In a recent webinar, a workplace drug screening expert said it's not the changing cannabis laws themselves that are going to end up costing businesses money. Rather, it will be another set of laws that employers might not even consider.

William Judge, co-founder of the Drug Screening Compliance Institute, in his webinar "Marijuana at Work in 2019: What Employers Need to Know," said it will likely be the various state disability laws that will trip up employers when it comes to drug testing for cannabis.

Businesses are within their rights to say they don't want cannabis present in their workplaces. However, trying to restrict the use of medicinal cannabis can also mean inadvertently discriminating against someone with a disability who uses medical cannabis.

Where businesses can get into trouble is with the wording of some states' disabilities laws. In Massachusetts and Nevada, for example, the laws state that employers need to try to accommodate an employee's underlying medical condition or disability. If they use cannabis in a medical capacity to deal with their condition, an employer would technically not be accommodating their underlying condition or disability if they restricted the employee from using medicinal cannabis during off-duty hours.

In a New Jersey court case, for example, a funeral director who was fired because cannabis was detected in a drug test was able to sue his former employer on the basis of the New Jersey Law Against Discrimination rather than the New Jersey Compassionate Use Medical Marijuana Act.

Disability laws can also affect an employer's ability to test for prescription opioids. Unlike cannabis, they are not illegal federally. Even if people have a prescription for cannabis, the fact that it's illegal federally means it's not covered by the Americans With Disabilities Act (ADA). However, prescription opioids are legal and, therefore, covered under the ADA.

If employers try to test for prescription opioids in the workplace, that discriminates against anyone in a non-safety sensitive position who has a prescription for opioids and can get employers in trouble via the ADA and potentially their state disability laws.

Here are a few ways to make sure your business is safe while also in compliance with all the various regulations that govern it. 

1. Study up

By far the most important thing a company can do is be informed of the various rules and regulations that govern drug use and drug testing. This includes federal laws, individual state laws in all the states a company operates in, and regulations passed by the various government agencies that oversee an industry.

A company should stay abreast of both drug laws -- especially new laws pertaining to cannabis -- and disability laws that may also provide employees a window for legal action.

Perhaps most important of all, companies need to pay attention to court decisions, which are the ways a law is interpreted. How judges choose to enact the various laws is extremely important for them.

This is something we are going through at the business I run with my wife. California recently legalized cannabis and we sell drug testing kits and services to businesses, so it's doubly important for us to make sure we are informed not only of our own state's laws but also those across the country. 

2. Write it down

Have a written drug-free workplace policy that includes the company's stance on things like illicit drug use, alcohol use, and the ramifications of using them at work. It's always best to have a written document in place that you can reference when conducting drug tests in the workplace. This will help solidify the company's stance if there are questions raised.

The policy should include the processes involved in drug testing so anyone can look up the procedures to follow if necessary and leave little room for error when conducting drug tests.

Train all your managers and supervisors about the policy and make sure they all understand it completely. 

3. Review and revise

Review and, if necessary, revise your job descriptions and make it clear which positions are considered safety sensitive and what type of drug testing can be expected within those roles.