Benzophenone (BP)-type ultraviolet (UV) filters are estrogenic chemicals used extensively in sunscreen products, leading to concerns over human exposure. To assess exposure to BP derivatives in sunscreens, we tested 14 BP UV filters in 50 products representing 44 brands marketed in the United States in 2021, finding BP, 2-hydroxy-4-methoxybenzophenone (BP-3 or oxybenzone), 2,2'-dihydroxy-4-methoxybenzophenone (BP-8), 2-hydroxy-4-methoxy-4'-methylbenzophenone (BP-10), 2,3,4-trihydroxybenzophenone (2,3,4-OH-BP), and 4-methylbenzophenone (4-Me-BP) in ≥70% of the samples. The geometric mean (GM) concentration of the sum of these BPs (∑14BPs) in the 50 products was 6600 ng/g. BP-3 was the predominant BP in oxybenzone-containing products (accounting for >99% of the total concentration), with a concentration 5-6 orders of magnitude higher than that in "oxybenzone-free" products (GM: 35 600 000 vs 113 ng/g). BP was present in >90% of products analyzed, including those labeled "oxybenzone-free" (GM: 2100 ng/g). BP concentrations were ∼100-fold higher in octocrylene-containing vs "octocrylene-free" products (GM: 15900 vs 151 ng/g). Dermal exposure doses of BP-3 from oxybenzone-containing products (GM: 4140 000 ng/kg body weight (BW)/day) and of BP in some (24%) octocrylene-containing products (GM: 12 200 ng/kg BW/day) were above reference values (2 000 000 and 30 000 ng/kg BW/day for BP-3 and BP, respectively). This study provides evidence that BP and BP-3 concentrations in sunscreen products vary widely and may be noteworthy even in products labeled oxybenzone- or octocrylene-free, making dermal exposure a continuing concern.
Keywords: benzophenone; dermal exposure; octocrylene; oxybenzone; sunscreen.