Last Tuesday, Michigan voters approved a ballot initiative legalizing the sale and use of recreational marijuana. The next morning, my phone started ringing with calls from CFOs and HR Managers trying to figure out how the new law will impact existing workplace drug and alcohol policies. My answer? Stay the course … for now.

Just because marijuana will be legal for recreational use, it doesn’t necessarily follow that employers need to allow it, or its effects, in the workplace. Like alcohol, marijuana can adversely impact job performance, and, for that reason, companies need to restrict it at work.

Unlike alcohol, marijuana can be detected in the body for weeks after it was last ingested. And that will be the rub. Companies with random drug testing will likely face an increase in complaints of unfair treatment by employees claiming their recreational use was off the clock and had no lasting impact on their workplace sobriety, notwithstanding trace amounts in their system.

The real challenge will not be complaints from recreational users. Even if they feel they are being treated unfairly, the new law does not compel accommodation. But an old law might. Remember that Michigan already has medical marijuana on the books. And state and federal law compel employers to provide reasonable accommodations to workers with medical disabilities. When someone with a prescription uses marijuana for pain management, for example, and that person reports to work no longer under the influence but with the drug still detectable by screening, would a deviation from the zero-tolerance policy be a reasonable accommodation?

Tread cautiously in this area, stay tuned for updates, and reach out for help as needed.