§ 40.93 What criteria do laboratories use to establish that a specimen is dilute or substituted?
Wording in the annual edition revised as of Oct. 1, 2005, superseded May 2, 2023.
(a) As a laboratory, you must consider the primary specimen to be dilute when:
(1) The creatinine concentration is greater than or equal to 2 mg/dL but less than 20 mg/dL, and
(2) The specific gravity is greater than 1.0010 but less than 1.0030 on a single aliquot.
(b) As a laboratory, you must consider the primary specimen to be substituted when the creatinine concentration is less than 2 mg/dL and the specific gravity is less than or equal to 1.0010 or greater than or equal to 1.0200 on both the initial and confirmatory creatinine tests and on both the initial and confirmatory specific gravity tests on two separate aliquots.
[69 FR 64867, Nov. 9, 2004]
Amendment history
5 distinct wordings on file since Oct. 1, 1996- [88 FR 27643, May 2, 2023]
- [69 FR 64867, Nov. 9, 2004]
- [69 FR 64867, Nov. 9, 2004]
- Oct. 1, 1996 → Oct. 1, 2001annual editions 1996–2000
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.