There are five safeguards to protect workers and employers:
Rules for specimen collection.
Only SAMHSA (Substance Abuse Mental Health Services Administration) specially certified laboratories are used for DOT regulated drug testing.
Medical Review Officers review the laboratory drug testing results to determine if there is an alternative medical reason for a positive test.
DOT (Department of Transportation) regulations and procedures.
DHHS (Department of Health and Human Services) mandatory guidelines for federal drug free workplace testing programs