1. When should we test?

That depends on what your ultimate objective is. Are you seeking to screen out potential hires who use drugs? Are you seeking to deter drug use among all employees? Do you want the ability to test employees who you suspect are using drugs in the workplace? Do you want to know whether drug use contributes to on-the-job injuries?

The way you answer those questions will determine how you should test your employees. Among other options, employers can consider pre-employment testing, random or periodic testing, and post-injury testing.

2. How should we test?

Employers have several testing methods to choose from. Urine testing is the mostly frequently used method; it can detect a variety of drugs in an employee’s system and it’s inexpensive and easy to administer. But other methods—including oral/saliva and hair testing—may be more appropriate for some employers and in certain circumstances. For example, hair testing can detect drug use for up to 90 days, which may make it more attractive to employers performing pre-employment testing.

3. How do we stay compliant?

Determining when and how to test should be considered in the larger context of ensuring legal and regulatory compliance of overall zero-tolerance policies. Your labor and employment counsel should help you make sure that your approach to preventing drug use complies with all applicable federal, state and local laws and regulations. Among other things, it’s important that you have a clearly written policy that explains to employees the consequences of a positive test result, and that your policies specifically address medical and recreational use of marijuana—especially in states where such use has been legalized.

As more states legalize marijuana for medical or recreational use, or both, employers may find maintaining safe workplaces more challenging—especially while trying to balance employees’ individual rights. Starting with these three key questions should at least put you on a path toward meeting those challenges.

Editor's note: Tom Ryan is a managing director and Market Research Leader in Marsh’s Workers’ Compensation Center of Excellence. He is responsible for developing market research, insight, and other content on emerging issues, trends, regulatory, and other changes that affect the workers’ compensation market. This article was first published on Marsh’s website.