With a new year comes new laws taking effect. While Proposition 64, which legalizes the adult use of marijuana in California, is not technically a new law since it went into effect in November of 2016, recreational sales finally started this month. However, this doesn’t mean that it’s all harmony and good vibes, especially in the workplace. In fact, despite Proposition 64 (formally entitled, “Control, Regulate and Tax Adult Use of Marijuana Act"), not much has changed regarding marijuana in the workplace—Employers can still drug test their employees for marijuana, employees can still be fired, and job applicants can be rejected for using the drug. Though proponents may decry this as unfair, the California Supreme Court dealt with medical marijuana in the workplace nearly ten years ago in Ross v. RagingWire Telecommunications, Inc., 42 Cal. 4th 920, (2008). The plaintiff, in that case, was fired for using medical marijuana, which the employer discovered through a drug test and after the plaintiff gave the company a copy of his physician’s recommendation. The plaintiff said he needed medical marijuana for his chronic back pain. He sued his former employer and claimed that he was fired because of his disability. Yet, the State Supreme Court saw things differently and ruled that employers can legally fire, or not hire, someone due to marijuana use. The Court also found that employers do not have to accommodate an employee’s medical marijuana use even if they have a valid recommendation from a doctor. While this may seem surprising, Proposition 64 explicitly states that it does not change an employer’s right to a drug test or terminate employees. If employers choose to ban marijuana in the workplace, they should have a clear policy that they uniformly enforce. This is especially true for jobs that involve driving or construction, where no-tolerance policies are the norm. Employers who wish to administer drug tests face technological challenges: current drug tests can only check if marijuana is in the system and cannot determine if the user is under the influence of marijuana. Because marijuana can be detected in the body long after consumption and long after the effects have subsided, an employer does not have a precise way to determine if an employee is actually under the influence while at work. Marijuana advocates argue that it is unfair to fire or discipline employees who test positive for marijuana since current testing cannot determine if a worker was actually impaired on the job versus simply having evidence of marijuana in the system from past use. Although current testing technology has not yet provided a precise way to distinguish between on-the-job and off-duty marijuana usage, employers are generally free to determine how they will handle marijuana in the workplace, including setting a zero-tolerance policy, administering drug tests and terminating those who fail. Employers would be wise, however, to make the policy clear to employees in advance. Knowing this, employees should be cautious and try to get a clear answer to their employer’s policy regarding marijuana usage. For now, Californians will have to proceed carefully while navigating this evolving area of the law.