On October 23, 2020 the WSP Toxicology Laboratory received written notification from Millipore Sigma/Cerilliant informing customers of an issue impacting one of its products. An additional follow-up notification was received October 26, 2020. Both notification letters are attached.

Cerilliant_THC Qual Notice_20201015.pdf

The product in question is the Delta-9-THC (THC) Certified Reference Material, lot #FE08221804. Millipore Sigma/Cerilliant confirms that the certified concentration of this THC Certified Reference Material remains the same; however, the measurement uncertainty value for this lot has increased. 

The WSP Toxicology Laboratory has used this product multiple times from July 31, 2019 to date for the preparation of THC calibrators and controls, which are in turn used for the identification and quantitation of THC in forensic casework. The WSP Toxicology Laboratory has concluded that THC measurement uncertainty ranges for results reported from testing performed from July 31, 2019 to date, will be impacted by this change. 

The WSP Toxicology Laboratory needs additional time to calculate and validate the revised measurement uncertainty value for THC results reported since July 31, 2019. In the meantime, the WSP Toxicology Laboratory has purchased new THC Certified Reference Materials with different lot numbers and has prepared replacement THC calibrator and control materials.

The revisions will not afffect any THC result.  The revisions relate only to the measurement uncertainty, which will expand to address the above revision.  

If you have any questions regarding a THC result, contact the analyst in your case.

Although this revision is expected to have little or no effect on case dispositions, prudent prosecutors will notify defense attorneys in affected cases.   Expect a listing of cases from the toxicology laboratory to be posted and distributed.