Biomonitoring Summary

Benzophenone-3 (BP-3)

CAS No. 131-57-7

General Information

Benzophenone-3 (2-hydroxy-4-methoxybenzophenone) occurs naturally in some flowering plants. It is commercially synthesized as a sunscreen for use in lotions, conditioners, and cosmetics. It is also used as a UV stabilizer in plastic surface coatings and polymers.Benzophenone-3 is a common ingredient in sun-blocking agents.

People may be exposed through dermal application of sunscreens and cosmetic products.Small amounts of benzophenone-3 can be absorbed through human skin and excreted in the urine, mostly as a glucuronidated conjugate (Gonzalez et al., 2006; Gustavsson et al., 2002; Janjua et al., 2004; Ye et al., 2005). After dermal application of a 4% lotion over the entire body daily for 5 days, one study found that 1.2-8.7% of the applied benzophenone-3 amount was recovered in the urine (Gonzalez et al., 2006).

Human health effects from benzphenone-3 at low environmental doses or at biomonitored levels from low environmental exposures are unknown.Following dermal application, some cases of photoallergy or allergy to benzophenone-3 have been reported.Male reproductive toxicity has been inconsistently reported in chronic high dose animal studies (Daston et al., 1993; French, 1992).Benzophenone-3 has weak estrogenic activity or weak anti-androgenic activity (French, 1992; Schlecht et al., 2004; Schlumpf et al., 2001; Schreurs et al., 2005).No human hormonal changes were observed during four days of application of 10% benzophenone-3 lotion (Janjua et al., 2004).Benzophenone-3 is not considered mutagenic (Robison et al., 1994).IARC and NTP have no ratings as to human carcinogenicity of benzophenone-3.

Biomonitoring Information

Urinary benzophenone-3 levels include both conjugated and unconjugated forms and reflect recent exposure to the chemical. The NHANES 2003-2004 levels of urinary benzophenone-3 have been described by Calafat et al. (2008). The analysis showed that female participants had slightly higher urinary levels than males, and that non-Hispanic whites were more likely than non-Hispanic blacks to have levels above the 95th percentile of the overall population. Higher urinary benzophenone-3 levels also are apparent in non-Hispanic whites and females in NHANES 2005-2010 (CDC, 2012). In a study of 90 U.S. females aged 6-8 years, the median urinary benzophenone-3 level of 14.7 µg/L was comparable to the median levels of children 6-11 years of age (15.8-18.7 µg/L) in the NHANES 2003-2010 subsamples (Calafat et al., 2008; CDC, 2012; Wolff et al., 2007).Total benzophenone-3 urinary concentrations were detectable in 90% of a small sample of adults in whom the values ranged up to 3000 µg/L (Ye et al., 2005). Following short-term application of 10% benzophenone-3 lotion, men and women had mean urinary levels of 140 and 60 µg/L, respectively (Janjua et al., 2004).

Finding a measurable amount of benzphenone-3 in urine does not imply that the levels of benzphenone-3 cause an adverse health effect.Biomonitoring studies on levels of benzphenone-3 provide physicians and public health officials with reference values so that they can determine whether people have been exposed to higher levels of benzphenone-3 than are found in the general population.Biomonitoring data can also help scientists plan and conduct research on exposure and health effects.


Calafat AM, Wong LY, Ye X, Reidy JA, Needham LL. Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey 2003–2004. Environ Health Perspect 2008;116(7):893-897.

Centers for Disease Control and Prevention (CDC). Fourth National Report on Human Exposure to Environmental Chemicals. Updated Tables, 2012. [online] Available at URL: 10/16/12

Daston GP, Gettings SD, Carlton BD, Chudkowski M, Davis RA, Kraus AL, et al. Assessment of the reproductive toxic potential of dermally applied 2-hydroxy-4-methoxybenzophenone to male B6C3F1 mice. Fundam Appl Toxicol 1993;20(1):120-124.

French JE. NTP technical report on the toxicity studies of 2-hydroxy-4-methoxybenzophenone (CAS No. 131-57-7) Adminstered topically and in dosed feed to F344/N Rats and B6C3F1 mice.National Institutes of Health Publication No. 92-3344, October 1992 (also Toxic Rep Ser. 1992 Oct;21:1-E14).

Gonzalez H, Farbrot A, Larko O, Wennberg AM. Percutaneous absorption of the sunscreen benzophenone-3 after repeated whole-body applications, with and without ultraviolet irradiation. Br J Dermatol 2006;154(2):337-340.

Gustavsson Gonzalez H, Farbrot A, Larko O.Percutaneous absorption of benzophenone-3, a common component of topical sunscreens. Clin Exp Dermatol 2002;27(8):691-694.

Janjua NR, Mogensen B, Andersson AM, Petersen JH, Henriksen M, Skakkebaek NE, et al. 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. J Invest Dermatol 2004;123(1):57-61.

Okereke CS, Barat SA, Abdel-Rahman MS. Safety evaluation of benzophenone-3 after dermal administration in rats. Toxicol Lett 1995;80(1-3):61-67.

Robison SH, Odio MR, Thompson ED, Aardema MJ, Kraus AL. Assessment of the in vivo genotoxicity of 2-hydroxy 4-methoxybenzophenone. Environ Mol Mutagen 1994;23(4):312-317.

Schlecht C, Klammer H, Jarry H, Wuttke W. Effects of estradiol, benzophenone-2 and benzophenone-3 on the expression pattern of the estrogen receptors (ER) alpha and beta, the estrogen receptor-related receptor 1 (ERR1) and the aryl hydrocarbon receptor (AhR) in adult ovariectomized rats. Toxicology 2004;205(1-2):123-130.

Schlumpf M, Cotton B, Conscience M, Haller V, Steinmann B, Lichtensteiger W. In vitro and in vivo estrogenicity of UV screens. Environ Health Perspect 2001;109(3):239-244. Erratum in: Environ Health Perspect 2001;109(11):A517.

Schreurs RH, Sonneveld E, Jansen JH, Seinen W, van der Burg B. Interaction of polycyclic musks and UV filters with the estrogen receptor (ER), androgen receptor (AR), and progesterone receptor (PR) in reporter gene bioassays. Toxicol Sci 2005;83(2):264-272.

Ye X, Kuklenyik Z, Needham LL, Calafat AM. Quantification of urinary conjugates of bisphenol A, 2,5-dichlorophenol, and 2-hydroxy-4-methoxybenzophenone in humans by online solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. Anal Bioanal Chem 2005;383(4):638-644.

Page last reviewed: April 7, 2017