Risk assessment of diethylamino hydroxybenzoyl hexyl benzoate (DHHB) as a UV filter in cosmetics

Diethylamino hydroxybenzoyl hexyl benzoate (DHHB) is a UVA filter widely used in cosmetic formulations. The present study evaluated the toxicological profile and conducted a human health risk assessment of DHHB based on available toxicological and exposure data. Overall, the available studies indicate low acute toxicity, no evidence of genotoxicity, and minimal skin irritation or sensitization potential. For risk characterization, the maternal no-observed-adverse-effect level (NOAEL) of 200 mg/kg bw/day derived from a reproductive and developmental toxicity study in rats was selected as the point of departure because it represents the most relevant endpoint for systemic exposure. Human exposure was estimated using the cosmetic exposure assessment approach recommended by the Ministry of Food and Drug Safety (MFDS). The systemic exposure dose (SED) was calculated assuming daily use of sunscreen products (17 g/day), a maximum DHHB concentration of 10%, and a dermal absorption rate of 0.15%. Based on these parameters, the SED was estimated to be 0.0425 mg/kg bw/day. Comparison of the SED with the selected NOAEL yielded a margin of safety (MoS) of 4,705, which exceeds the safety threshold of 100 typically applied in cosmetic risk assessments. These results indicate that DHHB presents a low risk to human health when used as a UV filter in cosmetic products at concentrations up to 10%.