Six years after California legalized cannabis for adult use, Gov. Gavin Newsom signed new legislation protecting Golden State employees' off-duty cannabis use. That makes California the latest in a series of cities and states to move to protect employees as cannabis legalization spreads across the U.S.

"For too many Californians, the promise of cannabis legalization remains out of reach," Newsom said in a statement. "These measures build on the important strides our state has made toward this goal, but much work remains to build an equitable, safe and sustainable legal cannabis industry."

California Assembly Bill 2188, which will go into effect on Jan. 1, 2024, prevents employers from discriminating against a person during hiring, firing, or employment "if the discrimination is based upon the person's use of cannabis off the job and away from the workplace." 

Although the bill permits employers to issue pre-employment drug screenings, they are not allowed to discriminate in hiring based on whether or not non-psychoactive cannabis metabolites show up in an employee's hair, urine, or blood. Cannabis metabolites aren't detectable in urine until about 60 minutes to four hours after cannabis consumption. And they remain detectable for as little as three days to as many as 30 days after consumption, depending on an individual's metabolism and frequency of use, according to Mayo Clinic Laboratories. As a result, the presence of metabolites is a better indicator of whether an individual has consumed within the last few days or weeks, rather than whether an employee is currently intoxicated.

"As science has improved, employers now have access to multiple types of tests that do not rely on the presence of nonpsychoactive cannabis metabolites. These alternative tests include impairment tests, which measure an individual employee against their own baseline performance and tests that identify the presence of THC in an individual's bodily fluids," the bill reads.

Karson Humiston, CEO of cannabis staffing agency Vangst, applauded the bill but questioned the reliability of tests that do not rely on cannabis metabolites.

"We see this law as a positive step forward in destigmatizing the adult use of cannabis, however, there are still some grey areas for employers," Humison wrote in an email. "For one, current tests cannot accurately determine the level of impairment from cannabis as they can from alcohol, it is also difficult to tell what time a person consumed."

She also encouraged employers to protect themselves by including "explicit contractual language outlining when an employee could or could not be at risk of termination due to impairment from cannabis consumption."

Certain types of employees are exempted from the bill's provisions, including those in construction and those who require federal clearance or background checks. The bill also specifies that employers still have a right to maintain a drug- and alcohol-free workplace and that employees are not permitted to use on the job. 

California is not the first state to enact protections for employees who choose to use legal cannabis, but it remains one of the few. Connecticut, Montana, Nevada, New Jersey, New York, and Rhode Island have each implemented some form of protections for adult-use cannabis, according to NORML. A number of cities including Atlanta, New York City, Philadelphia, Washington, DC, and others similarly protect various employees.

These policies, however, are not identical. Given the federally illegal status of cannabis and the absence of a broader policy governing employment and consumption on the national level, companies have been forced to navigate the patchwork of state laws. Some, like Amazon in 2021, announced broad policy changes protecting their employees. 

"We hope that other employers will join us, and that policymakers will act swiftly to pass this law," then-CEO of Amazon Worldwide Consumer Dave Clark wrote in a blogpost at the time.