Allergens in essential oils

Essential oils can contain several compounds that are known allergens, which may trigger skin irritation, respiratory reactions, or other sensitivities, especially in people with allergies or sensitive skin. The main allergens are usually naturally occurring components of the oils themselves. Some of the most common ones include:

  • Limonene
    Found in: Citrus oils (orange, lemon, lime, bergamot)
    Can oxidize when exposed to air, making it more likely to cause allergic reactions.
  • Linalool
    Found in: Lavender, coriander, basil, and some citrus oils
    Oxidizes in air and may trigger skin sensitization.
  • Geraniol
    Found in: Rose, citronella, palmarosa, geranium oils
    Can cause contact dermatitis in sensitive individuals.
  • Eugenol
    Found in: Clove, cinnamon, basil, nutmeg
    Known for strong sensitizing properties; can trigger skin irritation.
  • Citral
    Found in: Lemongrass, lemon, lime, orange, verbena
    A potent allergen causing contact dermatitis in some cases.
  • Cinnamaldehyde
    Found in: Cinnamon leaf and bark oils
    Highly allergenic and a strong skin irritant.
  • Isoeugenol
    Found in: Ylang-ylang, basil, and some essential oil blends
    Can trigger skin reactions; considered a fragrance allergen in cosmetics.
  • Benzyl Alcohol / Benzyl Benzoate / Benzyl Salicylate
    Found in: Jasmine, ylang-ylang, and other floral oils
    Used in perfumes and can be allergenic.
  • Farnesol
    Found in: Jasmine, lemongrass, rose oils
    Known contact allergen in fragrance mixtures.

Key Notes:
Oxidation risk: Many terpenes like limonene and linalool become more allergenic once oxidized.
Photo-sensitivity: Some citrus oils (bergamot, lemon) can make skin sensitive to sunlight.

The following are some common essential oils and their main allergenic compounds:

  • Lavender
    Linalool, Limonene
    Oxidation increases allergenicity; mild but possible skin reactions
  • Tea Tree
    Linalool, Terpinen-4-ol
    Can cause contact dermatitis in sensitive individuals
  • Lemon / Lime / Bergamot
    Linalool, Citral, Bergapten (bergamot)
    Photo-sensitizing (especially bergamot); oxidizes easily.
  • Orange / Sweet Orange
    Limonene, Linalool
    Generally mild, but oxidized oil is more allergenic.
  • Rose / Geranium
    Geraniol, Citronellol, Linalool, Farnesol
    Strong fragrance allergens; can trigger dermatitis.
  • Ylang-Ylang
    Linalool, Benzyl Benzoate, Isoeugenol, Farnesol
    Highly allergenic floral scent; caution in sensitive skin.
  • Clove
    Eugenol, Caryophyllene
    Strong sensitizer; may irritate skin.
  • Cinnamon (Leaf & Bark)
    Cinnamaldehyde, Eugenol
    Highly allergenic; strong irritant.
  • Basil
    Linalool, Eugenol, Isoeugenol
    Possible skin sensitization.
  • Lemongrass
    Citral, Geraniol, Farnesol
    Can irritate skin; photo-sensitivity risk.
  • Jasmine
    Benzyl Alcohol, Benzyl Benzoate, Farnesol
    Common fragrance allergens.
  • Nutmeg
    Eugenol, Myristicin
    Irritant at high concentrations.
  • Peppermint
    Limonene, Menthol
    Mild allergen; may cause skin irritation if concentrated.

European regulations

EU Regulation 2023/1545, which amends EC Regulation 1223/2009 regarding fragrance allergens in cosmetic products, adds 56 fragrance allergens to the original list of 26, bringing the total to 82.

