Synthetic musks, which are widely used as fragrances in a variety of products, may pose a hidden threat to human health by enhancing the effect of compounds that are toxic, according to a study published recently in the peer-reviewed journal Environmental Health Perspectives (EHP). Researchers found that musk compounds inhibited natural defenses against toxicants in California mussels and that the effect remained long after exposure ended. Why worry about adverse effects in mussels?
We are exposed to musks through the skin when we use soaps and cosmetics, and wear clothes washed with scented detergents. We may also inhale musks through cologne sprays. Every year, approximately 8,000 metric tons of synthetic musks are produced worldwide.
Under normal circumstances, cells resist toxicants through proteins that keep foreign chemicals from entering cells. Using mussel gill tissue because its protein transporters are particularly active, the researchers incubated tissue for 90 minutes in a solution of musk compounds and a fluorescent dye. Finding the dye in the tissue would indicate that the defensive proteins were failing. The tissue remained compromised 48 hours after exposure for four of the six musk compounds tested.
The authors of the article are Till Luckenbach and David Epel of Hopkins Marine Station of Stanford University. They conclude their study especially points to the need to screen musks and other environmental chemicals that accumulate in humans to determine if they are also chemical sensitizers.
They wrote that especially critical is to ascertain whether musks cause long-term effects similar to those seen in their study and that such substances could result in unanticipated accumulation of toxicants in humans and confound safety predictions of seemingly innocuous chemicals.
Musks are used in foods as well as cosmetics. Here is a brief rundown from A Consumer's Dictionary of Food Additives and A Consumer's Dictionary of Cosmetic Ingredients:
MUSK. Musk acts as an odor carrier, improving and fortifying transportation of the vapors of other perfume materials. Natural musk, moschus moschiferus, is the dried secretion from the posterior part of an Asian deer's abdomen where a small sac situated immediately under the skin is filled with a thick fluid, abounding particularly in the rutting season. It is a brown, unctuous, smelly substance associated with attracting the opposite sex and which is promoted by stores for such purposes. In addition to cosmetics, it used in food flavorings and at one time was employed as a stimulant and nerve sedative in medicine. Natural musk can cause allergic reactions.
MUSK AMBRETTE . A synthetic musk widely used as a fragrance ingredient in perfumes, soaps, detergents, creams, lotions, and dentifrices in the United States at an estimated 100,000 pounds per year. Musk ambrette had been used in fragranced products since before the 1920s. In 1967, it was reportedly found to damage the myelin, the covering of nerve fibers. This was first discovered when mice were fed varying levels of musk ambrette. Since dietary consumption of musk ambrette is generally very low, the impact was discounted and no assessment was made of exposures from fragranced products. In 1985, after studies were published on the neurotoxic effect and it was determined that the musk ambrette was readily absorbed through the skin, the fragrance industry, itself, recommended that musk ambrette not be used in direct skin contact products. Musk ambrette can also cause sensitivity to light and contact dermatitis, especially in after-shave lotions. Musk tetralin, in use for twenty years as a fragrance ingredient, was identified as a neurotoxin and removed from the market in 1978. Musk Ambrette is still used as in food but not in cosmetics and has been generally recognized as safe (GRAS) for foods by the FDA.
MUSK MOSKENE .A soft, sweet fragrance resembling musk ambrette. It is a creamy powder and is used in fragrances. It costs less than other musks and is not as sensitive to sunlight. It is therefore being increasingly employed. Rouges and perfumes containing musk moskene have been reported to cause hyperpigmentation (brown spots) on the skin of some people. The hyperpigmentation slowly disappeared after discontinuation of the products
LABDANUM . A synthetic musk used in perfumes, especially as a fixative, is a volatile oil obtained by steam distillation from gum extracted from various rockrose shrubs. Golden yellow, viscous, with a strong balsamic odor and a bitter taste, it is also employed as a food additive in raspberry, fruit, and vanilla flavorings for beverages, ice cream, ices, candy, baked goods, gelatin desserts, and chewing gum. Mildly toxic by ingestion. It has also been noted as a skin irritant. While it has been reported in use the FDA, has not yet designated it for a search of the toxicology literature.
ACETYL HEXAMETHYL TETRALIN . A synthetic musk used mostly in cosmetics but in some food additives. It is closely related to acetyl ethyl tetramethyl tetralin, which was voluntarily removed from perfumes when it was reported to cause nerve damage in animals. The "hexa" component was inserted to make the fragrances less volatile and less allergenic
MUSK, KETONE. A synthetic compound with a typical musk odor is widely used in cosmetics and is permitted as a food additive. Exposure to it, experiments in animals and with human cells indicate it might increase the susceptibility to health hazards caused by cancer causing agents humans.
Although the latest warning about synthetic musk was in EHP, published by the National Institute of Environmental Health Sciences, part of the U.S. Department of Health and Human Services, whether any action will be taken on these widely used substances in our food and cosmetics is doubtful unless there is some consumer action.