Fragrance Allergens in Consumer Products — The 26 EU-Regulated Sensitizers and What They Mean

Why Does Your “Unscented” Product Still Trigger an Allergic Reaction?

“Unscented” means the product has no perceivable scent — it may still contain fragrance chemicals added to mask the smell of other ingredients. “Fragrance-free” means no fragrance chemicals were added. This distinction matters: the EU requires labeling of 26 specific fragrance allergens when they exceed concentration thresholds (0.001% in leave-on products, 0.01% in rinse-off). These 26 allergens are the most common contact sensitizers, responsible for 1-3% of the general population and 10-15% of dermatology patients experiencing fragrance-related contact dermatitis.

The 26 EU-regulated fragrance allergens

Allergen	CAS Number	Found in	Patch test positive rate	Frequency in products
Linalool	78-70-6	Lavender, citrus, many essential oils	5-7% of tested patients	Very common (>60% of scented products)
Limonene	5989-27-5	Citrus oils, cleaning products	3-5%	Very common (>50%)
Citronellol	106-22-9	Rose, geranium oil	2-4%	Common (30-40%)
Geraniol	106-24-1	Rose, palmarosa, citronella	3-5%	Common (30-40%)
Citral	5392-40-5	Lemongrass, lemon myrtle	2-4%	Common (20-30%)
Coumarin	91-64-5	Tonka bean, cassia cinnamon	1-3%	Common (20-30%)
Eugenol	97-53-0	Clove oil, cinnamon	2-4%	Moderate (15-25%)
Cinnamal (cinnamaldehyde)	104-55-2	Cinnamon bark	2-5%	Moderate (15-20%)
Hydroxycitronellal	107-75-5	Synthetic (lily of the valley scent)	2-4%	Moderate (15-25%)
Isoeugenol	97-54-1	Ylang ylang, nutmeg	2-5%	Moderate (10-20%)
HICC (Lyral)	31906-04-4	Synthetic (floral)	3-6%	Restricted (EU ban 2021)
Cinnamyl alcohol	104-54-1	Cinnamon, storax balsam	1-3%	Moderate (10-20%)
Farnesol	4602-84-0	Linden, chamomile	1-3%	Moderate (10-15%)
Oak moss (Evernia prunastri)	90028-68-5	Natural extract	5-8%	Limited (5-10%)
Tree moss (Evernia furfuracea)	90028-67-4	Natural extract	3-6%	Limited (5-10%)

Labeling requirements comparison

Requirement	EU (Cosmetics Regulation 1223/2009)	US (FDA)	Singapore (HSA)
Individual allergen labeling	Required above threshold	Not required (“fragrance” permitted)	Follows EU approach for cosmetics
Threshold (leave-on)	0.001% (10 ppm)	N/A	0.001%
Threshold (rinse-off)	0.01% (100 ppm)	N/A	0.01%
Number of regulated allergens	26 (expanding to 80+ in 2026)	0 specific allergens	26 (aligned with EU)
“Fragrance” as catch-all	Not permitted for regulated allergens	Permitted (hides ingredients)	Not permitted for regulated allergens

Contact dermatitis risk by product category

Product category	Avg number of fragrance allergens	Skin contact duration	Risk level
Perfume/eau de toilette	15-25	Hours (skin application)	Highest
Body lotion/cream	5-15	Hours (skin application)	High
Shampoo/conditioner	5-12	Minutes (rinse-off)	Medium
Laundry detergent	3-8	Indirect (residue on fabric)	Low-medium
Household cleaners	3-10	Minutes (inhalation + contact)	Low-medium
Candles/air fresheners	5-15	Inhalation	Low (but sensitization possible)

Practical avoidance strategies

Strategy	Effectiveness	Effort	For whom
Choose “fragrance-free” (not “unscented”)	High	Low	Everyone with sensitive skin
Read INCI ingredient lists for specific allergens	Highest	Medium	Diagnosed contact allergy
Patch test new products (inner forearm, 48h)	High for detection	Low	History of reactions
Use fragrance allergen scanner apps (Yuka, INCI Beauty)	Moderate	Low	General precaution
Request allergen-free formulations from dermatologist	Highest	Medium	Severe contact dermatitis

Quick Reference Summary

Allergen group	Most common compounds	Found in	Avoidance
Floral	Linalool, geraniol, citronellol	Perfumes, lotions, shampoos	”Fragrance-free” products
Citrus	Limonene, citral	Cleaning products, citrus oils	Unscented cleaners
Spice	Cinnamal, eugenol, isoeugenol	Cinnamon, clove, some foods	Ingredient list checking
Tree/wood	Oak moss, tree moss, coumarin	Perfumes, candles	Avoid “woody” or “forest” scents
Synthetic	HICC, hydroxycitronellal	Perfumes, detergents	EU-banned (HICC), read labels

How to apply this

Use the ingredient-checker tool to evaluate product contents to verify ingredient safety based on the data above.

Start by checking the ingredient list of your products against the reference tables above.

Use the ingredient-checker tool to evaluate specific compounds you find on product labels.

Check concentration levels against the safety thresholds listed in the comparison tables.

Avoid products where the risk indicators from the tables suggest exposure above recommended limits.

Replace flagged items with the safer alternatives identified in the substitution recommendations.

Verify new products against the same criteria before adding them to your routine.

Honest Limitations

• Patch test data comes from dermatology patients, not general population: The 2-7% positive rates are from patients already suspected of contact allergy. Population-wide sensitization rates are lower (0.5-2%) but still clinically significant.
• Oxidized forms cause most reactions: Linalool and limonene are relatively safe when fresh. Their oxidation products (linalool hydroperoxides, limonene hydroperoxides) are the actual sensitizers. Products stored for long periods have higher sensitizer concentrations.
• The EU allergen list is expanding: The Scientific Committee on Consumer Safety (SCCS) recommended expanding from 26 to 80+ regulated allergens. This is in progress but not yet implemented. Current labeling doesn’t capture all problematic allergens.
• “Natural” fragrances contain the same allergens: Essential oils (lavender, citrus, rose) contain the same allergen compounds as synthetic fragrances. “Natural fragrance” is not hypoallergenic.
• Cross-reactivity exists: Someone allergic to cinnamal may also react to cinnamyl alcohol and eugenol (structurally related). Avoiding one allergen may not prevent reactions from related compounds.