Next Generation Risk Assessment for Benzophenone-4 in Sunscreen

This technical report presents a case study on the Next Generation Risk Assessment (NGRA) of Benzophenone-4 (BP-4), a chemical used as a UV filter in sunscreen products. The objective is to evaluate whether a tiered NGRA approach can effectively assess the safety of BP-4 at the maximum approved concentration of 5%. The report outlines the methodology, including the assessment of systemic toxicity using New Approach Methods (NAMs) and the absence of in vivo animal data. It details the exposure assessment, highlighting the dermal application of sunscreen and the resulting internal concentrations through physiologically-based kinetic (PBK) modeling. The report discusses the in silico tools utilized for toxicity endpoints and the findings regarding BP-4's bioactivity and potential estrogen receptor binding. Furthermore, it addresses the renal clearance and distribution of BP-4 in the human body, concluding that only a small amount enters systemic circulation, with low tissue distribution and negligible liver clearance. The report emphasizes the importance of understanding BP-4's kinetic behavior for consumer safety.