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DOT Rule 49 CFR Part 40 Section 40.181

Subpart H - Split Specimen Tests

§ 40.181 What does the second laboratory do with the split specimen when it is tested to reconfirm a substituted test result?

As the laboratory testing a urine split specimen, you must test the split specimen using the confirmatory tests for creatinine and specific gravity, and using criteria set forth in § 40.88.
[65 FR 79526, Dec. 19, 2000, as amended 73 FR 35973, June 25, 2008; 88 FR 27646, May 2, 2023]