Hippuric Acid, Urine

Casandra

Casandra Test Code MC92083Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID HIPACPT Codes 81002, 82570, 83921

Clinical Use

Use

Analysis of urinary hippuric acid provides a marker for exposure to toluene and related aromatic solvents, as hippuric acid (also called benzoylglycine, hippurate, n‑benzoylglycine, or toluene metabolite) is the principal urinary metabolite. Interpretation includes reporting of hippuric acid concentration (g/L), creatinine‑corrected value (g/g creatinine), and a specific gravity check to ensure specimen validity. Reference values indicate that in unexposed populations, urinary hippuric acid levels are generally less than 1.6 g/L and creatinine‑corrected values less than 1.5 g/g, with physiologic specific gravity between 1.010–1.030. Results include reporting limits to detect analytical thresholds.

Special Instructions

Specimen collection requires 3 mL of random urine collected at end of shift in a plastic preservative‑free urine container, to be sent refrigerated. Stability includes refrigerated or frozen storage up to 30 days, or ambient up to 5 days. Not cleared or approved by the U.S. Food and Drug Administration; developed by NMS Labs. NY State approval is indicated. The test is performed daily (Monday through Sunday).

Limitations

Reporting limit is determined with each analysis, and results may be affected by specimen stability or improper storage. The test classification indicates the assay was developed and performance characteristics determined by NMS Labs and has not been FDA‑cleared or approved, which may affect interpretation of regulatory standing. Specific gravity confirmation ensures the adequacy of the specimen for accurate measurement; deviations may necessitate recollection.

Test Details

New York Approved