Are Workplace Drug Tests Legal in California? Rules and Refusals

Workplace drug testing laws in California are tighter than in most states because the state constitution treats privacy as an inalienable right. Employers can require a drug test from job applicants after extending a conditional offer, and they can test current employees when they have a specific, documented reason like suspected on-the-job impairment or a serious workplace accident. Blanket or random testing of current workers is off-limits outside narrow safety-sensitive roles. And since January 1, 2024, employers generally cannot punish workers for cannabis use that happens off the clock.

When an Employer Can Test a Job Applicant

An employer can condition a job on passing a drug test, but only after a conditional offer has been made. The California Supreme Court set this framework in Loder v. City of Glendale, holding that pre-employment drug screening is permissible when it is part of a post-offer medical examination required of everyone entering the same job category.¹

The testing requirement has to apply uniformly to every applicant for that type of position. Singling out one applicant based on race, gender, disability, or another protected characteristic is unlawful. If the applicant tests positive, the employer can rescind the offer, subject to the cannabis rules discussed below.

Refusing to take the test as an applicant is straightforward: the employer can withdraw the offer.

When an Employer Can Test a Current Employee

Once you are on the payroll, your privacy interest goes up, and the employer needs a real reason to demand a test. California courts have consistently struck down suspicionless testing programs for most current employees as an invasion of the privacy right in Article I, Section 1 of the state constitution.²

Reasonable Suspicion of Impairment

The most common lawful basis is reasonable suspicion that the employee is impaired at work. The suspicion has to rest on observable, objective facts a supervisor can document: slurred speech, the smell of alcohol, coordination problems, erratic behavior, or similar signs. A vague hunch or personal dislike is not enough. Courts have upheld testing grounded in specific facts and rational inferences even when the evidence falls short of criminal probable cause.³

After a Serious Workplace Accident

Employers can require testing after a serious workplace accident to investigate whether impairment was a factor, and California courts have upheld the practice.³ OSHA has clarified that post-incident testing is permissible when used to evaluate the root cause of an incident that harmed or could have harmed workers, but the employer should test everyone whose conduct could have contributed, not just the person who reported an injury.⁴

Random Testing Is Mostly Prohibited

Random testing of current employees is generally not allowed in California. The exception is narrow: courts have upheld random testing for people in genuinely safety-sensitive jobs, such as bus drivers and certain law enforcement roles, where the public safety interest outweighs individual privacy. For office staff, retail workers, and most other positions, an employer cannot pull names out of a hat and demand a urine sample.³

What Happens If You Refuse

The California Employment Development Department treats refusal differently depending on whether the request was legally reasonable.⁵

If the employer had a valid basis, such as reasonable suspicion, a post-accident inquiry, or a federal regulatory requirement, refusing counts as insubordination. You can be fired for it, and if you apply for unemployment benefits, the refusal will likely be treated as misconduct connected with your work.⁵

If the request was unreasonable, say, a random test for a non-hazardous desk job with no documented suspicion, then refusing is not insubordination. A firing on those facts may not count as misconduct for unemployment purposes, and the employee may have a wrongful termination claim.

Cannabis Rules Since 2024

Government Code Section 12954, effective January 1, 2024, makes it unlawful for an employer to discriminate against someone in hiring, firing, or any other employment decision based on their use of cannabis off the job and away from the workplace.⁶

The law targets a specific testing problem. Standard urine and hair tests pick up non-psychoactive cannabis metabolites, which are chemical traces that linger for days or weeks after use and say nothing about current impairment. Under Section 12954, an employer cannot use a test result showing those metabolites to make an employment decision. If an employer wants to screen for cannabis, it has to use a method that does not screen for non-psychoactive metabolites.⁶

Employers also cannot ask job applicants about prior cannabis use, whether on the application, in an interview, or through any other pre-hire inquiry.⁶

The law does not give anyone the right to be impaired at work or to possess cannabis on the job. An employer can maintain a drug-free workplace and act against a worker who shows up high.

Who Is Not Covered

The cannabis protections carve out three groups:

Workers in the building and construction trades are entirely excluded.⁶
Applicants and employees in positions requiring a federal background investigation or security clearance under Department of Defense regulations or equivalent rules from other agencies are exempt.⁶
The law does not preempt any state or federal rule requiring testing as a condition of employment, federal funding, federal licensing, or a federal contract.⁶

If you work in construction or hold a position tied to a federal security clearance, your employer can still use a traditional metabolite-based test and rely on the results.

