Systemic Absorption of the Sunscreens Benzophenone-3, Octyl-Methoxycinnamate, and 3-(4-Methyl-Benzylidene) Camphor After Whole-Body Topical Application and Reproductive Hormone Levels in Humans

Abstract

Recent in vitro and animal studies have reported estrogen-like activity of chemicals used in sunscreen preparations. We investigated whether the three sunscreens benzophenone-3 (BP-3), octyl-methoxycinnamate (OMC), and 3-(4-methylbenzylidene) camphor (4-MBC) were absorbed and influenced endogenous reproductive hormone levels in humans after topical application. In this 2-wk single-blinded study 32 healthy volunteers, 15 young males and 17 postmenopausal females, were assigned to daily whole-body topical application of 2 mg per cm(2) of basic cream formulation without (week 1) and with (week 2) the three sunscreens at 10% (wt/wt) of each. Maximum plasma concentrations were 200 ng per mL BP-3, 20 ng per mL 4-MBC, and 10 ng per mL OMC for females and 300 ng per mL BP-3, 20 ng per mL 4-MBC, and 20 ng per mL OMC for men. All three sunscreens were detectable in urine. The reproductive hormones FSH, LH were unchanged but minor differences in testosterone levels were observed between the 2 wk. A minor difference in serum estradiol and inhibin B levels were observed in men only. These differences in hormone levels were not related to sunscreen exposure.

Paraben esters: review of recent studies of endocrine toxicity, absorption, esterase and human exposure, and discussion of potential human health risks

“…Thus common coingredients in cosmetic formulations may interact in mixtures, resulting in higher skin and body burdens of parabens [and other endocrine active compounds common in cosmetics, e.g. phthalates (Jobling et al, 1995;Harris et al, 1997;Okubo et al, 2003), polycyclic musks (Gomez et al, 2005;Schreurs et al, 2005), UV ¼lters (Schlumpf et al, 2001;Inui et al, 2003;Janjua et al, 2004;Koda et al, 2005), aluminium chlorhydrate (Darbre, 2006b), triclosan (Gee et al, 2008) and cyclosiloxanes (McKim et al, 2001;He et al, 2003)]. …”

“…It is also important to note that Janjua and colleagues have shown other oestrogenic chemicals commonly found in bodycare cosmetics to also be absorbed systemically from whole body topical application of cosmetic creams. This includes phthalates (Janjua et al, 2007) and the sunscreens benzophenone-3, octyl-methoxycinnamate and 3-(4-methyl-benzylidene) camphor (Janjua et al, 2004). Thus, real-life repeated dermal exposures to the range of paraben esters, and other oestrogenic co-formulants in body care cosmetics, could provide signi¼cant additional oestrogenic stimulation in the human body.…”

Ultraviolet Radiation: A Hazard to Children and Adolescents

“…128 A study in young men and postmenopausal women given generous daily applications of benzophenone 3, OMC, and 4-MBC revealed detectable levels of these chemicals in plasma and urine. 129 There were no effects on serum concentrations of reproductive hormones related to sunscreen exposure in men or women. The authors concluded that although the data showed skin penetration of these sunscreen chemicals, there did not seem to be an effect on the hypothalamic-pituitary-gonadal axis.…”

Disruption of Thyroid Hormone Function by Environmental Pollutants

“…[88][89][90] Being highly lipophilic and easily bioaccumulated are readily released into lakes and rivers via swimming and wastewater, 91,92) and then accumulate in fish. 93,94) Humans are exposed to UV screens directly from cosmetics, 95,96) or indirectly through the food chain, and residues of several UV filters have been detected in human milk. 97) Schmutzler et al 98) reported that the UV filter benzophenone 2 (BP2) interfered with TH homeostasis in rats.…”