these details can make or break the reliability of a result. Turnaround time is another consideration, but fast results should never come at the expense of scientific rigor. Solid chain-of-custody practices and sample handling protocols protect against degradation or contamination. Some companies even cross-check batches with multiple labs to validate consistency, especially in competitive or high-risk markets. Above all, it is important to confirm which testing panels are required for the state where the product will be sold, as compliance rules differ widely.

Looking ahead, the cannabis testing sector will likely remain fragmented until federal legalization creates the possibility of national standards. In the meantime, third-party labs are under increasing pressure to adopt standardized methods, participate in inter-lab proficiency programs, and submit to reference lab audits. These steps may help close the gaps between states and build stronger consumer trust in a market where consistency and safety are paramount.