Why Drug Testing for Cannabis Doesn’t Work

Research shows that no blood, saliva, urine, or breathalyzer analysis can ascertain whether a person who has used cannabis is actually impaired, and that there is no level of THC in blood or saliva that can discriminate between an impaired and unimpaired person.

Now that cannabis is rapidly becoming legal across the country, law enforcement and employers are in a difficult position regarding its use.  There are laws against driving while under the influence of alcohol or drugs.  Employers may ban illegal drugs. But available drug tests to detect cannabis are ineffective for several reasons.

Standard drug tests currently used by law enforcement and employers can detect ∆9-tetrahydrocannabinol (THC), the main psychoactive chemical in cannabis, by analyzing bodily fluids. These standard drug tests are:

  1. Invasive – you must gather a sample of whatever you are going to test: urine, saliva, or blood.
  2. Inconvenient – you need trained personnel and equipment to gather the sample and likely you must travel for the test.
  3. Slow – results can take hours or days.
  4. Expensive – the average cost is approximately $38.00 per test.
  5. Inaccurate – THC levels remain elevated long after impairment.

The most significant problem with current standard drug tests is accuracy.  Research shows unequivocally that no blood, saliva, urine, or breathalyzer analysis can ascertain whether a person who has used cannabis is actually impaired. There is no level of THC in blood or saliva that can discriminate between an impaired and unimpaired person. Why is this the case?  THC is stored in body fat and dissipates through the bloodstream over a long period of time. This means that people whose most recent cannabis was several days or even a few weeks ago may still have THC in their body but show no evidence of cognitive or motor impairment.


Why Does Cannabis Stay in Your System Longer than Other Drugs?*

Cannabis’s intoxicating effects generally peak within 2 hours after consumption, then fade away within 8 hours, depending on your mode of ingestion. This means that the bowl you smoked on a Friday evening will be a distant memory by the time you return to work on Monday. However, when the cannabinoid tetrahydrocannabinol (THC) is broken down, it creates non-active metabolites (THC-COOH) that stay in your system much longer. While these non-active metabolites don’t give you any kind of psychoactive effect, they are the “evidence” of cannabis use that urine drug tests look for. Depending on how frequently you use cannabis, these metabolites can be detected for several weeks or even months after consumption.

Other drugs like cocaine, amphetamines and opiates flush out of the body much faster, within a matter of 1-4 days. Alcohol also quickly exits the system, often within hours.


Why is cannabis different?

Cannabinoids like THC are fat-soluble, with their non-active metabolites accumulating in fat cells. These metabolites are slowly flushed out via urine over a longer timeframe when compared to water-soluble substances that pass through the body without making a stop in fat cells.

When thinking about workplace drug testing, it doesn’t seem fair that someone could either lose a job or an offer due to a positive cannabis drug test, especially in a state where cannabis use is fully legal and very likely happened off the clock. But until employers change their policies or the laws change, drug testing will remain a reality for many workers.

If the goal of drug testing is for the sake of safety, then drug testing for cannabis is ineffective since someone may have legally used cannabis at their home, and then sometime later, when they are not affected by it, “fail” a drug test.

The courts are taking note. In 2019, a federal district judge in Arizona ruled that Wal-Mart discriminated against a worker who had a state-issued medical marijuana card when it fired her after a positive drug test, but without any evidence that she “used, possessed, or was impaired by marijuana” while at work [Whitmire v. Wal-Mart Stores Inc., 2019 WL 479842 (D. Ariz. Feb. 7, 2019)]. Likewise, a state judge in Oklahoma ruled that because a positive drug test did not prove marijuana use had caused a worker’s accident, he was eligible for workers’ compensation benefits [Rose v. Berry Plastics Corp. et al., 2019 OK Civ. App. 55 (Ok. Civ. Ct. App. Oct. 16, 2019)].

Druid App Impairment Testing offers a solution

Increasing legalization of cannabis, combined with the problems inherent in current drug testing, is the precise reason Impairment Science developed the Druid app. This app is a convenient and inexpensive test to determine “fit for duty” from any cause of impairment. Detecting impairment can protect public, corporate, and institutional safety, and it doesn’t matter what the cause of the impairment is. 

*excerpted from this post https://leaf411.org/cannabis-cbd-hemp-and-workplace-drug-testing/  Reviewed by Katherine Golden, RN. Written by Denise Gonzalez-Walke.

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