The original 26 allergens:

Chemical nameName of Common Ingredients GlossaryCAS number
2-BenzylideneheptanalAmyl cinnamal122-40-7
Benzyl alcoholBenzyl alcohol100-51-6
Cinnamyl alcoholCinnamyl alcohol104-54-1
3,7-Dimethyl-2,6- octadienalCitral5392-40-5
Phenol, 2-methoxy- 4-(2-propenyl)Eugenol97-53-0
7-HydroxycitronellalHydroxy-citronellal107-75-5
Phenol, 2-methoxy-4- (1-propenyl)-Isoeugenol97-54-1
2-Pentyl- 3-phenylprop-2-en-1-olAmylcin-namyl alcohol101-85-9
Benzyl salicylateBenzyl salicylate118-58-1
2-Propenal, 3-phenyl-Cinnamal104-55-2
2H-1-Benzopyran- 2-oneCoumarin91-64-5
2,6-Octadien-1-ol, 3,7-dimethyl-, (2E)-Geraniol106-24-1
3 and 4-(4-Hydroxy- 4-methylpentyl) cyclohex-3-ene-1- carbaldehydeHydroxyisohexyl 3-cyclohexene carbox­ aldehyde31906-04-4
4-Methoxybenzyl alcoholAnisyl alcohol105-13-5
2-Propenoic acid, 3-phenyl-, phenylm­ethyl esterBenzyl cinnamate103-41-3
2,6,10-Dodecatrien-1- ol, 3,7,11-trimethyl-Farnesol4602-84-0
2-(4-tert-Butylbenzyl) propionaldehyde2-(4-tert-Butylbenzyl) propionaldehyde80-54-6
1,6-Octadien-3-ol, 3,7-dimethyl-Linalool78-70-6
Benzyl benzoateBenzyl benzoate120-51-4
Citronellol/(±) -3,7-dimethyloct-6-en-1-olCitronellol106-22-9
2-BenzylideneoctanalHexyl cinnamaldehyde101-86-0
(4R)-1-Methyl-4-(1- methylethenyl) cyclo­hexened-Limonene5989-27-5
Methyl heptin carbonateMethyl 2-octynoate111-12-6
3-Methyl-4-(2,6,6-tri-methyl-2-cyclohexen-1-yl)-3-buten-2-onealpha-Isomethyl ion­one127-51-5
Oak moss extractEvernia prunastri extract90028-68-55
Treemoss extractEvernia furfuracea extract90028-67-4

The 56 added allergens:

