California employers have 15 months to figure out the best way to determine if employees are impaired and trying to do their jobs after smoking marijuana or eating cannabis-infused snacks.

Attorneys and scientists say there’s currently no way to do that accurately.

“None of these workforce drug tests are able to assess impairment,” said Barry Sample, senior science consultant for Quest Diagnostics Inc.’s Employer Solutions franchise.

California Gov. Gavin Newsom (D) on Sunday signed a measure (A.B. 2188) that prohibits employers from discriminating against workers who use cannabis in their off-work hours. The new law goes in effect Jan. 1, 2024.

Standard drug tests detect metabolites in urine and hair, the result of the breakdown of tetrahydrocannabinol (THC) molecules that can stay in one’s system for several days or, in some cases, weeks.

Because the THC detected in these tests can’t determine if a marijuana user’s brain function was impaired on the job, employers can no longer rely on them to settle the cause of an workplace accident, for example. The tests can still be used before a worker is hired, for construction jobs, and for positions that require federal oversight.

Supporters of the new mandate expect examinations to shift toward saliva tests, which can pick up THC ingested in the past 24 to 36 hours. That’s a much narrower detection window...

Read Full Story: https://news.bloomberglaw.com/daily-labor-report/california-bosses-must-prove...