What test is used as the biological marker for exposure to toluene?

What test is used as the biological marker for exposure to toluene?

• A. Urine for Hippuric Acid
• B. Blood for phenol
• C. Hair for toluene
• D. Saliva tar

Answer: (A)

Biological monitoring of solvent exposure uses metabolites in urine to indicate what the body has processed. For toluene, the common marker is hippuric acid in urine. Toluene is metabolized in the liver to benzoic acid, which conjugates with glycine to form hippuric acid, and this is then excreted in urine. Measuring urinary hippuric acid provides a practical indicator of toluene exposure in many occupational settings. It’s historically the go-to test because it directly reflects the body's processing of toluene, making it the best-supported choice among the options. Keep in mind that hippuric acid can be influenced by other factors, such as dietary benzoates, so interpretation may consider context or additional markers if greater specificity is needed. The other tests—blood phenol, hair analysis for toluene, or saliva-based measures—aren’t standard markers for toluene exposure.

Biological monitoring of solvent exposure uses metabolites in urine to indicate what the body has processed. For toluene, the common marker is hippuric acid in urine. Toluene is metabolized in the liver to benzoic acid, which conjugates with glycine to form hippuric acid, and this is then excreted in urine. Measuring urinary hippuric acid provides a practical indicator of toluene exposure in many occupational settings. It’s historically the go-to test because it directly reflects the body's processing of toluene, making it the best-supported choice among the options. Keep in mind that hippuric acid can be influenced by other factors, such as dietary benzoates, so interpretation may consider context or additional markers if greater specificity is needed. The other tests—blood phenol, hair analysis for toluene, or saliva-based measures—aren’t standard markers for toluene exposure.