Perfume

Perfume is a mixture of fragrant essential oils and aroma compounds, fixatives, and solvents used to give the human body, animals, objects, and living spaces a pleasant scent [1]. The odoriferous compounds that make up a perfume can be manufactured synthetically or extracted from plant or animal sources.

Perfumes have been known to exist in some of the earliest human civilisations either through ancient texts or from archaeological digs. Modern perfumery began in the late 1800s with the commercial synthesis of aroma compounds such as vanillin or coumarin, which allowed for the composition of perfumes with smells previously unattainable solely from natural aromatics alone.

Contents

History

Egyptian scene depicting the preparation of Lily perfume
Etruscan perfume vase shaped like a female head

The word perfume used today derives from the Latin "per fumus", meaning through smoke. Perfumery, or the art of making perfumes, began in ancient Mesopotamia and Egypt and was further refined by the Romans and Persians.

Although perfume and perfumery also existed in India, much of its fragrances are incense based. The earliest distillation of Attar was mentioned in the Hindu Ayurvedic text Charaka Samhita. The Harshacharita, written in 7th century A.D. in Northern India mentions use of fragrant agarwood oil.

The world's first recorded chemist is considered to be a woman named Tapputi, a perfume maker who was mentioned in a cuneiform tablet from the second millennium BC in Mesopotamia.[2] She distilled flowers, oil, and calamus with other aromatics then filtered and put them back in the still several times.[3]

In 2005[4], archaeologists uncovered what are believed to be the world's oldest perfumes in Pyrgos, Cyprus. The perfumes date back more than 4,000 years. The perfumes were discovered in an ancient perfumery. At least 60 stills, mixing bowls, funnels and perfume bottles were found in the 43,000-square-foot (4,000 m2) factory.[5] In ancient times people used herbs and spices, like almond, coriander, myrtle, conifer resin, bergamot, as well as flowers.[6]

The Arabian chemist, Al-Kindi (Alkindus), wrote in the 9th century a book on perfumes which he named Book of the Chemistry of Perfume and Distillations. It contained more than a hundred recipes for fragrant oils, salves, aromatic waters and substitutes or imitations of costly drugs. The book also described 107 methods and recipes for perfume-making and perfume making equipment, such as the alembic (which still bears its Arabic name).[7]

The Persian chemist Ibn Sina (also known as Avicenna) introduced the process of extracting oils from flowers by means of distillation, the procedure most commonly used today. He first experimented with the rose. Until his discovery, liquid perfumes were mixtures of oil and crushed herbs or petals, which made a strong blend. Rose water was more delicate, and immediately became popular. Both of the raw ingredients and distillation technology significantly influenced western perfumery and scientific developments, particularly chemistry.

The art of perfumery was known in western Europe ever since the 1221 if we consider the monks' recipes of Santa Maria delle Vigne or Santa Maria Novella of Florence, Italy. In the east, the Hungarians produced in 1370 a perfume made of scented oils blended in an alcohol solution at the command of Queen Elizabeth of Hungary best known as Hungary Water. The art of perfumery prospered in Renaissance Italy, and in the 16th century, Italian refinements were taken to France by Catherine de' Medici's personal perfumer, Rene the Florentine (Renato il fiorentino). His laboratory was connected with her apartments by a secret passageway, so that no formulas could be stolen en route. Thanks to Rene, France quickly became one of the European centers of perfume and cosmetic manufacture. Cultivation of flowers for their perfume essence, which had begun in the 14th century, grew into a major industry in the south of France. Between the 16th and 17th century, perfumes were used primarily by the wealthy to mask body odors resulting from infrequent bathing. Partly due to this patronage, the perfumery industry was created. In Germany, Italian barber Giovanni Paolo Feminis created a perfume water called Aqua Admirabilis, today best known as eau de cologne, while his nephew Johann Maria Farina (Giovanni Maria Farina) in 1732 took over the business. By the 18th century, aromatic plants were being grown in the Grasse region of France, in Sicily, and in Calabria, Italy to provide the growing perfume industry with raw materials. Even today, Italy and France remain the centre of the European perfume design and trade.

