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N-Methylformamide/Creatinine Ratio, Urine

Published: August 9, 2026Updated: August 16, 2026

A urine test that measures N-methylformamide relative to creatinine to help assess recent exposure to the industrial solvent N-methylformamide.

Quick summary

["An elevated result may indicate recent occupational exposure to N-methylformamide."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
56660-4
Short code
Mehyl Formamide/Creat Ur-Rto
Synonyms
Mehyl Formamide/Creat Ur-Rto
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 N-methylformamide (NMF) in urine and compares it with the amount of creatinine in the same sample. Creatinine is commonly used to help account for differences in urine concentration.

Why might I need this test?

This test may be used for workers exposed to NMF, a solvent used in some industrial processes. It can help determine whether the chemical is present in the body and may be used as part of workplace exposure monitoring.

How is the test performed?

A urine sample is collected and analyzed in a laboratory for NMF and creatinine. The laboratory then calculates the NMF-to-creatinine ratio. Collection is often timed to the end of a work shift or workweek, according to workplace testing instructions.

How do I prepare for the test?

Follow the collection instructions provided by your employer or laboratory, including the required collection time and urine container. Do not intentionally change your fluid intake. Tell the laboratory and healthcare professional if you have recently had unusual exposure to NMF or other chemicals.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine NMF/creatinine ratio

Frequently asked questions

What does NMF stand for?
NMF stands for N-methylformamide, an industrial solvent that can be absorbed through the skin, lungs, or digestive tract.
Why is creatinine included in the result?
Creatinine is measured to help adjust the urine NMF value for how concentrated or dilute the urine sample is.
When is the urine sample usually collected?
It may be collected at the end of a work shift or workweek to assess recent exposure. The exact timing should follow your employer's or laboratory's instructions.
  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 16, 2026. · Read our editorial policy