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

**Citation:** 49 CFR 40.181  
**Type / status:** regulation / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2026-08-18  
**Published:** Not stated

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.

[88 FR 27646, May 2, 2023]

## Document text

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.

[88 FR 27646, May 2, 2023]

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-49/section-40.181>
- Source ID: `ecfr`
- SHA-256: `c6360a91ad2c167ef2698803e8dc241002f6e5f6f11d4595eb85bf7c6c625dff`
- Retrieved: 2026-08-20T05:54:21.729Z
- Exported: 2026-08-22T23:43:53.927Z
- Document slug: `49-cfr-40-181`

### Source metadata

```json
{
  "cfrTitle": 49,
  "part": "40",
  "section": "40.181",
  "subpart": "Subpart H—Split Specimen Tests",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```