What happens to drug testing if marijuana becomes legal?

The goal of workplace drug testing is to enhance workplace health, safety, and productivity rather than the detection of illegal activity. For this reason, the legalization of marijuana should have little practical impact on workplace drug testing. Most drug testing policies cover prescription and over-the-counter drugs, in addition to the use of alcohol and illegal drugs. As marijuana use increasingly becomes legalized, incorporating the change will be a matter of recategorization of the drug from illegal to legal.

State Laws Regarding Drug Testing for Marijuana Use

Currently, the legalization of recreational or medical marijuana use is being determined on a state by state basis. Over twenty states have passed legislation authorizing the use of medical marijuana. Several states have also authorized the use of marijuana by adults for recreational purposes. These numbers continue to change as additional states address the issue through legislation. At the time of this writing, the use of marijuana remains illegal under federal law.

In those states where legalization has taken effect, some have sought to address the issue of employer drug testing, while others have remained silent. Recent state laws governing legalized marijuana and employee drug testing include laws that prohibit discrimination against someone who is using marijuana for medical treatment and laws that treat drug addiction as a disability. However, even in states that prohibit employers from penalizing an employee who legally uses marijuana, an employee can be disciplined for on the job impairment.

Treatment of Marijuana use under Current Federal Law

At the federal level, regulatory agencies have stated that marijuana continues to be a prohibited substance subject to federal employee drug testing rules and regulations. The Department of Transportation has issued statements regarding both recreational and medicinal marijuana use emphasizing that the DOT’s drug and alcohol testing regulations prohibit the use of marijuana, a Schedule I drug, for any reason. An employer who performs drug testing to comply with the federal drug testing mandate must still test for marijuana use and take disciplinary action against employees who test positive.

What if Marijuana does become Legal on a Federal Level?

If marijuana becomes fully legal for use under both state and federal laws, then federal rules and regulations would most likely treat its use in the say way as the use of alcohol, prescription, or over-the-counter drugs that represent workplace safety hazards.

Marijuana use causes impairment of your short-term memory, motor control, and judgment. Marijuana use is frequently implicated as a cause of motor vehicle accidents and fatalities. A blood THC level of 2 to 5 ng per milliliter (ng/mL) is sufficient to cause detectable impairment. In comparison, the federal cut-off level for a marijuana screening test 50 ng/mL and for a confirmation test the cut-off level is 15 ng/mL. Additionally, studies have found that the memory impairment caused by marijuana use can last for up to seven days after exposure. If you have enough TCH in your system to trigger a positive result to a workplace drug screening test, you are likely impaired. This impairment creates a safety risk for you and a work hazard for your co-workers. Because various substances, both legal and illegal, can cause you to be impaired, state and federal laws address the matter as a safety issue, not a criminal one. An employer may remove an impaired employee from the workplace, regardless of the cause of that impairment.