What is a fatal flaw in a drug test and what does it entail?

By John Hawes | Last updated: January 17, 2019

A fatal flaw is a critical error that was made during the collection process that cannot be corrected. Primarily, fatal flaws are related to lab-based testing, as laboratories have certain requirements related to the chain of custody form that must be completed, as well as certain requirements regarding how the sample is packaged. There are 7 fatal flaws that would cause a sample to be rejected for testing:

1. No Chain of Custody Form (CCF) is provided with the sample

2. There is no specimen submitted with the CCF.

3. The collector has failed to include their name and signature on the CCF.

4. Two separate collections were performed on one CCF.

5. The specimen ID numbers on the bottle and on the CCF do not match.

6. The specimen seal on the bottle is broken or shows signs of being tampered with.

7. When the sample makes it to the lab, there is insufficient amount of sample in the primary sample bottle (this could be from leakage during transport, or an insufficient amount of sample being collected).

If any of the above scenarios happen, the lab will deem a Fatal Flaw and the Medical Review Officer (MRO) will report it as "Rejected for Testing" and provide the reason for the sample being rejected.

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Written by John Hawes

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John Hawes is the CCO and co-founder at SureHire Occupational Health Testing. John graduated in 2001 from the University of Alberta with a Bachelor of Science degree in physical therapy. As a former physical therapist, John uses his knowledge of physical therapy and interest in ergonomics and biomechanics to devise fit for work testing.

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