California Marijuana Drug Testing Laws: What Employers Need to Know

For California employers building or updating a workplace drug testing program, marijuana is now the most legally constrained substance to screen for in the state. Two laws, Assembly Bill 2188 and Senate Bill 700, took effect on January 1, 2024, and together they fundamentally changed which marijuana tests California employers can rely on and what employers can ask job applicants about cannabis use. The California Civil Rights Department now treats off-duty cannabis use as a protected category under the Fair Employment and Housing Act.

The short version: traditional urine and hair tests for marijuana metabolites can no longer be the basis for hiring or disciplinary decisions in most California workplaces. Employers can still test for marijuana, and they can still maintain drug-free workplaces, but the testing method must detect psychoactive THC rather than non-psychoactive metabolites. For most California employers, that pushes practical screening toward oral fluid testing, impairment-based assessments, or limited use cases that fall under one of the law's narrow exemptions.

What AB 2188 actually says

AB 2188 added Section 12954 to the California Government Code. It makes it unlawful for an employer to discriminate against a person in hiring, termination, or any term or condition of employment based on either of two things:

• The person's use of cannabis off the job and away from the workplace
• An employer-required drug screening test that found the person to have non-psychoactive cannabis metabolites in their hair, blood, urine, or other bodily fluids

The California Legislature's findings written into the bill are unusually direct. The Legislature stated that most existing marijuana tests detect non-psychoactive metabolites that have no correlation to impairment on the job, and noted that as testing science has improved, alternatives now exist that screen for active THC or measure actual impairment. That legislative finding is what the law is built on, and it explains why urine testing for marijuana is essentially off the table for adverse employment action in California.

According to attorneys at Jackson Lewis, AB 2188 does not permit employers to conduct marijuana drug testing unless the test detects only the psychoactive components of marijuana — that is, only current impairment. The firm's analysis explicitly notes that urine testing does not comply with the law for adverse-action purposes.

What SB 700 added

Signed by Governor Newsom on October 7, 2023, SB 700 further amended the Fair Employment and Housing Act. Effective the same day as AB 2188, SB 700 makes it unlawful for an employer to request information from a job applicant relating to the applicant's prior use of cannabis.

Practically, this means California employers cannot:

• Ask about cannabis use on a job application
• Ask about cannabis use during a job interview
• Use information about prior cannabis use obtained from a criminal background check, unless the employer is otherwise permitted to consider that information under California's Fair Chance Law or another state or federal law

According to the California Chamber of Commerce, the SB 700 prohibition is broad and the law's exceptions are narrow. Employers reviewing application forms, interview scripts, and background-check workflows in California should treat any pre-employment cannabis inquiry as a compliance risk.

Pre-employment testing in California after AB 2188 and SB 700

Pre-employment drug testing for marijuana is not banned outright in California. The law specifically preserves the right of employers to conduct scientifically valid pre-employment drug screening through methods that do not screen for non-psychoactive cannabis metabolites. The law's intent is not to stop testing — it is to push employers toward testing methods that measure recent use rather than weeks-old metabolite presence.

For California employers, this changes the practical pre-employment workflow:

• Urine pre-employment testing for marijuana metabolites generally cannot be the basis for rescinding a job offer. According to attorney guidance from CDF Labor Law, employers should assume urine and hair results are insufficient to establish impairment for most employment decisions unless a statutory exception applies.
• Oral fluid testing is positioned as the most practical compliant option for many California employers, because oral fluid primarily detects parent THC at the time of collection rather than long-stored metabolites. This is also why California staffing firms have shifted toward oral fluid for cannabis screening since 2024.
• Pre-employment testing for non-cannabis substances — opioids, cocaine, amphetamines, and so on — is not affected by AB 2188 or SB 700. Many California employers now run a hybrid program that uses urine testing for those analytes and oral fluid testing where cannabis screening is required.
• The pre-employment test must be administered after a conditional offer of employment under longstanding California privacy law, regardless of substance.

Random testing in California

California has long taken a restrictive view of random drug testing in non-safety-sensitive roles. State courts have generally held suspicionless random testing of non-safety-sensitive employees to be a violation of the California Constitution's right to privacy, separate from anything AB 2188 added. AB 2188 does not change that underlying restriction; it adds a layer specifically about marijuana.