Concentration

Perfume types reflect the concentration of aromatic compounds in a solvent, which in fine fragrance is typically ethanol or a mix of water and ethanol. Various sources differ considerably in the definitions of perfume types. The concentration by percent/volume of perfume oil is as follows:

Perfume oils are often diluted with a solvent, though this is not always the case, and its necessity is disputed. By far the most common solvent for perfume oil dilution is ethanol or a mixture of ethanol and water. Perfume oil can also be diluted by means of neutral-smelling oils such as fractionated coconut oil, or liquid waxes such as jojoba oil.

The intensity and longevity of a perfume is based on the concentration, intensity and longevity of the aromatic compounds (natural essential oils / perfume oils) used: As the percentage of aromatic compounds increases, so does the intensity and longevity of the scent created. Different perfumeries or perfume houses assign different amounts of oils to each of their perfumes. Therefore, although the oil concentration of a perfume in Eau de Parfum (EdP) dilution will necessarily be higher than the same perfume in Eau de Toilette (EdT) from within the same range, the actual amounts can vary between perfume houses. An EdT from one house may be stronger than an EdP from another.

Men's fragrances are rarely sold as EdP or perfume extracts; equally so, women's fragrances are rarely sold in EdC concentrations. Although this gender specific naming trend is common for assigning fragrance concentrations, it does not directly have anything to do with whether a fragrance was intended for men or women. Furthermore, some fragrances with the same product name but having a different concentration name may not only differ in their dilutions, but actually use different perfume oil mixtures altogether. For instance, in order to make the EdT version of a fragrance brighter and fresher than its EdP, the EdT oil may be "tweaked" to contain slightly more top notes or fewer base notes. In some cases, words such as "extrême", "intense" or "concentrée", that might indicate aromatic concentration are sometimes completely different fragrances that relate only because of a similar perfume accord. An example of this would be Chanel‘s Pour Monsieur and Pour Monsieur Concentrée.

Eau de Cologne (EdC) since 1706 in Cologne, Germany is originally a specific fragrance and trademark. However outside of Germany the term has become generic for Chypre citrus perfumes (without base-notes).

Describing a perfume

Shelves of perfumes

The precise formulae of commercial perfumes are kept secret. Even if they were widely published, they would be dominated by such complex ingredients and odorants that they would be of little use in providing a guide to the general consumer in description of the experience of a scent. Nonetheless, connoisseurs of perfume can become extremely skillful at identifying components and origins of scents in the same manner as wine experts.[8]

The most practical way to start describing a perfume is according to the elements of the fragrance notes of the scent or the family it belongs to, all of which affect the overall impression of a perfume from first application to the last lingering hint of scent.[9][10]

Fragrance notes

Fragrance pyramid

Perfume is described in a musical metaphor as having three sets of notes, making the harmonious scent accord. The notes unfold over time, with the immediate impression of the top note leading to the deeper middle notes, and the base notes gradually appearing as the final stage. These notes are created carefully with knowledge of the evaporation process of the perfume.

The scents in the top and middle notes are influenced by the base notes, as well the scents of the base notes will be altered by the type of fragrance materials used as middle notes. Manufacturers of perfumes usually publish perfume notes and typically they present it as fragrance pyramid, with the components listed in imaginative and abstract terms.

Olfactive families

Grouping perfumes, like any taxonomy, can never be a completely objective or final process. Many fragrances contain aspects of different families. Even a perfume designated as "single flower", however subtle, will have undertones of other aromatics. "True" unitary scents can rarely be found in perfumes as it requires the perfume to exist only as a singular aromatic material.

Classification by olfactive family is a starting point for a description of a perfume, but it cannot by itself denote the specific characteristic of that perfume.

Traditional

The traditional classification which emerged around 1900 comprised the following categories:

Modern

Since 1945, due to great advances in the technology of perfume creation (i.e., compound design and synthesis) as well as the natural development of styles and tastes; new categories have emerged to describe modern scents:

Fragrance wheel

Fragrance Wheel perfume classification chart, ver. 1983

The Fragrance wheel is a relatively new classification method that is widely used in retail and in the fragrance industry. The method was created in 1983 by Michael Edwards, a consultant in the perfume industry, who designed his own scheme of fragrance classification.The new scheme was created in order to simplify fragrance classification and naming scheme, as well as to show the relationships between each of the individual classes[11].

The five standard families consist of Floral, Oriental, Woody, Fougère, and Fresh, with the former four families being more "classic" while the latter consisting of newer bright and clean smelling citrus and oceanic fragrances that have arrived due to improvements in fragrance technology. Each of the families are in turn divided into sub-groups and arranged around a wheel.

