On August 11, 2021, Legend Technical Services, the lab the MDA contracts with to perform MDA’s regulatory lab work for the hemp program, notified MDA that a technical issue occurred from March through October 2020. Legend had obtained and used a certified calibration standard manufactured by Restek to conduct testing for THCA-A, a component of Total THC. As part of a routine proficiency test for THCA-A in October 2020, Legend found that it did not meet acceptable limits. Legend conducted an investigation as a result of the proficiency testing results and determined that the standard used for THCA-A had been recalled by the manufacturer, Restek. Legend had not been notified of the recall by Thermo Fisher Scientific, the supplier of the Restek standard.

Legend Technical Services notified the MDA that Total THC may have been overestimated in 2020 testing and supplied a list of samples that may have been impacted by the use of the recalled standard. Test results from 16 growers collected in 2020 may have overestimated Total THC by as much as 0.05 percent. Those 16 growers have been notified about the testing issue.

The MDA has compiled information to frequently asked questions about the situation. Legend Technical Services has provided answers to several questions that are beyond the MDA’s scope of work. Those answers are noted below. The FAQ will update as more information is received.

If you have any questions, please submit in writing to hemp.mda@state.mn.us.

Legend Technical Services informed us that 29 hemp lots were impacted because the total THC fell between 0.40 and 0.45%. The impacted lots came from 16 growers. This event occurred during the pilot program when the MDA identified any sample with Total THC less than or equal to 0.399% as in compliance and any result greater than or equal to 0.40% as out of compliance, a failure.

The calibration standard was purchased from Thermo Fisher Scientific but manufactured by Restek. Restek is an ISO 17034:2016 accredited analytical standard manufacturer. (Answer provided by Legend Technical Services)

The MDA has identified four changes to their protocols for testing.

  • The MDA will require their regulatory lab to store samples at -20°C so that a sample can be retested. Any sample with a failing result should be stored until the case is closed.
  • The MDA will require that proficiency test results are provided within 10 business days from receipt. Proficiency testing is performed by accredited laboratories to compare their analytical procedures to a known sample and determine any variability that may exist. This allows the accredited laboratory to determine if acceptable limits of variance are being met to ensure the most accurate sample reading. The MDA will review results for every proficiency test and take appropriate action if proficiency test results do not meet acceptance criteria. This action may include suspending regulatory decisions until the lab can demonstrate proficiency or utilizing another accredited lab for regulatory testing.
  • The MDA will develop a process to validate the accuracy of lab results.
  • Future contracts for hemp regulatory testing will require the MDA be notified within 24 to 48 hours for any event that impacts testing.

No. The calibration standard provided by Restek was discovered to be lower in concentration than expected. It is not clear what the exact value was and, therefore, THCA-A estimates cannot be recalculated. We do not know with any certainty what the Total THC would have been. The sample may have passed, or it may have failed.

The investigation related to this analytical standard recall involved the review of hundreds of sample work orders from March 2020 – October 2020.  Due to the sheer amount of sample data that required review, the investigation took a significant amount of time, which resulted in the delay in notification. (Answer provided by Legend Technical Services)

The proficiency testing results for THCA-A were above the proficiency testing acceptable limits by approximately 10%. (Answer provided by Legend Technical Services)

The MDA has a contract with Legend Technical Services. At the time, this contract established Legend as a sole provider of cannabis testing because they provided services to Minnesota’s Office of Medical Cannabis. Legend’s experience with cannabis, their accreditation for cannabis testing, and their ability to provide the needed services for the regulatory program were criteria used in their selection. As an ISO17025 accredited lab, Legend has a quality assurance program that meets international standards and includes the following:

  • Proficiency testing
  • Traceability of all reagents, including standards, is required so that labs can determine which test results are impact when a reagent is out of specification
  • Customer notification is required if there may be a problem with test results
  • Legend met all of these requirements in this situation

Restek is an ISO 17034:2016 accredited, analytical standard manufacturer that Legend purchases cannabis related standards from.  (Answer provided by Legend Technical Services) Read the recall notice (PDF).

Themo Fisher Scientific is a distributor of analytical standards, consumables, and supplies. Legend purchased the recalled Restek analytical standards through Thermo Fisher Scientific. (Answer provided by Legend Technical Services)

No, because there is no ability to know whether your crops would have passed or still would have failed.