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HelpTest Code CRUO Chromium Occupational Exposure, Random, Urine
Ordering Guidance
High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Specimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube: Clean, plastic urine collection container
Submission Container/Tube: Plastic, 5-mL tube or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 3 mL
Collection Instructions:
1. Collect a random urine specimen.
2. See Metals Analysis Specimen Collection and Transport for complete instructions.
Useful For
Screening for occupational exposure
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CROM1 | Chromium Occupational Exposure, U | No | Yes |
| CRETR | Creatinine, Random, U | No | Yes |
Special Instructions
Method Name
CROM1: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
CRETR: Enzymatic Colorimetric Assay
Reporting Name
Chromium Occupat Exp, Random, USpecimen Type
UrineSpecimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 14 days |
Reference Values
0-17 years: Not established
≥18 years: The American Conference of Governmental Industrial Hygienists (ACGIH) Biological Exposure Index (BEI) for daily occupational exposure to hexavalent chromium in urine is an increase of 10.0 mcg/L between pre-shift and post-shift urine collections. The ACGIH BEI for long- and short-term hexavalent chromium in urine is an end-of-shift concentration above 24.9 mcg/L at the end of the work week.
Interpretation
The National Institute for Occupational Safety and Health draft document on occupational exposure reviews the data supporting use of urine to assess chromium exposure.(1) They recommend a Biological Exposure Index of 10 mcg/g creatinine and 30 mcg/g creatinine for the increase in urinary chromium concentrations during a work shift and at the end of shift at the end of the workweek, respectively (Section 3.3.1).
Clinical Reference
1. Centers for Disease Control and Prevention; National Institute for Occupational Safety and Health (NIOSH). Criteria for a recommended standard occupational exposure to hexavalent chromium. CDC; September 2013. Accessed November 06, 2020. Available at www.cdc.gov/niosh/docs/2013-128/pdfs/2013_128.pdf
2. Sodi R. Vitamins and trace elements. In: Rifai N, Chiu RWK, Young I, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 39
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82495
82570
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CRUO | Chromium Occupat Exp, Random, U | 13464-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CRETR | Creatinine, Random, U | 2161-8 |
| 607761 | Chromium Occupational Exposure | 13464-3 |
| 608390 | Chromium Concentration | 5623-4 |
Day(s) Performed
Tuesday, Wednesday, Friday