Cannabis Testing in the Workplace

Michigan law allows employers to test applicants and employees for cannabis.

Know the cannabis facts and stay employed.

Your job is more important than cannabis.

WHAT? Marijuana is legal here in Michigan!

It’s true—just like alcohol—you can buy cannabis in Michigan if you are 21 years or older, but employers operate with their own rules and policies. For example, if they want to be a “drug-free workplace,” they can mandate pre-employment and periodic or random drug testing of some or all employees.

Most private employers are not required by law to test for alcohol or drug use; it just happens that some do and others don’t.

Companies with large transportation operations or those in federally regulated safety-sensitive industries are required to conduct drug screens. For example, those businesses in the trucking industry, in aviation or mass transit, including those companies that hold contracts with the Department of Defense or NASA, are required to test prospective employees for alcohol and drug use.

Sometimes large employers, especially those that hire hundreds of people every year due to turnover, growth and retirement, conduct drug screens of all potential employees as part of the routine hiring process.

Here’s the sticky issue with cannabis and workplace drug testing.

Unlike other substances, like those listed above, cannabis remains in the human body for a significant period of time.


For infrequent or light consumers, it can be just a few days for the THC to disappear. For others who consume on a daily basis, it can be a month or more until the body shows no signs of THC.

How long THC sticks with you depends on your weight (especially your body mass), the amount of consumption you do or have done, and your physical activity level. It also depends on the test—urine screens are less powerful than a hair test. Hair tests can detect THC use up to 90 days before the sample being taken.

FAQ’s About Cannabis Testing in the Workplace

Why Do Employers Do Drug Tests?
Other than for cultural reasons, that is, maintaining a drug-free workplace, there are a few different reasons businesses do drug tests.

Many states offer employers a discount on workers’ compensation insurance premiums if they have policies to maintain a drug-free workplace, and this may include drug testing all job applicants.

If an intoxicated employee harms someone on the job, the employer could be held legally liable for the injuries incurred. In addition, workplace drug and alcohol use may also violate OSHA and state occupational safety laws.

Can I Refuse a Drug Screen?

You have the right to refuse a drug test, and in turn, the employer has the right to refuse to offer you a job. Now, if you’ve found your ideal job—this isn’t what you want to be doing.

If you are in the market for a job, the best thing to do is stop consuming cannabis to pass the test. If you’re a medical marijuana patient, the best time to discuss this with the potential employer is during the first interview. It may be that the company does not require a drug screen, and you’ll be in the clear. If you’re willing to talk about your medical condition and use of cannabis, you might find an understanding company that will accommodate you. If not, it might be best to move on and find another opportunity.

Keep in mind that it costs an employer to interview and hire a candidate, and the further you move down the interview process, the more difficult it will be to walk away from the opportunity.

So think before you toke!

What About Medical Marijuana?
As of 2021, 36 states allow residents to use marijuana for medical purposes. These medical marijuana states, including Michigan, require the patient to have a written doctor’s authorization to consume the cannabis. If a patient meets the medical marijuana criteria, s/he cannot be prosecuted under state law for “crimes” relating to the use, possession, or cultivation of a certain amount of marijuana.

If you’re living in Michigan and have a valid prescription for marijuana, you might wonder if an employer can refuse to hire you based on a positive drug screen for this legally prescribed drug. In most states, and in most cases, the answer is yes.
According to the Society for Human Resource Management, “The California Supreme Court has ruled that the state’s medical marijuana law applies only to criminal prosecution, not to the workplace. Likewise, the Colorado Supreme Court has held that an employer may fire an employee for off-duty use of medical marijuana, even though the use was lawful under Colorado state law.”

A few states and cities have recently passed specific laws prohibiting employers from discriminating against an employee or applicant for the lawful use of medical marijuana or requiring an employer to reasonably accommodate such employees at the workplace, but Michigan is not one of them.