California Drug Testing Laws for Employers
California has no comprehensive drug testing statute, which leads a lot of employers to the wrong conclusion. Two things do the regulating instead: a constitutional privacy right that applies to private employers, and a cannabis statute that changed what a positive marijuana result can mean.
The Privacy Right Comes First
Article I, section 1 of the California Constitution establishes privacy as an inalienable right, and unlike most constitutional provisions it reaches private employers, not just government. There is no testing statute setting out permitted categories, notice periods, or procedures. Instead, a California testing program is evaluated against whether the intrusion is justified in the circumstances.
The practical consequence is that context carries more weight here than elsewhere. Testing an applicant after a conditional offer sits on far firmer ground than testing a long-serving employee with no particular reason, and safety-sensitive roles are treated differently from desk roles.
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Request a SpecialistGovernment Code 12954, and Why Panels Changed
Effective January 1, 2024, Government Code section 12954 made it unlawful under the Fair Employment and Housing Act to discriminate against someone in hiring, termination, or any term or condition of employment based on either of two things:
- Their use of cannabis off the job and away from the workplace, or
- An employer-required drug screening test that found non-psychoactive cannabis metabolites.
That second point is the one that changes testing mechanics rather than just policy language. A standard urine screen for cannabis detects metabolites, which can remain present long after any impairment has passed. Section 12954 says an employment decision cannot rest on that.
Section 12954(b) separately prohibits asking applicants about prior cannabis use.
Who Is Carved Out
- Building and construction trades employees are excluded from section 12954.
- Positions requiring a federal background investigation or security clearance are excluded.
- Federally mandated testing survives. Subsections (d) and (e) preserve testing required by state or federal law, including as a condition of federal funding or a federal contract.
Those carve-outs are narrower than employers often assume. "Safety-sensitive" in the general sense is not one of them.
What California Employers Are Actually Changing
Most of the work is in three places. The panel, so that cannabis testing targets psychoactive THC rather than resting on metabolite detection. The policy language, which in many companies still describes acting on any positive result. And the application process, where questions about prior cannabis use need removing.
Notably, none of that requires abandoning testing. Pre-employment testing, post-accident testing, and reasonable suspicion testing all remain available. What changed is what a cannabis result by itself can support.
If You Operate Beyond California
This is where national programs break. A single panel applied everywhere is fine in a state like Texas and creates exposure in California. The workable structure is one national program with a California layer, which is the same pattern used for other states with their own rules.
California's largest employment sectors include technology, healthcare, agriculture and food processing, entertainment, transportation and warehousing, and construction. That last one matters here, because construction trades sit inside the statute's carve-out.
Common questions
Can we still drug test employees in California?
Yes. California has no statute prohibiting employer drug testing generally. What it has is a constitutional privacy right that applies to private employers and a specific cannabis statute, Government Code section 12954, that limits what you can test for and act on.
What exactly does Government Code 12954 prohibit?
It makes it unlawful under the Fair Employment and Housing Act to discriminate against a person based on their use of cannabis off the job and away from the workplace, and to act on a drug screening test that found only non-psychoactive cannabis metabolites. Subsection (b) also bars asking applicants about prior cannabis use. It took effect January 1, 2024.
Does that mean we cannot test for marijuana at all?
Not quite, and the distinction matters. The restriction is aimed at tests that detect non-psychoactive metabolites, which indicate past use rather than current impairment. Testing methods that identify psychoactive THC are treated differently. In practice most California employers reviewing their program are changing the test method or the panel rather than removing cannabis from it.
Are there exceptions?
Yes. Section 12954 does not apply to employees in the building and construction trades, or to positions requiring a federal background investigation or security clearance. Subsections (d) and (e) also preserve federally mandated testing and drug-free workplace requirements tied to federal funding or contracts.
Does California require a written policy or advance notice?
No California statute we reviewed imposes either on private employers. Section 12954 contains no policy or notice provision. That said, given the privacy analysis California courts apply, a clear written policy that explains what is tested and why is more valuable here than in states that spell out a script.
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Sources and review
- Cal. Gov. Code 12954 (California Legislative Information)
- Cal. Const. art. I, Sec. 1 (inalienable right of privacy)
- Cal. Health & Safety Code 11362.45 (limitations of Proposition 64)
- Cal. Health & Safety Code 11362.1 (adult personal use of cannabis)
This page is general information about employer drug testing, not legal advice. Drug testing rules differ by state and by industry. Check with your own counsel before setting or changing a testing policy.