How Can Employers Respond to Laws Legalizing Marijuana?

​Employers are trying to bolster workplace safety as the use of marijuana rises and more states legalize the recreational use of cannabis. (The latest state to do so is Minnesota, effective Aug. 1.) Training to help managers recognize the signs of cannabis use and policies barring the use of cannabis during work hours can help prevent accidents.

The number of post-accident drug tests that came up positive for marijuana grew 204 percent from 2012 to 2022, according to research from Quest Diagnostics, coinciding with a trend of more states legalizing recreational cannabis use. But confirming whether an employee is under the influence of cannabis is tricky, as no drug test detects current cannabis use and state laws vary as to what types of testing are lawful.

Clarify Policies

"Employers should ensure that they have clear policies advising employees that cannabis use during work hours—including meal breaks and rest breaks—is not permitted, and that cannabis use is not permitted on company premises, including in an employee's car in the company parking lot," said Kathryn Russo, an attorney with Jackson Lewis in Melville, N.Y.

Otherwise, employees in states where cannabis is legal may argue they did not have fair notice of the company's expectations, said Jennifer Mora, an attorney with Seyfarth in San Francisco.

"Employees in safety-sensitive jobs should be requested to refrain from marijuana use for at least six to eight hours prior to reporting for work to ensure that they can perform their job duties safely," Russo said.

Provide Manager Training

Even if marijuana testing isn't permitted in a state, employers should ensure their supervisors and managers have been trained to recognize impaired behaviors so they can be addressed before an employee causes an accident, Russo said.

The most common signs of marijuana use include red eyes, the unmistakable aroma on clothing, slow response times, poor coordination, lethargy and increased appetite, said James Reidy, an attorney with Sheehan Phinney Bass & Green in Manchester, N.H. Other symptoms include panic, paranoia, anxiety and hallucinations.

"Many times these symptoms or clues are a departure from the employee's normal appearance or conduct," he said.

State Laws Vary

State laws vary on whether and when cannabis testing of employees is allowed.

As of Aug. 1, Minnesota does not permit cannabis testing for pre-employment purposes or during routine physical examinations unless the job is classified by the employer prior to the testing as safety-sensitive, Russo said. Pre-employment testing is a drug test conducted after a job offer but prior to the start of employment.

Reidy added that in most states, however, employers can test for cannabis as part of post-offer, pre-employment testing, particularly for safety-sensitive positions.

Minnesota defines safety-sensitive to mean that drug or alcohol impairment could threaten the health or safety of the employee or others, Russo noted.

"Minnesota still will permit cannabis testing of any type of employee for reasonable suspicion testing, which includes post-accident testing under Minnesota law," she said.

In Minnesota, an employee may be subjected to a drug or alcohol test when there is reasonable suspicion that the employee at work:

• Is under the influence of alcohol or drugs.
• Violated a written work rule prohibiting the use of alcohol or drugs while operating machinery.
• Sustained a personal injury or caused another person's injury.
• Caused a work-related injury or operated or helped to operate equipment involved in a work-related accident.

"The other common type of drug test that some employers conduct is random testing, which involves putting some or all employees into a random selection pool and periodically making selections for testing," Russo said.

Minnesota requires rehabilitation instead of termination for employees who test positive for marijuana for the first time. Rehabilitation also is required in other states, such as Maine, Rhode Island and Vermont, Russo said. In Iowa, this is true only for positive alcohol tests, not drug tests, she added.

"The employer typically requires the employee to be evaluated for a potential substance abuse problem with a substance abuse professional," Russo said. "If the substance abuse professional determines that the employee does not have a substance abuse problem, the employee returns to work. If the substance abuse professional determines that the employee has a substance abuse problem, then a recommendation for substance abuse treatment is made and the employee must comply before returning to work."

If an employee refuses to participate in the program or fails to successfully complete it, the employer can fire the employee—otherwise the employer must let the employee continue working, Mora said.

Pay attention to applicable state or local law, Russo said. "For example, in New York, no cannabis testing is permitted. In states where cannabis testing is permitted, cannabis testing may be used for reasonable suspicion tests when an employer believes that an employee is impaired at work."

An employer might send an employee for a reasonable suspicion drug test if the employee appears high after returning from lunch or a break, Mora said. But a positive test for cannabis won't prove marijuana use during the break, she noted.

How long residual levels of tetrahydrocannabinol (THC), the psychoactive component of marijuana, remain in the body depends on an individual's marijuana use. The half-life—the amount of time it takes the concentration of THC in the body to decrease by half—for those who infrequently used marijuana is 1.3 days, according to one study. More frequent use showed a half-life of between five and 13 days, reported the American Addiction Centers.

In addition, detection of THC depends on the sample taken—up to 30 days, depending on the frequency of use, in urine tests, which an American Addiction Centers article called the "preferred method of drug testing to detect marijuana use." Detection of THC lasts up to 12 hours in blood tests, up to 24 hours in saliva tests and up to 90 days in hair tests, the article reported.  

The fact that there isn't a current test for marijuana use is why some employers have dropped cannabis testing, Russo said.

Other reasons include the still-thin labor pool and explosion in marijuana use, Reidy added.

"Employers concerned about safety take the position that no use is allowed, regardless of when it occurred," Mora said. "That will not work in jurisdictions like New York; Montana; and Washington, D.C.," which have included cannabis in anti-discrimination laws.

She said some states—such as California, New Jersey and New York—have passed laws making it difficult to ensure safety via a drug-free workplace. "Zero-tolerance policies relating to cannabis are not allowed in some states," Mora said. "Thus, employers concerned about safety should have a strong and legally defensible reasonable suspicion testing program," if state law allows.

Another option—rely on observed impaired behaviors when disciplining, Russo said.