Hemp seeds, THC, False Positive Tests and Intransigence.
This is sad, cautionary, true story. It is intended to highlight a little-known hazard of hemp-seed products. The names the people and organisations involved have been changed.
In March 2009, a woman called Anna got in touch. She had lost her job, she claimed, because she had failed a random urine test at work. She had tested positive for cannabis metabolites. Her employer, a large national company with a strict drugs policy and testing regime, had dismissed her. With the help of her Union Rep she planned to challenge the dismissal. Could, she asked, we help?
She was adamant that she had not used any illict forms of cannabis. She was however a regular user of Hemp Seed Oil, a legal and highly regarded dietary therapy. Hemp Seed Oil is reputedly high in Essential Fatty Acids and Omega 3,6 and 9 EFAs. Could this have been the cause of her positive test result?
Anna had been using Hemp Seed Oil from a reputable herbal therapies supplier. They said that the amount of THC in their product was 6 ppm (parts per million). This alone would come as a suprise to most people, who assume that there is simply no THC in seeds. However, in cropping and processing, resin can adhere to the outside of the seeds. While careful washing and processing will remove the majority of this THC, a small amount will survive the processing and get incorporated in to the final product, albeit at very low doses. However, the website of the Herbal Remedies supplier makes no mention of this, even after Anna's experience, of which the company are aware.
Anna was taking up to six table-spoons of Hemp Seed oil a day - some 60ml/day at 6ppm THC. This would mean she was consuming around .35mg THC/day. This is well below a psychoactive dose, but would it be enough to trigger a positive urine result.
There is very little robust research on the subject of THC levels from use of Hemp Seed. Much of the research has been funded by manufacturers of Hemp Seed Oil, keen to disprove that Hemp Seed Oil could result in positive THC results. Attendant negative publicity would have damaged the Hemp Seed Oil market, something manufacturers were keen to avoid.
Fortunately one piece of robust research had addressed this problem, in a paper snappily entitled "Urinary Cannabinoid Detection Times after Controlled Oral Administration of 9-Tetrahydrocannabinol to Humans" Clinical Chemistry. 2003;49:1114-1124.
This paper reported that "The 0.39 and 0.47 mg/day doses produced maximum urine THCCOOH concentrations (cmax) of 7.3–38.2 and 5.4–31 µg/L, respectively, with mean times to the highest THCCOOH concentration (tmax) of 99.9 and 85.9 h, respectively."
The cut-off for a positive result used by the Labs used by Anna, and by her employers, was 15 µg/L, a level that Anna had just exceeded. But based on the Journal of Clinical Chemistry, a dose range of 0.39mg/day (a fraction higher than Anna's 0.35mg/day) produced results that ranged from 7.3-38.3 µg/L. At the high end this means the results would be more than double the cut-off used by her employees.
Based on these results it seemed very apparent that the Hemp Seeds could well have caused the positive results, especially when at high doses for a sustained period of time. In Anna's case this was more than six months: far longer that the time frame used in the clinical trials.
These results were submitted to the Appeals Board on Anna's behalf. We were optimistic that the Appeal would be successful based on the evidence submitted which was robust and scientific.
Amazingly, the appeal was not allowed. Her Employees didn't reject the evidence about the test results. Instead the company used their policy demand that "any medication which may affect a persons ability to undertake their duties must be disclosed at the earliest oppertunity." Anna hadn't disclosed her use of Hemp Oil. Why should she have done so? Nothing she had been told by the herbal supplier suggested that it would produce a positive drug result. And the THC levels present in the Oil wouldn't have affected Anna's ability to undertake her duties. So there was no need and no reason for her to have notified her employee of her Hemp Seed Oil usage.
Unfortunately her employees didn't see it this way; they argued that the Hemp Seed Oil, which resulted in a positive drug test, may have affected her ability to do her job, and so should have been disclosed to her employees at the earliest opportunity. As this hadn't happened, the dismissal was upheld.
As a result the woman in question lost a job that she enjoyed, and entered unemployment thanks to a flawed drug testing regime and an inflexible drugs policy.
I was furious on Anna's behalf. Her employer's inflexibility was astounding and an appeal to an Industrial Tribunal for unfair dismissal seemed the only way forward.
And at this point Anna taught me an important lesson. She decided that she wasn't going to let battling with her former employees ruin her life. After deciding not to appeal she wrote saying "So, now I can concentrate on finding a wonderful new job and of course carry on enjoying the life of a lady of leisure going for long summer walks and sitting in the garden reading long novels!"
Frankly I was blown away by Anna's ability to overcome the injustice and move on. So following her lead I have tried to do the same rather than raging on. But her story still needs to be shared. Because there may be other people who are using Hemp Seed Oil at risk of false positives. And there are still manufacturers of Hemp Seed Oil that don't warn there products can cause a positive drug test result; and there are Testing Labs that will swear blind that the positive test results and cut-offs could only come from cannabis abuse when this is just not the case. And there may be other employers who share the inflexibility and intransigence of Anna's.
On which note if, perchance, Anna's former employeres read this article, I hope that they will spare a moment for the wonderful person that they sacked, and ponder the stupidity of a policy that can't flex enough to cope with an unforseen situation like this in a sensible and humane way.