ISO/IEC 17025, "General requirements for the competence of testing and calibration laboratories", sets out how a lab must manage its methods, staff, equipment, traceability, measurement uncertainty, quality control and reporting. An independent accreditation body assesses the lab and grants accreditation for a defined scope: specific tests on specific sample types.
In practice
Check the scope, not just the logo. A lab can be accredited for potency in flower by HPLC but not for pesticides or for concentrates. A COA from an accredited lab should name the accreditation body and certificate number; most bodies publish searchable scopes. Accreditation shows the lab has a working quality system and has been assessed; it doesn't guarantee every number, and documented lab-to-lab bias has occurred among accredited labs. Many regulated markets require it; check local rules.
Don't confuse with
- ISO 9001: a general quality-management standard, not specific to testing competence.
- State licence: permission to operate as a cannabis lab, separate from accreditation.
- Proficiency testing: one ongoing requirement within 17025.
Track-and-trace is the ability to follow a regulated product through the supply chain and back to its source, the basis of cannabis tracking and recalls.Measurement uncertainty is the quantified range around a lab result within which the true value is expected to lie, typically stated as ± a value at about 95% confidence.HPLC (high-performance liquid chromatography) separates compounds dissolved in a liquid under pressure; it is the standard cannabis potency method because it measures acid cannabinoids without heating them.A COA (certificate of analysis) is a lab's signed report of what it measured in a specific sample, such as cannabinoids, terpenes, moisture and contaminants, with methods and limits.Proficiency testing sends identical blind samples to many labs and compares their results with an assigned value, checking each lab's accuracy against its peers.Lab shopping is the practice of choosing testing labs because they report higher potency or more passing results, rather than because they are most accurate.Potency testing is laboratory measurement of a sample's cannabinoid content, normally by HPLC, reported as % w/w or mg/g for each cannabinoid plus calculated totals.
