Photochemistry of Urocanic Acid: Evidence that Urocanic Acid Should be Used with Caution in Cosmetic Formulations

---

Kerry M. Hanson and John D. Simon

---

Data from a previously reported spectroscopic investigation of urocanic acid are summarized. The data support the conclusion that urocanic acid should be used with caution as an ingredient in sunscreen and conditioning cosmetic formulations because reactive intermediates can be produced following absorption of the sun's lower UV-B wavelengths.

---

Journal of the Society of Cosmetic Chemists, volume 48, p. 151 (1997)

---