How is the allergen concentration calculated when it comes from a fragrance blend?

The concentration threshold applies to the allergen in the finished product. When the allergen is contributed by a fragrance blend, the allergen content of the blend must be multiplied by the percentage of blend used in the formula. If the result exceeds the threshold, the allergen must be declared on the label.

How do I check if my formula contains HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE?

Use the INCI Checker on CosIng Checker to paste your ingredient list. The checker flags all 26 regulated EU allergens including HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE when matched against INCI names in your formula.

What annex entries are associated with CAS 31906-04-4 for HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE?

CAS 31906-04-4 identifies HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE in EU regulatory databases. The linked annex records show all Annex II–VI entries sharing this CAS number, including any restriction or prohibition conditions beyond the allergen labelling requirement.

EU AllergenCAS 31906-04-4

HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE — EU Regulated Fragrance Allergen

Lyral, HICC

HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE is one of 26 fragrance substances required to be declared by INCI name on EU cosmetic product labels under Regulation 1223/2009. Declaration is mandatory when concentration exceeds 0.001% in leave-on products or 0.01% in rinse-off products.

This page links HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE to 1 annex record in the EU cosmetics dataset. Declared on the label when present above 0.001% in leave-on products or 0.01% in rinse-off products under EU Cosmetics Regulation 1223/2009 Annex III.

Leave-on products

> 0.001%

Label declaration required

Rinse-off products

> 0.01%

Label declaration required

Check your formula for this allergen All allergens View annex entries for this CAS

Regulatory status

INCI name

HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE

CAS number

31906-04-4

Synonyms

Lyral, HICC

Declaration requirement

Must be declared on the cosmetic product label when present above 0.001% in leave-on products or above 0.01% in rinse-off products.

Legal basis

EU Cosmetics Regulation 1223/2009, Annex III

Annex records for HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE

Annex

Entry 1380

3 and 4-(4-Hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde

Allergen

Why HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE matters for EU labelling

HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE is one of the 26 fragrance substances that must be declared by INCI name on cosmetic product labels when the finished product exceeds the EU threshold. This page currently links HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE to 1 annex record alongside the core allergen-labelling rule.

Declared on the label when present above 0.001% in leave-on products or 0.01% in rinse-off products under EU Cosmetics Regulation 1223/2009 Annex III.

Allergen declaration is a labelling obligation, not an automatic ban. If additional Annex II or Annex III conditions apply through the linked records above, those conditions must be checked separately from the label declaration thresholds.

Frequently asked questions

HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE is not banned in EU cosmetics — it is a regulated fragrance allergen subject to mandatory labelling. It must be declared by its INCI name on the product label when present above 0.001% in leave-on products or 0.01% in rinse-off products. Some allergens may additionally be restricted or prohibited under Annex II or III; check the linked records above.

Declaration of HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE is mandatory when the concentration exceeds 0.001% (10 ppm) in leave-on cosmetic products or 0.01% (100 ppm) in rinse-off products. Below these thresholds, label declaration is not required but may be made voluntarily.

The concentration threshold applies to the allergen in the finished product. When the allergen is contributed by a fragrance blend, the allergen content of the blend (provided by the fragrance supplier) must be multiplied by the percentage of blend used in the formula. If the calculated total allergen concentration exceeds the threshold, it must be declared on the label.

Use the INCI Checker to paste your ingredient list. The checker flags all 26 regulated allergens including HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE when matched against INCI names in your formula.

Open INCI Checker

CAS 31906-04-4 identifies HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE in the EU regulatory databases. The annex records linked above show all Annex II–VI entries that share this CAS number, including any additional restriction or prohibition conditions beyond the allergen labelling requirement.

Source note for HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE

This page combines the EU allergen-labelling rule for HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE with 1 linked Annex II–VI record drawn from the current local dataset.

Use this page to review labelling logic for HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE, but verify any final compliance decision against the current official allergen rules, annex text and source files.

View sources View updates

Tools & next steps

Check your formula

Scan a full INCI list for HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE, the other EU allergens and any linked annex restrictions.

INCI Checker

All 26 allergens

Browse the complete EU allergen list and compare HYDROXYISOHEXYL 3-CYCLOHEXENE CARBOXALDEHYDE with the other regulated fragrance substances.

View all allergens

Annex entries by CAS

View all EU annex records sharing CAS 31906-04-4.

View CAS records