Aromatics sources

Plant sources

Plants have long been used in perfumery as a source of essential oils and aroma compounds. These aromatics are usually secondary metabolites produced by plants as protection against herbivores, infections, as well as to attract pollinators. Plants are by far the largest source of fragrant compounds used in perfumery. The sources of these compounds may be derived from various parts of a plant. A plant can offer more than one source of aromatics, for instance the aerial portions and seeds of coriander have remarkably different odors from each other. Orange leaves, blossoms, and fruit zest are the respective sources of petitgrain, neroli, and orange oils.

Animal sources

Other natural sources

Synthetic sources

Many modern perfumes contain synthesized odorants. Synthetics can provide fragrances which are not found in nature. For instance, Calone, a compound of synthetic origin, imparts a fresh ozonous metallic marine scent that is widely used in contemporary perfumes. Synthetic aromatics are often used as an alternate source of compounds that are not easily obtained from natural sources. For example, linalool and coumarin are both naturally occurring compounds that can be inexpensively synthesized from terpenes. Orchid scents (typically salicylates) are usually not obtained directly from the plant itself but are instead synthetically created to match the fragrant compounds found in various orchids.

The majority of the world's synthetic aromatics are created by relatively few companies. They include:

Each of these companies patents several processes for the production of aromatic synthetics annually.

Characteristics

Natural and synthetics are used for their different odor characteristics in perfumery

Naturals Synthetics
Variance Vary by the times and locations where they are harvested as well as how the product was extracted from the raw material. It's much more difficult to produce consistent products with equivalent odor over years of harvest and production. As such, the perfumer has to "manually" balance-out the natural variations of the ingredients in order to maintain the quality of the perfume. Much more consistent than natural aromatics. However, differences in organic synthesis may result in minute differences in concentration of impurities. If these impurities have low smell (detection) thresholds, the differences in the scent of the synthetic aromatic will be significant.
Components Thousands of chemical compounds; large potential for allergies. Depending on purity, consists primarily of one chemical compound.
Scent Uniqueness Bears a somewhat similar scent to its originating material, depending on the extraction method. Similar to natural scents if the compounds are the same. Novel scent compounds not found in nature will often be unique in their scent and dissimilar to the scents of any naturals.
Scent Complexity Deep and complex fragrance notes. Softer with subtle scent nuances. Pure and pronounced fragrance notes. Structural and defined.
Price Perfume composed of largely natural materials are usually much more expensive. Perfumes using largely synthetic aromatics can be available at widely-affordable prices. Synthetic aromatics are not necessarily cheaper than naturals, with some synthetics being more costly than most natural ingredients due to various factors such as the complexity of synthesis or extraction procedure. However, due to their low odor threshold, one does not need to use much of these materials to produce a perfume.

Obtaining natural odorants

Before perfumes can be composed, the odorants used in various perfume compositions must first be obtained. Synthetic odorants are produced through organic synthesis and purified. Odorants from natural sources require the use of various methods to extract the aromatics from the raw materials. The results of the extraction are either essential oils, absolutes, concretes, or butters, depending on the amount of waxes in the extracted product.[14]

All these techniques will, to a certain extent, distort the odor of the aromatic compounds obtained from the raw materials. This is due to the use of heat, harsh solvents, or through exposure to oxygen in the extraction process which will denature the aromatic compounds, which either change their odor character or renders them odorless.

Fragrant extracts

Although fragrant extracts are known to the general public as the generic term "essential oils", a more specific language is used in the fragrance industry to describe the source, purity, and technique used to obtain a particular fragrant extract.

Of these extracts, only absolutes, essential oils, and tinctures are directly used to formulate perfumes.

Products from different extraction methods are known under different names even though their starting materials are the same. For instance, orange blossoms from Citrus aurantium that have undergone solvent extraction produces "orange blossom absolute" but that which have been steam distilled is known as "neroli oil".

Composing perfumes

Perfume compositions are an important part of many industries ranging from the luxury goods sectors, food services industries, to manufacturers of various household chemicals. The purpose of using perfume or fragrance compositions in these industries is to affect customers through their sense of smell and entice them into purchasing the perfume or perfumed product. As such there is significant interest in producing a perfume formulation that people will find aesthetically pleasing.

