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Specimen validity testing is the evaluation of a specimen (provided for controlled substance testing) to determine if it is consistent with normal human urine or oral fluid.
The purpose of validity testing is to determine whether:
- Certain adulterants or foreign substances were added to the specimen,
- The specimen was diluted, or
- The specimen was substituted.
Scope
These requirements apply to drug testing laboratories.
Regulatory citations
- 49 CFR 40, Subpart F — Drug testing laboratories
Key definitions
- Adulterated specimen: In drug testing, a specimen that has been altered, as evidenced by test results showing either a substance that is not a normal constituent for that type of specimen or showing an abnormal concentration of an endogenous substance.
- Dilute specimen: A urine specimen with creatinine and specific gravity values that are lower than expected for human urine.
- Invalid drug test: The result reported by a U.S. Department of Health and Human Services (HHS) certified laboratory in accordance with the criteria established by HHS Mandatory Guidelines when a positive, negative, adulterated, or substituted result cannot be established for a specific drug or specimen validity test.
- Invalid result: The result reported by an HHS-certified in accordance with the criteria established by HHS when a positive, negative, adulterated, or substituted result cannot be established for a specific drug or specimen validity test.
- Substituted specimen: An employee’s specimen not consistent with a normal human specimen, as determined by HHS (e.g., a urine specimen, with creatinine and specific gravity values that are so diminished, or so divergent that they are not consistent with normal human urine).
- Validity testing: The evaluation of a specimen (provided for controlled substance testing) to determine if it is consistent with normal human urine or oral fluid.
Summary of requirements
Laboratories must conduct validity testing. A laboratory that conducts validity testing must follow certain, specific procedures.
Urine-specimen validity testing
Specimen validity testing is the evaluation of the specimen to determine if it is consistent with normal human urine. The purpose of validity testing is to determine whether certain adulterants or foreign substances were added to the urine, if the urine was diluted, or if the specimen was substituted.
Laboratories conduct validity testing in accordance with the requirements in 40.87. They must determine the primary specimen’s:
- Creatinine concentration,
- Specific gravity, if they find the creatinine concentration to be less than 20 mg/dL, and
- pH.
Oral-fluid specimen validity testing
Oral-fluid specimen validity testing is the evaluation of the specimen to determine if it is consistent with normal human oral fluid. The purpose of validity testing is to determine whether certain adulterants or foreign substances were added to the oral fluid, if the oral fluid was altered.
If a specimen exhibits abnormal characteristics (e.g., unusual odor or color), causes reactions or responses characteristic of an adulterant during initial or confirmatory drug tests, or contains an unidentified substance that interferes with the confirmatory analysis, then the laboratory may conduct validity testing.
If the laboratory determines that the specimen is invalid and HHS guidelines direct them to contact the MRO, they must contact the MRO and together decide if testing the primary specimen by another HHS-certified laboratory would be useful in being able to report a positive or adulterated test result.
A laboratory must conduct validity testing in accordance with the requirements in 40.93.
- They may test for a biomarker such as albumin or immunoglobulin G (IgG) or a test for a specific adulterant.
- They must follow the applicable HHS requirements for any additional validity testing.