Synthetic musks are a large, poorly-studied class of chemicals added as scents to cosmetics, including perfumes, lotions and many other personal care products. Several studies suggest some of these compounds may disrupt hormone systems or trigger skin sensitization when exposed to UV light (i). Synthetic musks identified in fragrances have been found in the cord blood of newborn babies (ii), as well as in blood, breast milk and body fat.
Products That May Contain Synthetic Musks
Two types of musks have historically been used in fragrances, cosmetics and personal care products: nitromusks, such as musk ketone, and polycyclic musks, such as Galaxolide and Tonalide. Synthetic musks are widely used as scents in personal care products and are found in many perfume, lotions, colognes and body sprays.
There is evidence that exposure to synthetic musks can have hormone disrupting effects. Galaxolide and Tonalide can bind to and stimulate human estrogen receptors (iii), and both musks have been shown to affect androgen and progesterone receptors (iv). Tonalide has also been reported to increase the proliferation of estrogen-responsive human breast cancer cells (v). Further, Tonalide has been identified as a photosensitizer, a chemical that becomes more toxic when exposed to sunlight on the skin (vi) and has been linked to liver toxicity (vii).
Due to the ubiquity of these chemicals, synthetic musks are pervasive in people’s bodies—even in newborns. Environmental Working Group tests of umbilical cord blood found 7 out of 10 babies had been born with Tonalide and/or Galaxolide in their blood (ii). Another study detected Galaxolide in the blood of 91 percent of Austrian students.
Several studies have specifically linked personal care products with elevated body levels of synthetic musks. A 1996 study found Galaxolide and Tonalide in body fat and breast milk after use of cosmetics and detergents (viii). A survey on routes of exposure linked body lotion to higher Galaxolide concentrations (ix, x), and another study found frequent use of perfume during pregnancy resulted in elevated concentrations of Galaxolide in breast milk (xi).
Synthetic Musk fragrances are produced in high volumes (industry reported manufacturing or importing between 1 and 10 million pounds of Galaxolide in 2006 alone (xii)) and can accumulate in the food chain and negatively impact the environment (xiii). Environmental studies from areas as diverse as the Great Lakes, Germany and China have documented widespread Galaxolide and Tonalide contamination of both fresh and marine water samples, air, wastewater and sludge (xiv, xv). Studies also report Galaxolide and Tonalide contamination in many species of aquatic wildlife (xvi).
The combination of widespread human exposure, environmental contamination and persistence raises questions about the safety of their widespread use in fragranced products. Reducing the volume of fragranced products in daily use could make a significant difference to pollution in people and the environment.
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iv. Schreurs RH, Sonneveld E, Jansen JH, Seinen W, van der Burg B. 2005. 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. 83(2): 264-72.
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viii. Rimkus, G.G. and M. Wolf, Polycyclic musk fragrances in human adipose tissue and human milk. Chemosphere, 1996. 33(10): p. 2033-43.
ix. Hutter HP, Wallner P, Moshammer H, Hartl W, Sattelberger R, Lorbeer G, Kundi M. 2005. Blood concentrations of polycyclic musks in healthy young adults. Chemosphere. 59(4): 487-92.
x. Hutter, HP, P Wallner, H Moshammer, W Hartl, R Sattelberger, G Lorbeer and M Kundi. 2009. Synthetic musks in blood of healthy young adults: Relationship to cosmetics use. Science of the Total Environment 407:4821-4825.
xi. Lignell S, Darnerud PO, Aune M, Cnattingius S, Hajslova J, Setkova L, Glynn A. 2008. Temporal trends of synthetic musk compounds in mother’s milk and associations with personal use of perfumed products. Environ Sci Technol. 42(17): 6743-8.
xii. U.S. Environmental Protection Agency (USEPA). 2009a. Inventory Update Reporting (IUR) Data for 2006. Available: http://www.epa.gov/iur/
xiii. Dietrich DR and Hitzfeld BC. 2004. Bioaccumulation and Ecotoxicity of Synthetic Musks in the Aquatic Environment. In: The Handbook of Environmental Chemistry, volume 3, part X: 233-244 (Springer Berlin/Heidelberg).
xiv. Chen D, Zeng X, Sheng Y, Bi X, Gui H, Sheng G, Fu J. 2007. The concentrations and distribution of polycyclic musks in a typical cosmetic plant. Chemosphere. 66(2):252-8.
xv. Rüdel H, Böhmer W, Schröter-Kermani C. 2006. Retrospective monitoring of synthetic musk compounds in aquatic biota from German rivers and coastal areas. J Environ Monit. 8(8): 812-23.
xvi. Kannan K. Reineer JL, Yun SH. Perotta EE, Tao L, Johnson-Restrepo B, Rodan BD. 2005. Polycyclic musk compounds in higher trophic level aquatic organisms and humans from the United States. Chemosphere 61: 693–700.