Zinc Protoporphyrin, Blood

ZPP, Protoporphyrin, Zinc, Free Erythrocyte Protoporphyrin

Test Codes

EPIC: LAB1231931, Beaker: Zinc, ZPP, WB, Quest: 948

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Royal Blue-top EDTA tube.

Physician Office/Draw Specimen Preparation

Do not centrifuge or freeze. Maintain whole blood at room temperature (20-26°C or 68-78.8°F) prior to transport.

Preparation for Courier Transport

Transport: 2.0 mL whole blood at room temperature (20-26°C or 68-78.8°F). (Minimum: 0.5 mL/Pediatric 0.2 mL)

Rejection Criteria

• Frozen specimens.
• Clotted specimens.
• Hemolyzed specimens.
• Specimens not collected and processed as indicated. 

In-Lab Processing

Do not centrifuge or freeze. Maintain whole blood at room temperature (20-26°C or 68-78.8°F) prior to transport.

Transport: 1.0 mL whole blood at room temperature (20-26°C or 68-78.8°F). (Minimum: 0.5 mL/Pediatric 0.2 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 4 days
Refrigerated (2-8°C or 36-46°F): 10 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Tuesday – Saturday.
Results available in 2 days.

Reference Range

Industrial Exposure: <100 mcg/dL
(Refer to current OSHA regulation for exposure criteria.)

Test Methodology

Hematofluorometry

Interpretation

For occupational exposure to lead, OSHA requires ZPP whole blood testing reported in units of mcg/dL. For adults, conversion of ZPP units of mcg/dL assumes a hematocrit of 45%.

Clinical Utility

Elevated ZPP results are seen in early and late iron deficiency, in the anemia of chronic disease erythropoietic protoporphyria, and in chronic lead poisoning (typically when blood lead is greater than 25 mcg/dL). Causes for false elevations include markedly elevated bilirubin and riboflavin. Elevated protoporphyrin (as in erythropoietic protoporphyria) can also increase the ZPP signal. Specimens which are hemolyzed, clotted, or improperly aliquoted can also show false elevations.

CPT Codes

84202
LOINC:  33007

Contacts

Last Updated

11/19/2025