Chemical nameName of Common Ingredients GlossaryCAS number
Benzyl alcoholBenzyl Alcohol100-51-6
6-Methylcoumarin6-Methyl Coumarin92-48-8
3,7-Dimethyl-2,6-octadienalCitral5392-40-5
(E)-3,7-dimethylocta-2,6-dienalGeranial141-27-5
(Z)-3,7-dimethylocta-2,6-dienalNeral106-26-3
Phenol, 2-methoxy-4-(1-propenyl)Isoeugenol97-54-1
(E)-2-methoxy-4-(prop-1-enyl)phenol; (trans-Isoeugenol)Isoeugenol5932-68-3
(Z)-2-methoxy-4-(prop-1-enyl)phenol; (cis-Isoeugenol)Isoeugenol5912-86-7
Citronellol/ (±)3,7-Dimethyl-6-octen-1-olCitronellol106-22-9 26489-01-0
(3R)-3,7-dimethyloct-6-en-1-olCitronellol1117-61-9
(3S)-3,7-dimethyloct-6-en-1-olCitronellol7540-51-4
1-methyl-4-prop-1-en-2-yl-cyclohexene; dl-limonene (racemic); DipenteneLimonene138-86-37705-14-8
(R)-p-mentha-1,8-diene; (d-limonene)Limonene5989-27-5
(S)-p-mentha-1,8-diene; (l-limonene)Limonene5989-54-8
Pinus mugo leaf and twig oil and extractPinus Mugo Leaf Oil; Pinus Mugo Twig Leaf Extract; Pinus Mugo Twig Oil90082-72-7
Pinus pumila leaf and twig oil and extractPinus Pumila Needle Extract; Pinus Pumila Twig Leaf Extract; Pinus Pumila Twig Leaf Oil97676-05-6
Cedrus atlantica oil and extractCedrus Atlantica Bark Extract; Cedrus Atlantica Bark Oil; Cedrus Atlantica Bark Water; Cedrus Atlantica Leaf Extract; Cedrus Atlantica Wood Extract; Cedrus Atlantica Wood Oil92201-55-3 8023-85-6
Turpentine gum (Pinus spp.); Turpentine oil and rectified oil; Turpentine, steam distilled (Pinus spp.)Turpentine9005-90-7 8006-64-2 8052-14-0
p-Mentha-1,3-dieneAlpha-Terpinene99-86-5
p-Mentha-1,4(8)-dieneTerpinolene586-62-9
Myroxylon balsamum var. pereirae; extracts and distillates; Balsam Peru oil, absolute and anhydrol (Balsam Oil Peru)Myroxylon Balsamum Pereirae Balsam Extract; Myroxylon Balsamum Pereirae Balsam Oil; Myroxylon Pereirae Oil; Myroxylon Pereirae Resin Extract; Myroxylon Pereirae Resin8007-00-9
1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-buten-1-oneAlpha-Damascone; cis-Rose ketone 143052-87-5 23726-94-5
1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-buten-1-onetrans-Rose ketone 124720-09-0
1-(2,6,6-Trimethylcyclohexa-1,3-dien-1-yl)-2-buten-1-oneRose ketone 4 (Damascone)23696-85-7
1-(2,6,6-Trimethyl-3-cyclohexen-1-yl)-2-buten-1-oneRose ketone 3 (delta-Damascone)57378-68-4
1-(2,6,6-Trimethyl-3-cyclohexen-1-yl)-2-buten-1-onetrans-Rose ketone 371048-82-3
(Z)-1-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-buten-1-onecis-Rose ketone 2 (cis-beta-Damascone)23726-92-3
(E)-1-(2,6,6-Trimethyl-1-cyclohexen-1-yl)-2-buten-1-onetrans-Rose ketone 2 (trans-beta-Damascone)23726-91-2
3-Propylidene-1(3H)-isobenzofuranone;3-Propylidenephthalide3-Propylidenephthalide17369-59-4
Verbena absoluteLippia citriodora absolute8024-12-2 85116-63-8
Methyl 2-hydroxybenzoateMethyl Salicylate119-36-8
3R-(3α,3aβ,7β,8aα)]-1-(2,3,4,7,8,8a-hexahydro-3,6,8,8-tetramethyl-1H-3a,7-methanoazulen-5-yl)ethan-1-oneAcetyl Cedrene32388-55-9
Pentyl-2-hydroxy-benzoateAmyl Salicylate2050-08-0
1-Methoxy-4-(1E)-1-propen-1-yl-benzene (trans-Anethole)Anethole104-46-14180-23-8
BenzaldehydeBenzaldehyde100-52-7
