Salzberg Chemistry Seminar: Prof. Laura MacManus-Spencer
Mon, Nov 18
12:00 PM — 1:00 PM
Marshak Hall160 Convent Avenue
Marshak Hall, 1027
What happens to that sunscreen cream after your use it?Prof. Laura MacManus-Spencer of Union College in Schenectady, NY will present the topic, "What happens to that suncreen cream after you use? - the photochemical fate of sunscreen chemicals in the aquatic environment."
Ultraviolet (UV) filter chemicals are the active ingredients used in sunscreens, lotions, lip balms and other personal care products intended for protection from UV light from
the sun. Though UV filter chemicals are designed to remain photostable, several are known to degrade upon exposure to UV light, which has implications both for their effectiveness in sunscreen products and for their fate in the aquatic environment. In this study, the aqueous photolysis of several UV filter chemicals is investigated; this presentation will focus on two commonly used chemicals –
octyl methoxycinnamate (Octinoxate) and octyldimethyl para-aminobenzoic acid (Padimate O). Experiments are conducted under natural and simulated sunlight to determine the kinetics and mechanism of direct photolysis
and the importance of indirect photolysis. The relative importance of indirect photolysis is investigated by conducting photolysis experiments in the presence of varying concentrations of well characterized humic and
fulvic acids. In addition, the pH dependence of direct photolysis is investigated. Liquid chromatography – mass spectrometry is used to identify the products of direct photolysis. The data obtained in this study may be used to
assess the fates of UV filter chemicals in the aquatic environment and to make informed decisions about their use in consumer products.