FRAGRANCE IN SKIN CARE
Fragrance is a vague term included in many skin care ingredient lists but what does it mean and why should we be concerned? Let’s unpack some of the common “fragrance” molecules and learn how to better navigate ingredient lists and informational resources.
WHAT IS FRAGRANCE?
Under the Fair Packaging and Labeling Act of 1967, all consumables must show a full ingredients list with the exception of any patented trade secrets. Becausefragrances are important for brand identity, theyare often patented so blends of tens or hundreds of molecules can be wrapped up in the ingredient “fragrance” or “parfum” [1]. It can often beimpossible to decipher which fragrance ingredients are in a product.
Molecules that impart scent are very small (<300 Da) volatile molecules that evaporate easily and diffuse through the air. Humans have ~400 olfactory (scent) receptors with ranging affinities for different volatile scent molecules [2]. The combination of scent molecules in a source and the varying receptors they activate leads to our ability to identify tens of thousands of unique smells [3,4]. So what does this have to do with our skin?
HOW DOES FRAGRANCE INTERACT WITH THE SKIN?
Fragrance is considered a sensitizer, similar to sun exposure or air pollution in its ability to make the skin more vulnerable to oxidative damage. In fact,fragrance molecules themselves are often responsible for oxidative damage as they react easily with the skin, air, and other ingredients in a mixture [5]. This is the definition of volatile!These reactions often release reactive oxygen species that can harm the skin. In an allergen patch test on over 4,000 participants, afragrance mixture containing common fragrance ingredients was the 3rd most common cause of dermatitis (skin irritation) [6]. Additionally, in a 21-year retrospective study, approximately 10% of participants reacted to fragrance mixtures [7]. Keep in mind that these mixtures contain fragrance compounds suspected of being irritants. Larger analyses report a number between 2-4% however there are over 160 known allergens and research has not been done of all of them [5].
MINIMIZING YOUR RISK
The truth is that not all fragrance molecules are irritants but because of the FDAloophole, it’s extremely difficultfor the consumer to do research and make an informed decision. The best approach to avoid irritation from fragranceis to research the brand stance on fragrance, buy from brands whose values align with your skin care needs, and patch test new products. Additionally,www.EWG.org can always help you evaluate ingredients that are listed and theInternational Fragrance Association (IFRA) has a Transparency List cataloguing all known fragrance ingredients for cross referencing.
Sources:
1. Nutrition C for FS and A (2020) Fragrances in Cosmetics.FDA.
2. Spehr M, Munger SD (2009) Olfactory receptors: GPCRs and beyond.J Neurochem 109, 1570–1583.
3. Mombaerts P (2004) Genes and ligands for odorant, vomeronasal and taste receptors.Nature Reviews Neuroscience 5, 263–278.
4. Genva M, Kenne Kemene T, Deleu M, Lins L, Fauconnier M-L (2019) Is It Possible to Predict the Odor of a Molecule on the Basis of its Structure?Int J Mol Sci 20,.
5. Groot D, C A (2020) Fragrances: Contact Allergy and Other Adverse Effects.Dermatitis 31, 13–35.
6. Zug K, Warshaw E, Fowler J, Maibach H, Belsito D, Pratt M, Sasseville D, Storrs F, Taylor J, Mathias T, DeLeo V, Rietschel R (2009) Patch-Test Results of the North American Contact Dermatitis Group 2005-2006.Dermatitis 20, 149–160.
7. Nardelli A, Carbonez A, Drieghe J, Goossens A (2013) Results of patch testing with fragrance mix 1, fragrance mix 2, and their ingredients, and Myroxylon pereirae and colophonium, over a 21-year period.Contact Dermatitis 68, 307–313.