Employer Guide to Workplace Drug Testing

Workplace drug testing is regulated by a patchwork of federal, state, and local laws. While federal law does not generally require private employers to drug test (except in certain regulated industries), employers who choose to test must navigate complex legal requirements. The legalization of marijuana in many states has added another layer of complexity.

Types of Drug Testing

Employers may conduct drug testing in several situations:

• Pre-employment testing: After a conditional offer of employment, before the employee starts work
• Reasonable suspicion testing: When a supervisor has objective, articulable reasons to believe an employee is under the influence
• Post-accident testing: After a workplace accident, often limited to situations where impairment may have been a contributing factor
• Random testing: Unannounced testing of employees selected through a random process
• Return-to-duty and follow-up testing: After an employee returns from a substance abuse treatment program

Not all types of testing are permitted in all states. Some states restrict random testing to safety-sensitive positions or require specific conditions before testing is allowed.

Federal Requirements for Regulated Industries

Certain industries are subject to mandatory drug and alcohol testing under federal regulations:

• DOT-regulated employers: Including trucking, aviation, rail, transit, pipeline, and maritime industries must follow DOT testing procedures under 49 CFR Part 40
• Federal contractors: The Drug-Free Workplace Act requires federal contractors to maintain a drug-free workplace but does not mandate testing
• Nuclear Regulatory Commission licensees: Subject to mandatory testing under NRC regulations

DOT testing follows strict protocols including a specific five-panel drug test, use of certified laboratories, Medical Review Officer (MRO) review, and detailed recordkeeping requirements.

State Law Considerations

State laws create a complex landscape for drug testing:

• Some states require employers to have a written drug testing policy before conducting any tests
• Several states limit testing to specific circumstances (such as reasonable suspicion or post-accident)
• An increasing number of states and cities prohibit adverse action based on positive marijuana tests for off-duty use
• Some states require confirmation testing using a second method (such as GC-MS) before taking adverse action
• Many states require that testing be performed by a certified laboratory
• Several states require employee assistance program (EAP) referrals before or instead of termination for a positive test

Developing a Drug Testing Policy

An effective drug testing policy should address:

• The purpose and scope of the program
• Which positions are subject to testing and what types of testing apply
• What substances are tested and what constitutes a positive result
• The consequences of a positive test, refusal to test, or adulteration of a sample
• Confidentiality protections for test results
• The employee's right to explain a positive result (prescription medications)
• EAP referral information
• Applicable state law requirements

Marijuana in the Workplace

Marijuana legalization creates unique challenges for employers:

• Federal law still classifies marijuana as a Schedule I controlled substance
• DOT-regulated employers must continue to treat marijuana as a prohibited substance regardless of state law
• Non-regulated employers should review state and local laws before taking adverse action based on marijuana test results
• Many states protect employees from adverse action for lawful off-duty marijuana use
• No state requires employers to permit marijuana use or impairment in the workplace
• Consider whether your drug testing program should focus on impairment rather than presence of metabolites