DOT Rule 49 CFR Part 40 Section 40.91
Subpart F - Drug Testing Laboratories
§ 40.91 What are the cutoff concentrations for oral fluid drug tests?
As a laboratory, you must use the cutoff concentrations displayed in the following table for initial and confirmatory drug tests for oral fluid specimens. All cutoff concentrations are expressed in nanograms per milliliter (ng/mL). The table follows:
Initial test analyte |
Initial test cutoff1 |
Confirmatory test analyte |
Confirmatory test cutoff concentration |
Marijuana (THC)2 |
4 ng/mL3 |
THC |
2 ng/mL. |
Cocaine/Benzoylecgonine |
15 ng/mL |
Cocaine Benzoylecgonine |
8 ng/mL. 8 ng/mL |
Codeine/Morphine |
30 ng/mL |
Codeine |
15 ng/mL. |
Hydrocodone/Hydromorphone |
30 ng/mL |
Hydrocodone |
15 ng/mL. |
Oxycodone/Oxymorphone |
30 ng/mL |
Oxycodone |
15 ng/mL. |
6-Acetylmorphine |
4 ng/mL 3 |
6-Acetylmorphine |
2 ng/mL. |
Phencyclidine |
10 ng/mL |
Phencyclidine |
10 ng/mL. |
Amphetamine/Methamphetamine |
50 ng/mL |
Amphetamine |
25 ng/mL. |
MDMA4/MDA5 |
50 ng/mL |
MDMA |
25 ng/mL. |
1For grouped analytes (i.e., two or more analytes that are in the same drug class and have the same initial test cutoff):
Immunoassay: The test must be calibrated with one analyte from the group identified as the target analyte. The cross-reactivity of the immunoassay to the other analyte(s) within the group must be 80 percent or greater; if not, separate immunoassays must be used for the analytes within the group.
Alternate technology: Either one analyte or all analytes from the group must be used for calibration, depending on the technology. At least one analyte within the group must have a concentration equal to or greater than the initial test cutoff or, alternatively, the sum of the analytes present (i.e., equal to or greater than the laboratory’s validated limit of quantification) must be equal to or greater than the initial test cutoff.
2An immunoassay must be calibrated with the target analyte.
3Alternate technology (THC and 6-AM): The confirmatory test cutoff must bused for an alternate technology initial test that is specific for the target analyte (i.e., 2ng/mL for THC, 2ng/mL for 6-AM).
4Methylenedioxymethamphetamine (MDMA).
5Methylenedioxyamphetamine (MDA).
[88 FR 27643, May 2, 2023]