Musk Xylene - Production and Use

Production and Use

Musk xylene is produced from meta-xylene (1,3-dimethylbenzene), by a Friedel–Crafts alkylation with tert-butyl chloride and aluminium chloride followed by nitration with fuming nitric acid or with a 70:30 mixture of nitric acid and sulfuric acid. The crude product is recrystallized from 95% ethanol.

Musk xylene has been used in a wide variety of consumer products since the early 1900s, usually in very small quantities. World production of nitro musks in 1987 was about 2500 tonnes, but had fallen to about 1000 tonnes by the early 1990s: musk xylene made up roughly two-thirds of the production of nitro musks during this period. Production was concentrated in Western Europe, with the United Kingdom alone accounting for 28% of world production of nitro musks.

Use of musk xylene continued to decline through the 1990s, as fragrance manufacturers voluntarily switched to alternative fragrance compounds. For example, musk xylene has not been used in Japanese products (on a voluntary basis) since 1982, and the Association of the German Toiletries and Detergents Industry (IKW) recommended the replacement of musk xylene by another compound in 1993. Production of musk xylene in the European Union came to a halt and, by 2000 (the last year for which full data are available), imports to Europe were only 67 tonnes, with China as the most important source. The estimated 2008 usage of musk xylene in the European Union was 25 tonnes.

Musk xylene is still permitted for use in cosmetics products (except oral care products) in the European Union under the Cosmetics Directive. The permitted quantities are: up to 1% in fine fragrances; up to 0.4% in eau de toilette; up to 0.03% in other products. European Union suppliers must inform their customers on request if a product contains more than 0.1% by weight of musk xylene.