Your Rights After a Cannabis Drug Test

A positive cannabis drug test is not the end of the story. You have specific rights under federal law (49 CFR Part 40), state employment law, and contract or collective bargaining agreements. The most important thing is to act fast: many of these rights have strict time deadlines, often measured in hours or days.

The 72-Hour Rule

Under federal DOT testing rules, you have 72 hours from MRO notification to request a split specimen retest. After that window closes, you cannot challenge the original lab result this way. Time matters.

Hands receiving a plain sealed white envelope across a wooden desk

What You Need to Know

  • The full federal testing process under 49 CFR Part 40
  • How to interact with the Medical Review Officer (MRO)
  • Your right to request a split specimen retest
  • How to challenge chain-of-custody issues
  • Your rights under state employment protections
  • How union representation affects your rights

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Critical Time Deadlines

ActionDeadline
Provide medical documentation to MRO5 business days
Request split specimen testing (DOT)72 hours from MRO notification
File EEOC complaint (if applicable)180 or 300 days
State employment claim filing deadlinesVaries by state, often 60–180 days
Union grievance filingVaries by CBA, often 5–30 days

Get an attorney as soon as you know there is a problem. Time is the most precious resource you have in challenging a positive test result.