chemical information

CAS RN:

81-15-2

Chemical Class:

Musks

Chemical SubClass

Nitro Musks

Found in these people:

Anonymous Adult 5, Anonymous Adult 12, Anonymous Adult 11

Found in these locations:

Fredericksburg, VA; Mountain View, CA; Palo Alto, CA

Exposure routes:

Synthetic musk fragrance found in detergents, fabric softeners, soaps.

Summary

Musk xylene is a synthetic musk and a member of the nitromusk family. Production and use of this chemical has decreased drastically in recent years due to concerns about its toxicity and persistence in the environment, and the resulting mandatory or voluntary bans in effect throughout much of Europe (OSPAR 2004).

Musk xylene is still in use in the U.S., primarily as a fragrance in detergents, fabric softeners, and soaps. Exposure to musk xylene can occur through dermal contact, inhalation, and ingestion; dermal absorption and inhalation are especially important routes of exposure, given the number of cleansing products and cosmetics that contain synthetic musks (Daughton 1999).

Nitromusks are lipophilic, or "fat-loving," and tend to bioaccumulate in people and other animals (Suter-Eichenberger 1998; Daughton 1999); musk xylene in particular is commonly found in the breast milk, adipose tissue, and blood of people (Liebl 1993, 2000; Rimkus 1994; Muller 1996; TNO 2004, 2005). It is also a common contaminant in rivers and lakes and in aquatic organisms (Daughton 1999; Fromme 1999; Peck 2004; Duedahl-Olesen 2005).

Nitromusks enter the environment when they are washed down the sink, and are discharged into rivers and lakes through treated wastewater or sewage sludge. From there, these chemicals are ingested by aquatic organisms, and bioaccumulate in fish and shellfish (Daughton 1999; Fromme 2001; Duedahl-Olesen 2005).

Though musk xylene is a widely-used nitromusk, little information is available on its toxicity in humans. When applied to the skin, musk xylene can induce a weak sensitizing effect (Parker 1986). High serum levels of musk xylene in women may be associated with gynecological abnormalities, including mild insufficiency of the ovaries and compromised fertility (Eisenhardt 2001). In addition, a study probing the estrogenic activity of musk xylene documented proliferation of isolated human breast cancer cells upon treatment with the chemical, providing limited evidence that musk xylene may disrupt the human endocrine system (Bitsch 2002).

Animal studies indicate that musk xylene may have carcinogenic properties (Maekawa 1990; Apostolidis 2002). In particular, liver cancer observed in rats treated with musk xylene may be caused by the ability of this chemical to induce specific cytochrome P450 enzymes linked to cancer (Lehman-McKeeman 1999). Further studies indicate musk xylene causes toxic effects in some aquatic organisms (Chou 1999b; Carlsson 2004). Amino metabolites of musk xylene, commonly detected in aquatic organisms and ecosystems (Rimkus 1999), also demonstrate estrogenic effects (Chou 1999a).

Musk xylene has also been found to have effects on cell wall transporters in marine mussels, which can result in accumulation of toxic molecules (Luckenbach 2005). These same cell wall transporters are found in human tissue as well; further studies should be conducted to investigate any implications of these findings for human health (Luckenbach 2005).

Musk xylene

Synthetic fragrance in detergents, fabric softeners, soaps. Can irritate the skin and bioaccumulate in people. Suspected hormone disruptor. Causes cancer in lab animals.

Musk xylene has been found in 3 of the 52 people tested in EWG/Commonweal studies.

Top health concerns for Musk xylene (References)

health concern or target organ	weight of evidence
Cancer	limited
Endocrine system	limited

Other health concerns for Musk xylene (References)

health concern or target organ	weight of evidence
Reproduction and fertility	limited
Immune system (including sensitization and allergies)	possible
Skin	limited
Chronic effects, general	unknown

Results for Musk xylene

Musk xylene was measured in different units for some of the studies. Overall it was found in 3 of 52 people tested in EWG/Commonweal studies. The bars below are grouped by units:

in blood serum (wet weight)

Showing results from EWG/Commonweal Study #7, consumer product chemicals in adults and teens, EWG Study #10, cosmetic chemicals in teens, Adult Minority Leader Report, Other Body Burden Studies

EWG/Commonweal results

• geometric mean: 0.0333 ng/g (wet weight) in blood serum
• found in 3 of 42 people in the group

	ng/g (wet weight) in blood serum	0.19

in whole blood (wet weight)

Showing results from Pollution in Minority Newborns

EWG/Commonweal results

• found in 0 of 10 people in the group

found in 0 of 10 people

Detailed toxicity classifications (References)

classification	governing entity/references
Cancer - limited evidence of carcinogenicity	Apostolidis, S., T. Chandra, et al. (2002). "Evaluation of carcinogenic potential of two nitro-musk derivatives, musk xylene and musk tibetene in a host-mediated in vivo/in vitro assay system." Anticancer Res 22(5): 2657-62.
Endocrine disruptor - suspected or limited evidence	Bitsch, N., C. Dudas, et al. (2002). "Estrogenic activity of musk fragrances detected by the E-screen assay using human mcf-7 cells." Arch Environ Contam Toxicol 43(3): 257-64.
Endocrine disruptor - suspected or limited evidence	Chou, Y. J. and D. R. Dietrich (1999). "Interactions of nitromusk parent compounds and their amino-metabolites with the estrogen receptors of rainbow trout (Oncorhynchus mykiss) and the South African clawed frog (Xenopus laevis)." Toxicol Lett 111(1-2): 27-36.
Limited evidence in humans - endocrine system toxicity	Eisenhardt, S., B. Runnebaum, et al. (2001). "Nitromusk compounds in women with gynecological and endocrine dysfunction." Environ Res 87(3): 123-30.
Reproductive toxicant - limited evidence	Eisenhardt, S., B. Runnebaum, et al. (2001). "Nitromusk compounds in women with gynecological and endocrine dysfunction." Environ Res 87(3): 123-30.
Cancer - limited evidence of carcinogenicity	Maekawa, A., Y. Matsushima, et al. (1990). "Long-term toxicity/carcinogenicity of musk xylol in B6C3F1 mice." Food Chem Toxicol 28(8): 581-6.
Skin sensitizer	Parker, R. D., E. V. Buehler, et al. (1986). "Phototoxicity, photoallergy, and contact sensitization of nitro musk perfume raw materials." Contact Dermatitis 14(2): 103-9.
Limited evidence in humans - skin toxicity	Parker, R. D., E. V. Buehler, et al. (1986). "Phototoxicity, photoallergy, and contact sensitization of nitro musk perfume raw materials." Contact Dermatitis 14(2): 103-9.
Chronic effects, general - weight of evidence unknown/unassessed	Luckenbach, T. and D. Epel (2005). "Nitromusk and polycyclic musk compounds as long-term inhibitors of cellular xenobiotic defense systems mediated by multidrug transporters." Environ Health Perspect 113(1): 17-24.