For California employers running or considering a random testing program:

• Non-safety-sensitive random testing is generally not defensible in California, regardless of substance, unless the role meets a high standard for justification.
• Safety-sensitive random testing is defensible when the role involves clear public-safety risk, but the marijuana-specific testing method still must comply with AB 2188 — meaning oral fluid or impairment-based assessment for the THC analyte, even in safety-sensitive contexts that are not federally regulated.
• DOT-regulated random testing continues under federal rules and is exempt from AB 2188 (covered below).

Reasonable suspicion and post-accident testing

AB 2188 does not prohibit California employers from conducting reasonable-suspicion or post-accident testing. It restricts which test results can support an adverse employment decision for marijuana. Documented observations of impairment by a trained supervisor, paired with a compliant test, remain a defensible path.

The practical workflow for reasonable suspicion in California now looks like:

• Trained supervisor documents specific, observable behaviors suggesting impairment
• Employer conducts an oral fluid or impairment-based test as the marijuana component
• Adverse action, if taken, is supported by the documentation and the test result, not by the test alone

Post-accident testing follows the same logic. Employers in industries not exempt from AB 2188 should not rely on a urine-only post-accident workflow if marijuana is part of the panel.

Exemptions: where AB 2188 does not apply

AB 2188 contains three narrow but important exemptions where employers may continue to test for marijuana under traditional methods:

Building and construction trades

The law does not apply to employees in the building and construction trades. According to a Jackson Lewis analysis, the statute does not define what counts as the "building and construction trades," which leaves the exemption broad on its face but uncertain in application. Employers who believe they fall within this exemption — general contractors, subcontractors, electrical and plumbing trades, public works, and similar — are encouraged to consult counsel before assuming the exemption covers their workforce.

Federal background investigation or security clearance positions

Applicants and employees in positions requiring a federal background investigation or security clearance under Department of Defense regulations or equivalent federal agency rules are exempt. This covers federal contractors, defense industry employers, and roles tied to federal security frameworks.

Positions where federal law requires testing

AB 2188 does not preempt federal laws or regulations requiring drug testing as a condition of employment, federal funding, federal licensing, or a federal contract. The most consequential federal framework here is DOT-regulated testing under 49 CFR Part 40, which governs commercial drivers, transit workers, pilots, rail workers, and other safety-sensitive transportation positions. DOT testing rules continue unchanged.

A California employer running a DOT program for some employees and a non-DOT program for others must operate two parallel testing frameworks: federal rules for DOT roles, AB 2188-compliant rules for everyone else.

What about THC cutoff levels in California?

California law does not set its own THC cutoff levels for workplace drug testing. The cutoff levels that apply to California testing are the same federal SAMHSA cutoffs that apply nationally:

• Urine THC immunoassay screening: 50 ng/mL initial cutoff
• Urine THC confirmatory testing (GC-MS or LC-MS/MS): 15 ng/mL
• Oral fluid THC initial screening: 4 ng/mL
• Oral fluid THC confirmatory: 2 ng/mL

The California-specific question is not what the cutoff is — it is what the employer can legally do with a positive result. AB 2188 means a positive urine THC result above the SAMHSA cutoff cannot be the sole basis for adverse action against most California employees, even though the result is technically valid. A positive oral fluid THC result above the SAMHSA cutoff is more defensible because it indicates recent use, which aligns with the law's focus on impairment.

This is the most commonly misunderstood part of the California framework: the cutoffs themselves did not change. What changed is the legal weight an employer can give to a positive metabolite result.

Maintaining a drug-free workplace under AB 2188

AB 2188 explicitly preserves the employer's right to maintain a drug- and alcohol-free workplace under California Health and Safety Code Section 11362.45. The law states that nothing in it permits an employee to possess, be impaired by, or use cannabis on the job.

