§40.155 What does the MRO do when a negative or positive test result is also dilute?

Current as of Oct 29, 2026Last amended Oct 17, 2016Official text on eCFR ↗

(a) When the laboratory reports that a specimen is dilute, you must, as the MRO, report to the DER that the specimen, in addition to being negative or positive, is dilute.

(b) You must check the “dilute” box (Step 6) on Copy 2 of the CCF.

(c) When you report a dilute specimen to the DER, you must explain to the DER the employer's obligations and choices under § 40.197, to include the requirement for an immediate recollection under direct observation if the creatinine concentration of a negative-dilute specimen was greater than or equal to 2mg/dL but less than or equal to 5mg/dL.

(d) If the employee's recollection under direct observation, in paragraph (c) of this section, results in another negative-dilute, as the MRO, you must:

(1) Review the CCF to ensure that there is documentation that the recollection was directly observed.

(2) If the CCF documentation shows that the recollection was directly observed as required, report this result to the DER as a negative-dilute result.

(3) If CCF documentation indicates that the recollection was not directly observed as required, do not report a result but again explain to the DER that there must be an immediate recollection under direct observation.

Source: 65 FR 79526, Dec. 19, 2000, as amended at 66 FR 41952, Aug. 9, 2001; 68 FR 31626, May 28, 2003; 69 FR 64867, Nov. 9, 2004; 73 FR 35971, June 25, 2008

Compiled from the Electronic Code of Federal Regulations (eCFR), an editorial compilation and not an official legal edition of the CFR. The official text is the Federal Register and the annual CFR edition. §40.155 on eCFR.

Sections that cite this one

  • §40.197 What happens when an employer receives a report of a dilute urine specimen?
  • Appendix H to Part 40 Appendix H to Part 40—Drug and Alcohol Testing Information that C/TPAs May Transmit to Employers