Employers may continue to ban marijuana use at work and enforce drug free workplace policies. However, most tests detect marijuana in people weeks after their last use, and they cannot determine when users were high or if they used marijuana at work.
Marijuana differs than alcohol because it stays in the typical person's system longer. For example, a user who smoked a joint over the weekend may have a clear urine screen by Monday. However, other users may have traces in their systems up to 30 days while hair tests can detect traces for 90 days.
Companies will need to reexamine their polices and set forth whether all or some marijuana use is unacceptable. They must decide whether testing will be performed during a job application or randomly.
Some businesses have no discretion, however. Under federal law, companies engaged in the transportation business must test their employees. Federal contractors and grant recipients must also have drug-free workplaces. Some employers also keep drug-free workplaces to lower their workers' compensation insurance.
The history following the legalization of medical marijuana in Michigan reveals other potential problems. Few businesses changed their drug policies. Workers had few legal protections if they used the drug for valid therapeutic reasons.
In one case, a federal appeals court ruled against a medical marijuana cardholder from Battle Creek who lost his job at Walmart because he tested positive for using cannabis to treat sinus cancer and a brain tumor. He claimed that he never used marijuana while working, but the court ruled that Michigan's law could not dictate a private employer's actions. However, a state appeals court ruled that medical marijuana users could be eligible for unemployment benefits.
Workers have rights against arbitrary and subjective workplace policies that can lead to wrongful termination and other problems. An attorney can help assure that these rights are protected.