Bornan-2-one; 1,7,7-Trimethylbi-cyclo[2.2.1]-2-heptanoneCamphor76-22-221368-68-3464-49-3464-48-2
(1R,4E,9S)-4,11,11-Trimethyl-8-methylenebicyclo[7.2.0]undec-4-eneBeta-Caryophyllene87-44-5
2-methyl-5-(prop-1-en-2-yl)cyclohex-2-en-1-one;(5R)-2-Methyl-5-prop-1-en-2-ylcyclohex-2-en-1-one;(5S)-2-Methyl-5-prop-1-en-2-ylcyclohex-2-en-1-oneCarvone99-49-06485-40-1 2244-16-8
2-Methyl-1-phenyl-2-propyl acetate; Dimethylbenzyl Carbinyl AcetateDimethyl Phenethyl Acetate151-05-3
Oxacyclohepta-decan-2-oneHexadecanolactone109-29-5
1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-γ-2-benzopyranHexamethylindanopyran1222-05-5
3,7-Dimethyl octa-1,6-diene-3-yl acetateLinalyl Acetate115-95-7
Menthol;dl-menthol;l-menthol;d-mentholMenthol89-78-11490-04-6 2216-51-5 15356-60-2
3-Methyl-5-(2,2,3-Trimethyl-3-Cyclopentenyl)pent-4-en-2-olTrimethylcyclopentenyl Methylisopentenol67801-20-1
o-Hydroxy-benzaldehydeSalicylaldehyde90-02-8
5-(2,3-Dimethyl-tricyclo[2.2.1.02,6]-hept-3-yl)-2-methylpent-2-en-1-ol (alpha-Santalol);(1S-(1a,2a(Z),4a))-2-Methyl-5-(2-methyl-3-methylenebicyclo[2.2.1]hept-2-yl)-2-penten-1-ol(beta-Santalol)Santalol11031-45-1115-71-977-42-9
[1R-(1alpha)]-alpha-Ethenyldecahydro-2-hydroxy-a,2,5,5,8a-pentamethyl-1-naphthalenepropanolSclareol515-03-7
2-(4-methylcyclohex-3-en-1-yl)propan-2-ol; p-Menth-1-en-8-ol (alpha-Terpineol); 1-methyl-4-(1-methylvinyl)cyclohexan-1-ol (beta-Terpineol); 1-methyl-4-(1-methylethylidene)cyclohexan-1-ol (gamma-Terpineol)Terpineol8000-41-798-55-5138-87-4586-81-2
1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one; 1-(1,2,3,4,5,6,7,8-octahydro-2,3,5,5-tetramethyl-2-naphthyl)ethan-1-one; 1-(1,2,3,5,6,7,8,8a-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one; 1-(1,2,3,4,6,7,8,8a-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-oneTetramethyl acetyloctahydronaphthalenes54464-57-254464-59-468155-66-868155-67-9
3-(2,2-Dimethyl-3-hydroxypropyl)tolueneTrimethylbenzenepropanol103694-68-4
4-Hydroxy-3-methoxybenz-aldehydeVanillin121-33-5
Cananga odorata flower oil and extract; Ylang Ylang flower oil and extractCananga Odorata Flower Extract; Cananga Odorata Flower Oil83863-30-38006-81-368606-83-793686-30-7
Cinnamomum cassia leaf OilCinnamomum Cassia Leaf Oil8007-80-584961-46-6
Cinnamomum zeylanicum bark oilCinnamomum Zeylanicum Bark Oil8015-91-684649-98-9
Citrus aurantium amara and dulcis peel oilCitrus Aurantium Amara Flower Oil72968-50-4
Citrus aurantium amara and dulcis flower oilCitrus Aurantium Dulcis Flower Oil8028-48-68016-38-4
Citrus aurantium amara and dulcis peel oilCitrus Aurantium Amara Peel Oil68916-04-172968-50-4
Citrus aurantium amara and dulcis peel oilCitrus Aurantium Dulcis Peel Oil;97766-30-88028-48-6
Citrus aurantium amara and dulcis peel oilCitrus Sinensis Peel Oil8008-57-9
Citrus aurantium bergamia oil (Bergamot oil)Citrus Aurantium Bergamia Peel Oil8007-75-889957-91-568648-33-98007-75-885049-52-1
Citrus limon oilCitrus Limon Peel Oil84929-31-78008-56-8
Cymbopogon citratus / schoenanthus/flexuosus oilsCymbopogon Schoenanthus Oil8007-02-189998-16-3
Cymbopogon citratus / schoenanthus/flexuosus oilsCymbopogon Flexuosus Oil91844-92-7