Medical Marijuana Cards

A California medical marijuana card does not require your employer to accommodate your use. Cannabis remains a Schedule I controlled substance under federal law, and the Americans with Disabilities Act does not protect the use of federally illegal substances. Federal courts have consistently held that employers face no obligation to accommodate medical marijuana use even when the employee holds a valid state recommendation. Section 12954 protects off-duty use from being held against you, but it does not create a right to use cannabis at work or force employers to ignore on-the-job impairment.

Federally Regulated Jobs Are Different

Federal law overrides California’s privacy-based restrictions for workers in certain safety-sensitive roles. The clearest example is the Department of Transportation, which requires random drug and alcohol testing for employees performing safety-sensitive functions across several industries.⁷

DOT testing follows the procedures in 49 CFR Part 40 and screens for five drug categories: marijuana metabolites, cocaine, amphetamines, opiates, and PCP.⁸ DOT tests still screen for marijuana metabolites even though California has legalized recreational use; the federal rules do not bend to state cannabis laws.

Covered workers include truck drivers regulated by the Federal Motor Carrier Safety Administration, airline employees under the Federal Aviation Administration, railroad workers under the Federal Railroad Administration, and transit workers under the Federal Transit Administration.⁷ If you hold one of these positions, your employer can and must conduct random tests regardless of California law.

Prescription Medications

A positive test caused by a legally prescribed medication raises separate legal issues. Under the ADA, disability-related inquiries and medical examinations of current employees are only permitted when they are job-related and consistent with business necessity.⁹

In practice, that means an employer generally cannot demand you disclose every medication you take just because a test is being administered. If a test picks up a lawfully prescribed substance, a medical review officer typically contacts the employee to verify the prescription before any result reaches the employer. Firing someone solely because they tested positive for a medication they are lawfully prescribed to treat a disability could amount to disability discrimination.

Rehabilitation and Leave Rights

California Labor Code Section 1025 requires private employers with 25 or more employees to reasonably accommodate any worker who voluntarily enters an alcohol or drug rehabilitation program, as long as the accommodation does not impose an undue hardship.¹⁰

The protection has real limits. An employer can still fire an employee whose current drug or alcohol use makes them unable to do the job or creates a safety risk.¹⁰ The law does not require paid time off for rehab, though accrued sick leave can be used. The employer also has to make reasonable efforts to keep the enrollment confidential.

At the federal level, the Family and Medical Leave Act can provide up to 12 weeks of job-protected unpaid leave for substance abuse treatment, but only when the treatment qualifies as a serious health condition involving inpatient care or continuing treatment by a healthcare provider. Absences caused by substance use itself, rather than by treatment, do not qualify. An employer with an established, consistently enforced substance abuse policy can still terminate an employee under that policy even while the employee is on FMLA leave for treatment.¹¹

The ADA can also protect someone who has completed rehabilitation and is no longer using illegal drugs from discrimination based on their history of addiction, provided the addiction substantially limited a major life activity. Casual past use without addiction does not qualify.

1
Justia Law. Loder v. City of Glendale (1997)
2
California Legislative Information. California Constitution Article I, Section 1
3
CalChamber. California Drug and Alcohol Testing Laws
4
Occupational Safety and Health Administration. Clarification of OSHA’s Position on Workplace Safety Incentive Programs and Post-Incident Drug Testing Under 29 CFR 1904.35(b)(1)(iv)
5
Employment Development Department. Misconduct MC 270
6
California Legislative Information. California Government Code 12954
7
Federal Motor Carrier Safety Administration. Best Practices for DOT Random Drug and Alcohol Testing
8
eCFR. 49 CFR Part 40 – Procedures for Transportation Workplace Drug and Alcohol Testing Programs
9
U.S. Equal Employment Opportunity Commission. Enforcement Guidance on Disability-Related Inquiries and Medical Examinations of Employees under the ADA
10
California Legislative Information. California Labor Code 1025
11
U.S. Department of Labor. Family and Medical Leave Act Advisor – Serious Health Condition – Leave for Treatment of Substance Abuse