The perfumer

The job of composing perfumes that will sell is left up to an expert on perfume composition or known in the fragrance industry as the perfumer. They are also sometimes referred to affectionately as a "Nez" (French for nose) due to their fine sense of smell and skill in smell composition.

The composition of a perfume typically begins with a brief by the perfumer's employer or an outside customer. The customers to the perfumer or their employers, are typically fashion houses or large corporations of various industries. The perfumer will then go through the process of blending multiple perfume mixtures and sell the formulation to the customer, often with modifications of the composition of the perfume.

The perfume composition will then be either used to enhance another product as a functional fragrance (shampoos, make-up, detergents, car interiors, etc.), or marketed and sold directly to the public as a fine fragrance.[8]

Technique

Paper blotters are commonly used by perfumers to sample and smell perfumes and odorants.

Although there is no single "correct" technique for the formulation of a perfume, there are general guidelines as to how a perfume can be constructed from a concept. Although many ingredients do not contribute to the smell of a perfume, many perfumes include colorants and anti-oxidants to improve the marketability and shelf life of the perfume, respectively.

Basic framework

Perfume oils usually contain tens to hundreds of ingredients and these are typically organized in a perfume for the specific role they will play. These ingredients can be roughly grouped into four groups:

The top, middle, and base notes of a fragrance may have separate primary scents and supporting ingredients. The perfume's fragrance oils are then blended with ethyl alcohol and water, aged in tanks for several weeks and filtered through processing equipment to, respectively allow the perfume ingredients in the mixture to stabilize and to remove any sediment and particles before the solution can be filled into the perfume bottles[15].

Fragrance bases

Instead of building a perfume from "ground up", many modern perfumes and colognes are made using fragrance bases or simply bases. Each base is essentially modular perfume that is blended from essential oils and aromatic chemicals, and formulated with a simple concept such as "fresh cut grass" or "juicy sour apple". Many of Guerlain's Aqua Allegoria line, with their simple fragrance concepts, are good examples of what perfume fragrance bases are like.

The effort used in developing bases by fragrance companies or individual perfumers may equal that of a marketed perfume, since they are useful in that they are reusable. On top of its reusability, the benefit in using bases for construction are quite numerous:

  1. Ingredients with "difficult" or "overpowering" scents that are tailored into a blended base may be more easily incorporated into a work of perfume
  2. A base may be better scent approximations of a certain thing than the extract of the thing itself. For example, a base made to embody the scent for "fresh dewy rose" might be a better approximation for the scent concept of a rose after rain than plain rose oil. Flowers whose scents cannot be extracted, such as gardenia or hyacinth, are composed as bases from data derived from headspace technology.
  3. A perfumer can quickly rough out a concept from a brief by cobbling together multiple bases, then present it for feedback. Smoothing out the "edges" of the perfume can be done after a positive response.

Reverse engineering

Creating perfumes through reverse engineering with analytical techniques such as GC/MS can reveal the "general" formula for any particular perfume. The difficulty of GC/MS analysis arises due to the complexity of a perfume's ingredients. This is particularly due to the presence of natural essential oils and other ingredients consisting of complex chemical mixtures. However, "anyone armed with good GC/MS equipment and experienced in using this equipment can today, within days, find out a great deal about the formulation of any perfume... customers and competitors can analyze most perfumes more or less precisely."[16]

Antique or badly preserved perfumes undergoing this analysis can also be difficult due to the numerous degradation by-products and impurities that may have resulted from breakdown of the odorous compounds. Ingredients and compounds can usually be ruled out or identified using gas chromatograph (GC) smellers, which allow individual chemical components to be identified both through their physical properties and their scent. Reverse engineering of best-selling perfumes in the market is a very common practice in the fragrance industry due to the relative simplicity of operating GC equipment, the pressure to produce marketable fragrances, and the highly lucrative nature of the perfume market.[15]

Health and environmental issues

Perfume ingredients, regardless of natural or synthetic origins, may all cause health or environmental problems when used or abused in substantial quantities. Although the areas are under active research, much remains to be learned about the effects of fragrance on human health and the environment.

