Are Workplace Drug Tests Legal in California?

Workplace drug tests are legal in California, but the rules are tighter than in most states because the California Constitution treats privacy as an inalienable right. Employers can require a drug test from a job applicant after making a conditional offer, and they can test a current employee when they have a specific, documented reason. Blanket or random testing of current employees is off-limits for most jobs, and since January 1, 2024, state law also restricts how employers can use cannabis test results.

When Employers Can Test Job Applicants

A California employer can require a drug test as part of hiring, but only after extending a conditional offer of employment. That means interviews, background checks, and other screening have to come first. The testing requirement also has to apply uniformly to everyone offered the same type of position. Singling an applicant out based on race, gender, disability, or another protected characteristic is unlawful.¹

If an applicant tests positive, the employer can legally rescind the offer, subject to the cannabis rules discussed below.

When Employers Can Test Current Employees

Once you are on the payroll, your expectation of privacy goes up and the employer needs a justifiable reason to demand a test. California courts have repeatedly struck down suspicionless testing of current employees as an unconstitutional 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, poor coordination, erratic behavior, or similar indicators. A vague feeling or personal dislike is not enough. Courts have supported testing grounded in specific facts and rational inferences from them, even where the evidence falls short of criminal probable cause.³

After a Serious Workplace Accident

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

Random Testing Is Generally Prohibited

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

Cannabis Rules Since January 1, 2024

California Government Code Section 12954 now 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.⁵

The law targets a specific testing problem. Traditional urine and hair tests detect non-psychoactive cannabis metabolites, which linger in the body for days or weeks and say nothing about current impairment. Under Section 12954, an employer cannot base an employment decision on a test showing those metabolites. If an employer wants to screen for cannabis, it has to use a method that does not look for non-psychoactive metabolites. Employers also cannot ask job applicants about prior cannabis use on applications, in interviews, or through any other pre-hire inquiry.⁵

None of this gives employees a right to be impaired at work or to possess cannabis on the job. An employer can still keep a drug-free workplace and act against someone who shows up high.

Who Is Not Covered

The cannabis protections carve out several groups:

Workers in the building and construction trades are entirely excluded.⁵
Applicants and employees in positions requiring a federal background investigation or security clearance under Department of Defense regulations or equivalent federal rules are exempt.⁵
The law does not preempt any state or federal rule requiring controlled-substance testing as a condition of employment, federal funding, federal licensing, or a federal contract.⁵

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 act on the results.

A Medical Marijuana Card Does Not Change This

Holding a California medical marijuana card does not require your employer to accommodate your use. Cannabis is still 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 employers have no duty to accommodate medical marijuana, even with a valid state recommendation. Section 12954 protects off-duty use from being held against you; it does not create a right to use at work or to be impaired on the job.

Federally Regulated Jobs Override State Limits

Federal law overrides California’s privacy-based restrictions for certain safety-sensitive workers. The Department of Transportation requires random drug and alcohol testing for employees performing safety-sensitive functions, including truck drivers, airline employees, railroad workers, and transit workers.⁶

DOT testing follows strict procedures under 49 CFR Part 40 and screens for five drug categories: marijuana metabolites, cocaine, amphetamines, opiates, and PCP.⁷ DOT tests still screen for marijuana metabolites even though California has legalized recreational use. Federal rules do not bend to state cannabis laws. If you hold one of these positions, your employer can and must conduct random drug tests regardless of what California law otherwise says.

What Happens If You Refuse a Drug Test

The consequences of refusing depend on whether the request was legally reasonable. The Employment Development Department sets this out in its unemployment insurance guidance.⁸

If the request was reasonable, meaning the employer had grounds like reasonable suspicion of impairment, a post-accident investigation, or a federal regulatory requirement, refusing counts as insubordination. The employer can fire you, and if you apply for unemployment, the refusal will likely be treated as misconduct connected with your work.⁸

If the request was unreasonable, such as a random test for a non-hazardous desk job with no documented suspicion, refusing is not insubordination. A resulting termination may not be treated as misconduct for unemployment purposes, and the employee may have grounds for a wrongful termination claim.

For applicants, the math is simpler. An employer can condition the offer on passing a drug test, and refusing gives the employer a clean reason to withdraw the offer.

Prescription Medications

A positive result for a lawfully prescribed medication raises different issues. Under the ADA, during employment, disability-related inquiries and medical examinations are only permitted when they are job-related and consistent with business necessity.⁹

Practically, your employer generally cannot demand a full list of your medications just because a test is being administered. If a test picks up a prescribed substance, a medical review officer typically contacts the employee to verify the prescription before reporting a result to the employer. Firing someone solely for testing positive for a medication they are lawfully prescribed to treat a disability can amount to disability discrimination.

Rights If You Seek Rehabilitation

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

The limits matter. 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. The law does not require paid time off for rehab, though employees can use accrued sick leave. The employer must make reasonable efforts to keep enrollment confidential.¹⁰

Federally, 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 treatment, are not FMLA-protected. An employer with an established, consistently enforced policy against substance abuse can still terminate an employee under that policy, even if the employee is on FMLA leave for treatment.¹¹

The ADA adds a further layer. A person who has completed rehabilitation and is no longer using illegal drugs may be protected from discrimination based on their history of addiction, if the addiction substantially limited a major life activity. Casual past use without addiction does not qualify as a disability.

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
California Legislative Information. California Government Code 12954
6
Federal Motor Carrier Safety Administration. Best Practices for DOT Random Drug and Alcohol Testing
7
eCFR. 49 CFR Part 40 – Procedures for Transportation Workplace Drug and Alcohol Testing Programs
8
Employment Development Department. Misconduct MC 270
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