For California employers, this means:

• Workplace policies prohibiting cannabis use, possession, or impairment on the job remain enforceable
• An employee impaired at work can still be disciplined or terminated, supported by documented observations and a compliant test
• Drug-free workplace certifications required for federal funding or contracts continue to apply
• The law does not require employers to accommodate cannabis use, even by medical cannabis cardholders, in safety-sensitive contexts

The shift is in method, not in policy intent. California employers can still run zero-tolerance programs; they just cannot rely on metabolite urine tests alone to enforce them.

Best practical approach for California employers

For most California employers building a defensible workplace drug testing program in 2026, a hybrid approach makes the most sense:

Use rapid oral fluid testing for the THC component of any panel, paired with urine testing for non-cannabis analytes (cocaine, opioids, amphetamines, and so on). This combination preserves the employer's ability to screen for marijuana in compliance with AB 2188, maintains the validity of urine testing for substances not affected by the law, and gives operations and HR teams a clear, repeatable workflow.

For DOT-regulated employees, continue federal testing procedures unchanged. For employees in the building and construction trades or federal-clearance roles, traditional urine testing for marijuana remains an option, though many California employers in these sectors are still moving toward oral fluid testing for consistency across the workforce.

Update written policies to reflect the new method, train supervisors on reasonable-suspicion documentation, and remove any cannabis-specific questions from job applications and interview scripts to comply with SB 700.

When AB 2188 most affects an employer's program

The California rules around marijuana testing matter most when an employer:

• Hires applicants in California for non-construction, non-federal-clearance roles
• Runs a non-DOT random or post-accident testing program
• Uses urine testing as the only method for the THC analyte
• Asks any cannabis-related question on a job application or in interviews
• Operates across multiple states with one standardized policy that does not account for California's stricter rules

If any of these describe your program, AB 2188 and SB 700 require a workflow update — and the most common practical fix is moving the THC component of the panel to oral fluid testing.

Final takeaway

For California employers, the rules around workplace marijuana testing changed permanently on January 1, 2024. AB 2188 prohibits adverse employment action based on tests that detect non-psychoactive cannabis metabolites — which rules out urine testing as the sole basis for marijuana-related discipline in most workplaces. SB 700 prohibits asking applicants about prior cannabis use. The narrow exemptions for the building and construction trades, federal-clearance roles, and DOT-regulated positions remain. For non-exempt California employers, the most practical compliant approach is oral fluid testing for the THC component of the panel, with urine testing for other analytes. The right final program should still align with company policy, role-by-role classification, and the specific industry's exposure to AB 2188.

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Sources

• California Legislative Information, Assembly Bill 2188 — Discrimination in employment: use of cannabis (signed September 18, 2022; effective January 1, 2024)
• California Legislative Information, Senate Bill 700 — Employment discrimination: cannabis use (signed October 7, 2023; effective January 1, 2024)
• California Government Code Section 12954
• California Health and Safety Code Section 11362.45
• SAMHSA, Mandatory Guidelines for Federal Workplace Drug Testing Programs — Urine and Oral Fluid (current edition)
• U.S. Department of Transportation, 49 CFR Part 40 — Procedures for Transportation Workplace Drug and Alcohol Testing Programs
• Jackson Lewis, "Building an Exemption: California Construction Employers Allowed to Drug Test for Marijuana" (August 2025)
• CDF Labor Law LLP, "New Rules For California Employers Testing for Marijuana Use Are Approaching Fast"
• California Chamber of Commerce, "How State Cannabis Laws Affect Testing, Questions About Use" (February 2024)
• PRISM, "California Limits Cannabis Drug Testing (AB 2188 and SB 700)"

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Disclosure: My BIO TESTS® sells rapid urine and oral fluid drug screening tests in three regulatory categories: CLIA-Waived FDA 510(k)–cleared, Employer & Insurance Use Only, and Forensic Use Only. Selection of the appropriate category depends on your testing program and use case. Positive results from any rapid screening test are presumptive and should be confirmed by an HHS-certified laboratory and reviewed by a qualified Medical Review Officer (MRO). This content is educational and reflects state and federal law as of the date of publication; marijuana employment law changes frequently, and California specifically continues to evolve through legislation, agency guidance, and case law. This is not legal advice. Consult a qualified California employment attorney before making policy or testing decisions for your workforce.

Last updated: May 2026