ABSTRACT
The literature on phototoxicity contains an assortment of data involving a wide variety of compounds, test methods, equipment, and results. T. Maurer reviewed and studied the published findings on humans and animals and voiced concern about the complexities of phototoxicity testing and the limitations of the predictability of test results. Radiation sources that deliver highly energetic shorter wavelengths in the UVC range are unlikely to be useful in experimental phototoxicity studies involving humans. The photoactive chemical may reach the target tissues either after direct application or indirectly via the blood stream, following ingestion or parenteral administration. The skin response is characterized by erythema and sometimes edema, vesiculation, and pigmentation. Screening tests for evaluating phototoxic potential should, therefore, begin with an examination of the test chemical under ultraviolet radiation. Psoralens are among the most frequently involved phototoxic chemicals, as they are present in many plants.
