---
kind: "section"
citation: "49 C.F.R. § 40.181"
title: "49"
number: "40.181"
heading: "What does the second laboratory do with the split specimen when it is tested to reconfirm a substituted test result?"
url: "https://uscodex.org/cfr/49/40.181"
---

# §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, using the criteria set forth in [§ 40.88](/cfr/49/40.88.md).


## Notes

### Amendments

[88 FR 27646, May 2, 2023]

### Authority

Authority: 49 U.S.C. 102, 301, 322, 5331, 20140, 31306, and 54101 et seq.

### Source

Source: 65 FR 79526, Dec. 19, 2000, unless otherwise noted.

### Amendments

[88 FR 27646, May 2, 2023]