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Cobalt/Creatinine Ratio, 24-Hour Urine

Published: August 9, 2026Updated: August 17, 2026

Measures cobalt relative to creatinine in a 24-hour urine collection, helping assess urinary cobalt while accounting for urine concentration.

Quick summary

["This test can help evaluate potential occupational cobalt exposure using a 24-hour urine sample."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
52933-9
Short code
Cobalt/Creat 24h Ur-sRto
Synonyms
Cobalt/Creat 24h Ur-sRto
Category
liver
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
7
Ref high
56
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84484
SNOMED
302773008
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures the amount of cobalt in urine compared with the amount of creatinine. Creatinine is used as an adjustment factor because it changes with urine concentration.

Why might I need this test?

It may be used to monitor people who work with cobalt or cobalt-containing materials, such as in metal processing, battery manufacturing, or certain industrial settings.

How is the test performed?

You collect all urine for a full 24-hour period in the container provided by the laboratory or workplace. The laboratory then measures cobalt and creatinine and calculates their ratio.

How do I prepare for the test?

Follow the collection instructions exactly and record the collection start and end times. Tell the laboratory about workplace cobalt exposure, supplements, and any medicines that may affect the result.

Reference range

Adult males: 7-56 U/L; Adult females: 7-43 U/LN/A

Specimen: urine

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated urinary cobalt-to-creatinine ratio may indicate increased cobalt absorption or exposure, often related to occupational contact. Interpretation can be affected by an incomplete collection, very dilute or concentrated urine, kidney function, recent exposure, and supplements containing cobalt.

Short name

24-Hour Urinary Cobalt Ratio

Frequently asked questions

Why is creatinine included in this test?
Creatinine helps account for differences in urine concentration. The ratio provides a more standardized way to interpret urinary cobalt than a single concentration.
How do I collect a 24-hour urine sample?
Collect all urine during the specified 24-hour period without missing a void. The laboratory should provide exact instructions, including when to begin and end collection and how to store the container.
Can diet or supplements affect the result?
Yes. Cobalt-containing supplements and certain occupational or environmental exposures can affect the result. Inform the laboratory and workplace health team about these possibilities.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy