Oxidant/PCC tests for the presence of oxidizing reagents such as bleach, hydrogen peroxide, and pyridinium chlorochromate (PCC). Like nitrites, oxidants work to modify the structure of the target drugs in urine (like THCCOOH). Many commercial adulterants contain oxidants or PCC. Examples include UrineLuck (PCC) and Stealth (peroxidase). Normal urine should contain no trace of oxidants/PCC.

Nitrites are a class of chemicals not usually found in normal human urine. Commercial adulterants Klear and Whizzies use nitrites as their primary active ingredient. Nitrites work by oxidizing the major cannabinoid metabolite (THCCOOH). The intent of oxidizing THC-COOH is to render it undetectable by the  immunoassay or confirmation methods. Recent research suggests that performing the immunoassay drug screen shortly after the urine collection limits the effectiveness of the nitrite since the chemical needs time to modify the THC-COOH compound. By the time a positive sample arrives to the lab for confirmation, however, the THC-COOH has often been destroyed. Normal human urine should contain no trace of nitrites and, as such, presence of nitrites in urine generally indicates the use of an adulterant.