Dive Brief:

• "[T]here is no level of cannabis use that is safe or acceptable for employees who work in safety sensitive positions," according to a National Safety Council (NSC) position statement. For this reason, the NSC — a nongovernmental nonprofit — said it supports moving people who are using cannabis for medical purposes to non-safety sensitive positions.
• While the amount of THC detectable in a person's body does not directly correlate with the level of impairment, said the NSC, research clearly indicates that cannabis affects psychomotor skills and cognitive ability. The NSC said it hopes to increase its involvement in policy discussions about cannabis impairment and "provide guidance for employers as they navigate changing cannabis laws."
• The NSC's position paper cited a study from the National Institute on Drug Abuse, which found that employees who tested positive for cannabis had 55% more industrial incidents, 85% more injuries and 75% greater absenteeism compared to employees who tested negative.

Dive Insight:

The position paper pointed out that cannabis remains illegal at the federal level, even though there are laws that legalize it in some form in many states.

This discrepancy presents obvious enforcement challenges for employers, especially when it comes to employees using medical marijuana for an impairment. And, as the NSC position paper noted, THC levels in the body don't always correlate with the actual level of impairment like, for example, blood alcohol levels show.

Experts recommend that employers get familiar with any medical marijuana laws that apply to their particular jurisdiction, review potentially problematic "zero tolerance" drug policies and try to focus more on unacceptable behaviors (such as performance, conduct or safety issues) rather than drug test results.

Linda Hollinshead, partner at Duane Morris LLP, previously told HR Dive that employers had been winning state-law cases brought by employees who were fired (or not hired) due to marijuana usage, but a few recent cases have been decided in favor of employees. While it's too soon to say whether these cases are isolated results or represent a broader trend, employers should exercise caution with their policies and practices and consult counsel as needed.