Does Laboratory Accreditation Assure Accurate Cannabis Testing?

Importance of Laboratory Accreditation for Cannabis Testing Laboratories

One of the most widely recognized standards internationally for cannabis testing laboratories is ISO/IEC 17025. Many states in the US have made ISO/IEC 17025 accreditation mandatory for cannabis testing laboratories. All 3rd party cannabis testing laboratories must adhere to the ISO/IEC 17025:2017 standard. Laboratory accreditation is essential to ensure that a laboratory’s operations are in accordance with international standards. For example, during ISO 17025 audits, the auditors determine if a laboratory has proper standard operating procedures (SOPs) for all laboratory procedures, has quality control practices in place, and validates all test methods before use. ISO/IEC 17025 accreditors also ascertain if laboratory equipment is properly validated and calibrated and the laboratory has well-trained technicians.

Accreditation assures that there is a written record of all procedures taking place in a laboratory. An accredited laboratory should have proper, predefined SOPs for sampling, sample preparation, instrument calibration, staff training, record maintenance, and management best practices. Accreditation assures that laboratory professionals are trained to perform analytical tests properly in order to generate accurate test results.

ISO/IEC 17025 Accreditation: Does it Assure Accurate Cannabis Testing?

Accredited laboratories should ideally always get the same results on the same samples. However, many accredited laboratories can have variations in the results of the same samples. There can be several reasons for such differences. Some of them are outlined below:

1. SOPs: Many laboratories confuse quality manuals with SOPs. SOPs are a set of step-by-step instructions to help staff perform daily laboratory operations. On the other hand, a quality manual holds information regarding a laboratory’s quality management system, quality objectives, and policies. Several laboratories use the quality manual as their SOPs, which is not appropriate.Many analysts do not follow pre-defined SOPs correctly in the absence of constant supervision. Hence, laboratories must implement a way to monitor if staff members are following SOPs.
2. Scientific Verification of SOPs: Auditors determine if a laboratory has documented SOPs in the required format and are easily accessible to authorized analysts. However, they do not ascertain if the SOPs are scientifically correct. Unless the SOPs are scientifically verified, inter-laboratory variation in test results will continue to happen.
3. Test Method Transfer (TMT): Cannabis testing laboratories either develop their test methods in-house or use validated test methods provided by equipment vendors. Many times, laboratories use the methods suggested by equipment vendors for testing products without formally verifying those methods. Laboratories must verify the test methods by comparing the results of the tests performed by the vendor’s analysts using the vendor’s equipment, reagents, and standards with the test results performed using their own equipment, analysts, standards, and reagents by running the same test method. This procedure of formal verification of test methods is known as Test Method Transfer (TMT).If variation in test results is observed due to lack of TMT, laboratories sometimes make changes to the test method without any supporting data, and the resulting modified method is considered as the validated method for a particular test. The ISO 17025 standard requires cannabis testing laboratories to use validated methods; however, it does not require laboratories to define and record changes to test methods. This creates a scope for inaccurate results and inter-laboratory variation in test results.
4. Change Management: The ISO/IEC 17025 standard does not provide precise guidelines to laboratories to manage change control. It requires laboratories to track changes or modifications in documents; however, it does not provide specific requirements for making procedural changes or changes to test methods. Furthermore, the standard does not specify the data or evidence required to justify the changes made.Due to the lack of clear instructions to manage changes, cannabis testing laboratories sometimes fail to maintain a record of the changes made to laboratory procedures or test methods. They do not have any data or documents justifying the changes done to a process or test method, nor does there exist any record of the laboratory personnel who make or approve such changes. This raises a concern regarding the authenticity and accuracy of final test results.