Health

Immunological

Evidence in peer-reviewed journals shows that some fragrances can cause asthmatic reactions in some individuals, especially those with severe or atopic asthma[17]. Many fragrance ingredients can also cause headaches, allergic skin reactions[18] or nausea.[19][20][21]

In some cases, an excessive use of perfumes may cause allergic reactions of the skin. For instance, acetophenone, ethyl acetate and acetone[15] while present in many perfumes, are also known or potential respiratory allergens. Nevertheless this may be misleading, since the harm presented by many of these chemicals (either natural or synthetic) is dependent on environmental conditions and their concentrations in a perfume. For instance, linalool, which is listed as an irritant, causes skin irritation when it degrades to peroxides, however the use of antioxidants in perfumes or reduction in concentrations can prevent this.

Some research on natural aromatics have shown that many contain compounds that cause skin irritation[22]. However some studies, such as IFRA's research claim that opoponax is too dangerous to be used in perfumery, still lack scientific consensus [23]. It is also true that sometimes inhalation alone can cause skin irritation.

Carcinogenicity

There is scientific evidence that some common ingredients, like certain polycyclic synthetic musks, can disrupt the balance of hormones in the human body (endocrine disruption)[24] [25] and even cause cancer (nitro-musks). Some natural aromatics, such as oakmoss absolutes, contain allergens and carcinogenic compounds [22][26].

Environmental

Pollution

Synthetic musks are pleasant in smell and relatively inexpensive, as such they are often employed in large quantities to cover the unpleasant scent of laundry detergents and many personal cleaning products. Due to their large scale use, several types of synthetic musks have been found in human fat and milk[27], as well as in the sediments and waters of the Great Lakes [28]

These pollutants may pose additional health and environmental problems when they enter human and animal diets.

Species endangerment

The demands for aromatic materials like sandalwood, agarwood, musk has led to the endangerment of these species as well as illegal trafficking and harvesting.

Safety regulation

The perfume industry in the US is not directly regulated by the FDA, instead the FDA controls the safety of perfumes through their ingredients and require that they be tested to the extent that they are Generally recognized as safe (GRAS). Due to the need for protection of trade secrets, companies rarely give the full listing of ingredients regardless of their effects on health. In Europe, as from 11 March 2005, the mandatory listing of a set of 26 recognized fragrance allergens was enforced.[29] The requirement to list these materials is dependant on the intended use of the final product. The limits above which the allegens are required to be declared are 0.001% for products intended to remain on the skin,and 0.01% for those intended to be rinsed off. This has resulted in many old perfumes like chypres and fougère classes, which require the use of oakmoss extract, being reformulated.

Preserving perfume

Fragrance compounds in perfumes will degrade or break down if improperly stored in the presence of:

Proper preservation of perfumes involve keeping them away from sources of heat and storing them where they will not be exposed to light. An opened bottle will keep its aroma intact for several years, as long as it is well stored.[8] However the presence of oxygen in the head space of the bottle and environmental factors will in the long run alter the smell of the fragrance.

Perfumes are best preserved when kept in light-tight aluminium bottles or in their original packaging when not in use, and refrigerated to relatively low temperatures: between 3-7 degrees Celsius (37-45 degrees Fahrenheit). Although it is difficult to completely remove oxygen from the headspace of a stored flask of fragrance, opting for spray dispensers instead of rollers and "open" bottles will minimize oxygen exposure. Sprays also have the advantage of isolating fragrance inside a bottle and preventing it from mixing with dust, skin, and detritus, which would degrade and alter the quality of a perfume.

