Sign in →

Test ID NICRU Nickel/Creatinine Ratio, Random, Urine

Reporting Name

Nickel/Creat Ratio, Random, U

Useful For

Urine nickel is the test of choice for detecting nickel toxicity in patients exposed to nickel carbonyl.

Profile Information

Test ID Reporting Name Available Separately Always Performed
NICR Nickel/Creat Ratio, U No Yes
CDCR Creatinine Conc No Yes

Specimen Type


Specimen Required

Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metals tests. If gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.

Supplies: Plastic, 10-mL urine tube (T068)

Specimen Volume: 3 mL

Collection Instructions:

1. Collect a random urine specimen in a plastic 10-mL urine tube (T068) or a clean, plastic aliquot container with no metal cap or glued insert

2. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Specimen Minimum Volume

1.2 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

0-17 years: not established

Males ≥18 years: <3.8 mcg/g creatinine

Females ≥18 years: <4.3 mcg/g creatinine

Day(s) and Time(s) Performed

Thursday; 8 a.m.

CPT Code Information

83885 Nickel Concentration

82570 Creatinine Concentration

LOINC Code Information

Test ID Test Order Name Order LOINC Value
NICRU Nickel/Creat Ratio, Random, U 13472-6


Result ID Test Result Name Result LOINC Value
CDCR Creatinine Conc 2161-8
32875 Nickel/Creat Ratio, U 13472-6

Clinical Information

Nickel (Ni), a silvery white metal widely distributed in the earth's crust, is essential for the catalytic activity of some plant and bacterial enzymes but its role in humans has not been defined. Elemental Ni may be essential for life at very low concentrations and is virtually nontoxic.


Nickel is commonly used in industry. It is a pigment in glass, ceramics and fabric dyes. It is converted in the Mond process to nickel carbonyl, NiCO(4), and used as a catalyst in petroleum refining and in the plastics industry, is frequently employed in the production of metal alloys (which are popular for their anticorrosive and hardness properties) in Ni-cadmium rechargeable batteries, and is used as a catalyst in hydrogenation of oils. NiCO(4) is very toxic.


NiCO(4), a liquid with low vapor pressure, is one of the most toxic chemicals known to man. NiCO(4) is absorbed after inhalation, readily crosses all biological membranes, and noncompetitively inhibits ATP-ase and RNA polymerase. NiCO(4) binds avidly to hemoglobin with resultant inability to take up oxygen. The affinity for hemoglobin is higher than carbon monoxide. The binding to hemoglobin is the main transport mechanism for spreading NiCO(4) throughout the body. Urine is the specimen of choice for the determination of Ni exposure via inhalation.


Patients undergoing dialysis are exposed to Ni and accumulate Ni in blood and other organs; there appear to be no adverse health effects from this exposure. Hypernickelemia has been observed in patients undergoing renal dialysis. At the present time, this is considered to be an incidental finding as no correlation with toxic events has been identified. Routine monitoring of patients undergoing dialysis is currently not recommended.


Breathing dust high in Ni content has been associated with development of neoplasms of the respiratory system and nasal sinuses. Most reactions to Ni are localized skin sensitivity and allergic skin disorders that occur on contact with Ni-containing alloys. These reactions do not correlate to urine concentrations; patients experiencing skin sensitivity reactions to Ni are likely to have normal Ni excretion.


Values of 3.8 mcg/g creatinine and higher for males, or 4.3 mcg/g creatinine and higher for females, represent possible environmental or occupational exposure.


Nickel (Ni) concentrations above 50 mcg/g creatinine are of concern, suggesting excessive exposure.


Clinical concern about Ni toxicity should be limited to patients with potential for exposure to toxic Ni compounds such as nickel carbonyl. Hypernickelemia, in the absence of exposure to that specific form of Ni, may be an incidental finding or could be due to specimen contamination.

Clinical Reference

1. Moreno ME, Acosta-Saavedra LC, Mez-Figueroa D, et al: Biomonitoring of metal in children living in a mine tailings zone in Southern Mexico: A pilot study. Int J Hyg Environ Health 2010;213:252-258

2. Schulz C, Angerer J, Ewers U, et al: Revised and new reference values for environmental pollutants in urine or blood of children in Germany derived from the German Environmental Survey on Children 2003-2006 (GerES IV). Int J Hyg Environ Health 2009;212:637-647

Analytic Time

1 day

Method Name

NICR: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

CDCR: Enzymatic Colorimetric Assay

Test Classification

See Individual Test IDs