Urinary BPA, DETP, PFBA, and 2-HPMA indicate recent exposure to BPA, organophosphate pesticides, short-chain PFAS, and propylene oxide.

The four urinary analytes are scientifically supported biomarkers of exposure, but all principally reflect recent exposure and require context before inferring source, dose, or health risk.

Clinical and exposure-assessment evidence

• Total urinary BPA is an established marker of recent internal BPA exposure. BPA is rapidly converted mainly to glucuronide, and less to sulfate, conjugates and substantially excreted in urine; reported elimination half-lives are approximately 2–6 hours.
• Urinary DETP supports recent exposure related to the organophosphate pesticide class, but not to a particular pesticide. It commonly reflects exposure over roughly the preceding day, although some occupational metabolites have been detected through day 4 after spraying.
• Urinary PFBA indicates recent exposure to PFBA or PFBA-forming short-chain PFAS precursors, rather than long-term PFAS body burden.
• Urinary 2-HPMA credibly indicates recent propylene oxide uptake. It is not a toxicity marker or health-risk threshold.

Mechanistic interpretation

• BPA’s urinary conjugates arise from rapid hepatic metabolism.
• DETP may result either from metabolism of several diethyl organophosphates or direct ingestion of preformed dietary/environmental dialkyl phosphates.
• PFBA is excreted largely unchanged and can be formed from precursors such as 6:2 fluorotelomer alcohol.
• Propylene oxide conjugates with glutathione and is metabolized to the mercapturic acid 2-HPMA. Tobacco smoke materially contributes: urinary 2-HPMA fell 52% after four weeks of smoking cessation.

Practical interpretation

• Spot samples vary with timing, urine dilution, and recent exposures; creatinine or specific-gravity adjustment and repeated sampling improve characterization.
• Detection does not establish cumulative dose, a specific exposure source, clinical disease, or toxicologically meaningful risk.

Bottom line

• These are valid biomarkers for their stated exposure categories, especially for recent exposure, but none should be interpreted alone as a source-specific, long-term, or health-risk measurement.