What might cause an oxidant positive result in specimen validity testing?

• A. Expired reagents
• B. Low creatinine
• C. Proteinuria
• D. Presence of oxidants in adulterants such as nitrite or bleach

Answer: (D)

The key idea is that the oxidant test in specimen validity checks detects substances that can oxidize the test reagents. When adulterants containing oxidizing agents are added to urine, such as nitrite or household bleach, they produce a positive signal on the oxidant test pad. This indicates the sample may have been tampered with, rather than reflecting a normal urine composition.

Expired reagents could lead to unreliable results in general, but they don’t specifically explain an oxidant-positive finding. Low creatinine points to dilution, not oxidation, and proteinuria reflects protein in the urine, not the presence of oxidants.