§FMCSR.com
Historical textIn force on Sept. 30, 2004Source: annual CFR editions 2003–2004

§ 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Wording in the annual edition revised as of Oct. 1, 2003, superseded by the 2005 annual edition.

govinfo, 2003 edition ↗
Before Jan. 1, 2017 the record is one snapshot per annual CFR edition, revised as of October 1. This is the 2003 edition's wording. An amendment that took effect between Oct. 1, 2003 and Sept. 30, 2004 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, 2004. This wording effective October 1, 2003 to October 1, 2005. Source: govinfo, 2003 edition, https://www.govinfo.gov/app/details/CFR-2003-title49-vol1/CFR-2003-title49-vol1-sec40-155. Retrieved from FMCSR.com, https://fmcsr.com/reg/40.155?asof=2004-09-30, on October 26, 2026. Unofficial compilation; verify against the official source.

(a) When the laboratory reports that a specimen is dilute, or reports that a specimen is substituted with a creatinine quantitation of greater than or equal to 2 mg/dL, 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.

[65 FR 79526, Dec. 19, 2000, as amended at 66 FR 41952, Aug. 9, 2001; 68 FR 31626, May 28, 2003]

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. 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]
  3. Oct. 1, 2003 → Oct. 1, 2005annual editions 2003–2004diff vs. previousviewing
    [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.