Cymbopogon citratus / schoenanthus/flexuosus oilsCymbopogon Citratus Leaf Oil8007-02-191844-92-7
Eucalyptus globulus oilEucalyptus Globulus Leaf Oil;97926-40-48000-48-4
Eucalyptus globulus oilEucalyptus Globulus Leaf/ Twig Oil8000-48-4
Eugenia caryophyllus oilEugenia Caryophyllus Leaf Oil8000-34-8 8015-97-284961-50-2
Eugenia caryophyllus oilEugenia Caryophyllus Flower Oil84961-50-2
Eugenia caryophyllus oilEugenia Caryophyllus Stem oil84961-50-2
Eugenia caryophyllus oilEugenia Caryophyllus Bud oil84961-50-2
Jasminum grandiflorum/officinale oil and extractJasminum Grandiflorum Flower Extract;84776-64-7
Jasminum grandiflorum/officinale oil and extractJasminum Officinale Oil;90045-94-6 8022-96-6 8024-43-9
Jasminum grandiflorum/officinale oil and extractJasminum Officinale Flower Extract90045-94-6
Juniperus virginiana oilJuniperus Virginiana Oil; Juniperus Virginiana Wood Oil8000-27-9 85085-41-2
Laurus nobilis oilLaurus Nobilis Leaf Oil8002-41-38007-48-584603-73-6
Lavandula hybrida oil/extract;Lavandula Hybrida Oil;91722-69-9
Lavandula hybrida oil/extract;Lavandula Hybrida Extract;8022-15-9
Lavandula hybrida oil/extract;Lavandula Hybrida Flower Extract;93455-96-093455-97-192623-76-2
Lavandula intermedia oil/extract;Lavandula Intermedia Flower Leaf/Stem Extract; Lavandula Intermedia Flower/Leaf/Stem Oil; Lavandula Intermedia Oil84776-65-88000-28-090063-37-9
Lavandula angustifolia oil/extractLavandula Angustifolia Oil; Lavandula Angustifolia Flower/Leaf/Stem Extract84776-65-88000-28-090063-37-9
Mentha piperita oilMentha Piperita Oil8006-90-484082-70-2
Mentha spicata oil (spearmint oil)Mentha Viridis Leaf Oil8008-79-584696-51-5
Narcissus poeticus/pseudonarcissus/jonquilla/tazetta extractNarcissus Poeticus Extract90064-26-968917-12-4
Narcissus poeticus/pseudonarcissus/jonquilla/tazetta extractNarcissus Pseudonarcissus Flower Extract90064-27-0
Narcissus poeticus/pseudonarcissus/jonquilla/tazetta extractNarcissus Jonquilla ExtractNarcissus Tazetta Extract90064-25-8
Pelargonium graveolens oilPelargonium Graveolens Flower Oil90082-51-28000-46-2
Pogostemon cablin oilPogostemon Cablin Oil8014-09-3 84238-39-1
Rosa damascena flower oil/extract;Rosa Damascena Flower Oil; Rosa Damascena Flower Extract8007-01-090106-38-0
Rosa alba flower oil/extract;Rosa Alba Flower Oil; Rosa Alba Flower Extract93334-48-6
Rosa canina flower oil;Rosa Canina Flower oil;84696-47-9
Rosa centifolia oil/extract;Rosa Centifolia Flower Oil; Rosa Centifolia Flower Extract84604-12-6
Rosa gallica flower oil;Rosa Gallica Flower Oil;84604-13-7
Rosa moschata flower oil;Rosa Moschata Flower Oil;–
Rosa rugosa flower oilRosa Rugosa Flower Oil92347-25-6
Santalum album oilSantalum Album Oil8006-87-984787-70-2
Phenol, 2-methoxy-4-(2-propenyl)-, acetateEugenyl Acetate93-28-7
2,6-Octadien-1-ol, 3,7-dimethyl-,1-acetate, (2E)-Geranyl Acetate105-87-3
2-Methoxy-4-prop-1-enylphenyl acetateIsoeugenyl Acetate93-29-8
2,6,6-Trimethylbi-cyclo[3.1.1]hept-2-ene (alpha-Pinene);6,6-Dimethyl- 2-methylenebicyclo[3.1.1]heptane (beta-Pinene)Pinene80-56-87785-70-8127-91-318172-67-3