Used primarily as a biomarker for monitoring human exposure to polycyclic aromatic hydrocarbons (PAHs), especially from tobacco smoke, grilled foods, and environmental pollutants. It is a metabolite of benzo[a]pyrene, formed in the body during detoxification processes, and is measured in urine or blood to assess recent exposure to carcinogenic PAHs. Due to its role in metabolic studies, it also supports research on cancer risk assessment and the effectiveness of detoxification pathways. Not used in industrial or commercial products, but valuable in toxicological and epidemiological studies.