Lists of perfumes

See also

References

  1. ↑ http://www.merriam-webster.com/dictionary/perfume
  2. ↑ Strathern, Paul (2000). Mendeleyev's Dream - The Quest For the Elements. New York: Berkley Books. ISBN 0425184676. 
  3. ↑ Levey, Martin (1973). Early Arabic Pharmacology: An Introduction Based on Ancient and Medievl Sources. Brill Archive. pp. 9. ISBN 9004037969. 
  4. ↑ http://archaeologynews.multiply.com/journal/item/309
  5. ↑ 4,000-Year-Old Perfumes Found
  6. ↑ Fox News: Ancient Perfumes Recreated, Put on Display in Rome
  7. ↑ al-Hassani, Woodcok and Saoud (2006) 1001 Inventions; Muslim Heritage in Our World, FSTC, p.22.
  8. ↑ 8.0 8.1 8.2 Burr, Chandler (2003). The Emperor of Scent: A Story of Perfume, Obsession, and the Last Mystery of the Senses. New York: Random House. ISBN 0-375-50797-3. 
  9. ↑ 9.0 9.1 9.2 Perfume connoisseurs speak of a fragrance's "sillage", or the discernible trail it leaves in the air when applied. Fortineau, Anne-Dominique (2004). "Chemistry Perfumes Your Daily Life". Journal of Chemical Education.81(1)
  10. ↑ Edwards, Michael (2006). "Fragrances of the World 2006". Crescent House Publishing. ISBN 0-9756097-1-8
  11. ↑ Osborne, Grant (2001-05-01). "Interview with Michael Edwards". Basenotes. http://www.basenotes.net/interviews/int-medwards.html. Retrieved 2006-12-17. 
  12. ↑ zibetto, civet, civette, profumi animali, aromaterapia, feromoni, pheromons, animal, scents, perfumes,parfums animaux
  13. ↑ http://aftelier.com/store/index.php?main_page=product_info&cPath=5_8&products_id=52
  14. ↑ Camps, Arcadi Boix (2000). "Perfumery Techniques in Evolution". Allured Pub Corp. ISBN 0-931710-72-3
  15. ↑ 15.0 15.1 15.2 Burr, Chandler (2008). The Perfect Scent: A Year Inside the Perfume Industry in Paris & New York. Henry Holt and Co.. ISBN 978-0805080377. 
  16. ↑ Calkin, Robert R. & Jellinek, J. Stephen (1994). "Perfumery: practice and principles". John Wiley & Sons, Inc.. ISBN 0-471-58934-9
  17. ↑ Kumar P, Caradonna-Graham VM, Gupta S, Cai X, Rao PN, Thompson J (November 1995). "Inhalation challenge effects of perfume scent strips in patients with asthma". Ann. Allergy Asthma Immunol. 75 (5): 429–33. PMID 7583865. 
  18. ↑ Frosch PJ, Rastogi SC, Pirker C, et al. (April 2005). "Patch testing with a new fragrance mix - reactivity to the individual constituents and chemical detection in relevant cosmetic products". Contact Derm. 52 (4): 216–25. doi:10.1111/j.0105-1873.2005.00563.x. PMID 15859994. 
  19. ↑ Deborah Gushman. "The Nose Knows". http://www.hanahou.com/pages/magazine.asp?Action=DrawArticle&ArticleID=373&MagazineID=23. Retrieved 2008-05-07. 
  20. ↑ Apostolidis S, Chandra T, Demirhan I, Cinatl J, Doerr HW, Chandra A (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. PMID 12529978. 
  21. ↑ Schmeiser HH, Gminski R, Mersch-Sundermann V (May 2001). "Evaluation of health risks caused by musk ketone". Int J Hyg Environ Health 203 (4): 293–9. doi:10.1078/1438-4639-00047. PMID 11434209. 
  22. ↑ 22.0 22.1 Environmental and Health Assessment of Substances in Household Detergents and Cosmetic Detergent Products [1]
  23. ↑ http://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_025b.pdf
  24. ↑ Schreurs RH, Legler J, Artola-Garicano E, et al. (February 2004). "In vitro and in vivo antiestrogenic effects of polycyclic musks in zebrafish". Environ. Sci. Technol. 38 (4): 997–1002. doi:10.1021/es034648y. PMID 14998010. 
  25. ↑ Schreurs RH, Sonneveld E, Jansen JH, Seinen W, van der Burg B (February 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. doi:10.1093/toxsci/kfi035. PMID 15537743. 
  26. ↑ Rastogi SC, Bossi R, Johansen JD, et al. (June 2004). "Content of oak moss allergens atranol and chloroatranol in perfumes and similar products". Contact Derm. 50 (6): 367–70. doi:10.1111/j.0105-1873.2004.00379.x. PMID 15274728. 
  27. ↑ Duedahl-Olesen L, Cederberg T, Pedersen KH, Højgård A (October 2005). "Synthetic musk fragrances in trout from Danish fish farms and human milk". Chemosphere 61 (3): 422–31. doi:10.1016/j.chemosphere.2005.02.004. PMID 16182860. 
  28. ↑ Peck AM, Linebaugh EK, Hornbuckle KC (September 2006). "Synthetic musk fragrances in Lake Erie and Lake Ontario sediment cores". Environ. Sci. Technol. 40 (18): 5629–35. doi:10.1021/es060134y. PMID 17007119. 
  29. ↑ http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2003:066:0026:0035:EN:PDF "DIRECTIVE 2003/15/EC"

Further reading

External links