Aroma chemicals, fragrance oils in cosmetics

Most people enjoy products with a pleasant scent, and personal care items are no exception. However, all of the guide formulations on this website are deliberately fragrance free. The reason is simple: perfumes are complex, costly, and scent perception is highly personal and often influenced by individual preference and even gender.

As an interesting aside about aroma chemicals, at low concentrations indole and its close chemical relative skatole can smell surprisingly floral, reminiscent of jasmine, neroli, or orange blossom. At high concentrations, however, both have an extremely unpleasant odor, and skatole is one of the compounds responsible for the smell of mammalian feces. In theory, simply diluting them could transform an offensive odor into something beautifully floral.

Last but not least, pleasant-smelling chemicals or natural ingredients may seem harmless, but they can pose risks when used above safe concentration levels in both rinse-off and leave-on products. Formulation is complex, and many fragrance ingredients are strictly regulated due to their potential to cause allergic reactions. Despite this, they are still commonly found in cosmetics. Check the ingredient list on your shampoo, cream, or lotion etc—chances are, you’ll spot at least one of the substances listed below if they are in the following concentration range:

• > 0,001% in leave-on products
• > 0,01% in rinse-off products

Fragrance allergens:

alpha-isomethyl ionone
Amyl cinnamal
Amylcinnamyl alcohol
Anisyl alcohol
Benzyl alcohol
Benzyl benzoate
Benzyl cinnamate
Benzyl salicylate
Cinnamal
Cinnamyl alcohol
Citral
Citronellol
Coumarin
d-Limonene
Eugenol
Farnesol
Geraniol
Hexyl cinnamaldehyde
Hydroxycitronellal
Isoeugenol
Lilial (banned in EU)
Linalool
Lyral (banned in EU)
Methyl heptin carbonate
Oak moss and treemoss extract
Treemoss extract

Recently, the list has been expanded (we are still in the transition time) from 26 to 82 ingredient and some natural oils are no exception either. The newly added materials are:

3-Propylidenephthalide
6-Methyl Coumarin
Acetyl Cedrene
Alpha-Terpinene
Amyl Salicylate
Anethole
Benzaldehyde
Betacaryophyllene
Camphor
Cananga Odorata Oil/Extract
Carvone
Cedrus Atlantica Oil/ Extract
Cinnamomum Cassia Leaf Oil
Cinnamomum Zeylanicum Bark Oil
Citrus Aurantium Bergamia Peel Oil
Citrus Aurantium Flower Oil
Citrus Aurantium Peel Oil
Citrus Limon Peel Oil
Dimethyl Phenethyl Acetate
Eucalyptus Globulus Oil
Eugenia Caryophyllus Oil
Eugenyl Acetate
Geranyl Acetate
Hexadecanolac Tone
Hexamethylinda Nopyran
Isoeugenyl Acetate
Jasmine Oil/Extract
Juniperus Virginiana Oil
Laurus Nobilis Leaf Oil
Lavandula Oil/ Extract
Lemongrass Oil
Linalyl Acetate
Lippia Citriodora Absolute
Mentha Piperita Oil
Mentha Viridis Leaf Oil
Menthol
Methyl Salicylate
Myroxylon Pereirae Oil/Extract
Narcissus Extract
Pelargonium Graveolens Flower Oil
Pinene
Pinus Mugo
Pinus Pumila
Pogostemon Cablin Oil
Rose Flower Oil/Extract
Rose Ketones
Salicylaldehyde
Santalol
Santalum Album Oil
Sclareol
Terpineol
Terpinolene
Tetramethyl Acetyloctahydronaphthalenes
Trimethylbenzenepropanol
Trimethylcyclopentenyl Methylisopentenol
Turpentine
Vanillin