§FMCSR.com
Historical textIn force on Sept. 30, 2006Source: annual CFR editions 2005–2007

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

Wording in the annual edition revised as of Oct. 1, 2005, superseded by the 2008 annual edition.

govinfo, 2005 edition ↗
Before Jan. 1, 2017 the record is one snapshot per annual CFR edition, revised as of October 1. This is the 2005 edition's wording. An amendment that took effect between Oct. 1, 2005 and Sept. 30, 2006 would not appear until the next edition, so check the citations below and the Federal Register for exact effective dates.
49 CFR § 40.155 — What does the MRO do when a negative or positive test result is also dilute?. Text in force on September 30, 2006. This wording effective October 1, 2005 to October 1, 2008. Source: govinfo, 2005 edition, https://www.govinfo.gov/app/details/CFR-2005-title49-vol1/CFR-2005-title49-vol1-sec40-155. Retrieved from FMCSR.com, https://fmcsr.com/reg/40.155?asof=2006-09-30, on October 26, 2026. Unofficial compilation; verify against the official source.

(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.

[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]

Amendment history

4 distinct wordings on file since Oct. 1, 2001
  1. Oct. 1, 2008 → presentannual editions 2008–2016diff vs. previous
    [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]
  2. Oct. 1, 2005 → Oct. 1, 2008annual editions 2005–2007diff vs. previousviewing
    [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]
  3. Oct. 1, 2003 → Oct. 1, 2005annual editions 2003–2004diff vs. previous
    [65 FR 79526, Dec. 19, 2000, as amended at 66 FR 41952, Aug. 9, 2001; 68 FR 31626, May 28, 2003]
  4. Oct. 1, 2001 → Oct. 1, 2003annual editions 2001–2002
    [65 FR 79526, Dec. 19, 2000, as amended at 66 FR 41952, Aug. 9, 2001]

A new entry appears whenever the regulatory words change between government snapshots. Day-precise from the eCFR (2017 onward); before that, one snapshot per annual CFR edition (revised as of October 1). Bracketed citations are the Federal Register history printed with the section.