Cannabis in the Workplace FAQs

Frequently Asked Questions

Can employers prohibit cannabis use during work hours?

Yes, similar to alcohol, employers may regulate use or impacts of cannabis use in the workplace. RCW 69.50.445 prohibits personal use of cannabis "in view of the general public or in a public place." In addition, employers may have workplace policies prohibiting cannabis use or being under the influence of cannabis while working.

Can employers continue to test for cannabis?

Yes. Although Initiative I-502, codified in chapter 69.50 RCW, does not address the topic of workplace drug testing, it is our understanding that employers may still conduct drug testing in accordance with their legally adopted policies. Since cannabis remains illegal under federal law, institutions (including local governments) that receive federal funds are still required to follow the federal Drug-Free Workplace Act, including its testing program requirements.

Similar to alcohol, employers may require testing, may impose discipline for policy violations, and may prohibit use in the workplace. Employers should make sure that their personnel policies are up to date and include reference to legalized cannabis. Employers should consult with their city, agency, or other legal representatives.

How does the law affect CDL holders?

Commercial Driver License (CDL) holders are regulated by the state's Department of Licensing (DOL), which follows federal regulations. Where federal Drug-Free Workplace Act and U.S. Department of Transportation (DOT) standards apply, there is zero tolerance for cannabis use, including medicinal use.

What is the legal limit of THC for blood tests? 

In Washington State five nanograms per milliliter (5 ng/ml) is the legal THC limit for driving impairment as set forth in RCW 46.61.502(1)(b) and RCW 46.61.506. This is the per se level of impairment for someone under the influence of cannabis as measured by a blood test designed to detect "active metabolites." State v. Fraser (2022) upheld the 5ng/ml legal limit in state law.

CDL holders are regulated by the DOL, which follows federal regulations. RCW 46.25.120 provides that “any measurable amount of THC concentration” results in disqualification of a driver with a CDL. See also, DOT Rule 49 CFR Part 40 Section 40.87.

What about off-duty cannabis consumption?

Washington public employers have a legal basis to discipline or discharge employees who test positive for cannabis if such action is consistent with their respective contracts, policies, and past disciplinary actions. However, to date there is no further legislation or case law on the issue of whether discharge for off-duty recreational cannabis use violates public policy. See below for reference to Roe v. TeleTech Customer Care Mgmt (2011) and medicinal cannabis.

What about medical cannabis use in the workplace?

There is not a legal right to use medical cannabis in the workplace. An employer may have a policy that requires all new employees to have a negative drug test result even when employees are prescribed medical cannabis. See, for example, Roe v. TeleTech Customer Care Mgmt (2011), in which the court held the state Medical Use of Marijuana Act (MUMA) did not protect employees from discharge for medicinal cannabis use. The plaintiff was authorized to use cannabis medicinally but had her job offer rescinded after a positive drug test.

Recommended Resources

• U.S. Substance Abuse and Mental Health Services Administration: Federal Contractors and Grantees - Drug-Free Workplace Programs – Discusses requirements that apply to agencies receiving a federal contract of $100,000 or more, or a federal grant of any size. 
• Washington State Liquor and Cannabis Board – Provides additional FAQs, fact sheets, and other useful information.