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Zinc Protoporphyrin (ZPP), Workplace

CPT: 84202
Updated on 11/21/2021
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  • Workplace ZPP
  • ZPP

Special Instructions

This test is for workplace monitoring. For nonworkplace monitoring, please order test 010170. Environmental and biological exposure indices (BEI) references will be listed on the report.1 For workplace exposure to lead, please refer to the BEI. Levels above the environmental exposure range are not always indicative of lead poisoning.

Note: This test is not intended for the evaluation of suspected porphyrias, including congenital erythropoietic porphyria. The Porphyrins, Evaluation, RBC test is intended for that purpose. This test is intended for the evaluation of suspected lead toxicity and iron deficiency anemia.

Expected Turnaround Time

2 - 4 days

Related Documents

Specimen Requirements


Whole blood


7 mL

Minimum Volume

0.2 mL


Royal blue-top (EDTA) tube or tan-top lead-free tube; submit original tube.


Mix tube thoroughly to avoid clotting.

Storage Instructions

Room temperature. Stable for five days at room temperature or for seven days when refrigerated.

Causes for Rejection

Clotted specimen; frozen specimen; hemolyzed specimen; icteric specimen

Test Details


Monitor chronic industrial exposure to lead


Fluorescent substances in plasma may interfere with hematofluorometer results.2 Skin contamination may lead to false elevations. Both this test and blood lead are needed for full evaluation.3-5



Reference Interval

Occupational exposure:

• ZPP, blood: Adults: 0−99 μg/dL: BEI® (sampling time is after one month's exposure)

Additional Information

"Free" protoporphyrin is noncomplexed, nonheme protoporphyrin. Lead poisoning is also characterized by elevated plasma and urine δ-aminolevulinic acid and increased urinary coproporphyrin. Urinary porphobilinogen and uroporphyrin are normal to slightly increased.3 Free erythrocyte protoporphyrin is a sensitive test for lead toxicity or chronic exposure in adults. Erythrocyte protoporphyrin levels should not be used as a screening test for lead poisoning in children.4 The diagnosis of lead exposure or poisoning includes consideration of environmental exposure, as well as symptoms and abnormal erythrocyte protoporphyrin.

Increased lead absorption is reported in the presence of iron deficiency.5


1. BEI® (Biological Exposure Indices) based on 1994-1995 Recommendations of the American Conference of Governmental Industrial Hygienists (ACGIH).
2. Marsh WL Jr, Nelson DP, Koenig HM. Free erythrocyte protoporphyrin (FEP) I. Normal values for adults and evaluation of the hematofluorometer. Am J Clin Pathol. 1983 Jun;79(6):655-660.6846255
3. Chisholm JJ. Increased lead absorption and lead poisoning. In: Behrman RE, Vaughan VC III, Nelson WE, eds. Nelson Textbook of Pediatrics. 13th ed. Philadelphia, Pa: WB Saunders Co;1987:1507-1511.
4. DeBaun MR, Sox HC Jr. Setting the optimal erythrocyte protoporphyrin screening decision threshold for lead poisoning: A decision analytic approach. Pediatrics. 1991 Jul,88(1):121-131.2057248
5. Carraccio CL, Bergman GE, Daley BP. Combined iron deficiency and lead poisoning in children. Effect on FEP levels. Clin Pediatr (Phila). 1987 Dec;26(12):644-647.3677534


Bird TD, Wallace DM, Labbe RF. The porphyria, plumbism, pottery puzzle. JAMA. 1982 Feb 12;247(6):813-814.7057560
Schreiber WE. Iron, porphyrin and bilirubin metabolism. In: Kaplan LA, Pesce AJ, eds. Clinical Chemistry−Theory, Analysis, and Correlation. 2nd ed. St Louis, Mo: Mosby-Year Book Inc; 1989:496-511.
Zanella A, Gridelli L, Berzuini A, et al. Sensitivity and predictive value of serum ferritin and free erythrocyte protoporphyrin for iron deficiency. J Lab Clin Med. 1989 Jan;113(1):73-78.2909654


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
010180 Zinc Protoporphyrin (ZPP) 012082 Zinc Protoporphyrin (ZPP) ug/dL 2895-1

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CPT Statement/Profile Statement

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