Marijuana drug tests can suggest a window of time in which a person may have consumed marijuana, but they cannot measure a person’s active intoxication or level of impairment. They also cannot establish how often or how much marijuana a person uses or whether they have an addiction.
Marijuana drug testing is used in a wide variety of contexts, such as public and private workplaces, hospitals and addiction treatment centers, highway safety enforcement, and K-12 schools. A person may be tested as a condition of employment, parole or probation, receiving public assistance, or maintaining custody of their children. Therefore, the results of a marijuana test can bear massive consequences on the course of a person’s life.
Marijuana prohibition has severely limited empirical research on drug testing and methods of evaluating drug-induced impairment. We simply do not yet have good testing technologies to evaluate impairment. And yet, zero-tolerance drug-free workplace policies continue to impose harsh consequences for people who test positive for marijuana, without also determining whether or not an employee’s job performance was negatively impacted.
Federal marijuana decriminalization presents the opportunity to improve research on marijuana and marijuana drug testing. Eliminating testing for positions where impairment does not pose a threat to safety and ending zero-tolerance policies will promote a better workplace for all employees. Workplaces must accommodate medical marijuana patients, and safety-sensitive workplaces should develop minimally invasive and evidence-based drug testing policies that approach drug use with honesty and compassion.