Fragrance allergens / Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde
Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde
Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde is prohibited in cosmetic products in the EU, Northern Ireland and Great Britain: the EU Annex II and the Great Britain one both list it as entry 1380. Great Britain's Annex III still carries its old declaration condition, because the part of Reg (EU) 2017/1410 that deleted it took effect after the UK left, so it remains on the GB declarable list. A product containing it still cannot be sold in any of the three.
Identity
| Name in the ingredient list | Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde |
|---|---|
| CAS / EC numbers | 51414-25-6 / EC 257-187-931906-04-4 / EC 250-863-4 |
| GB Annex III entry | 79 |
| Annex II entry (prohibited) | 1380, in the EU and the GB text |
When it must appear on the label
Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde may be present as a constituent of essential oils or fragrance compounds. It must be named individually in the ingredient list when its total concentration in the finished product exceeds 0.001% in leave-on products (lotions, balms) or 0.01% in rinse-off products (soap, shower gel), summed across every fragrance source in the recipe. Below the threshold it stays within the collective term "Parfum".
For Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde the threshold matters only because the Great Britain Annex III row survives: the substance itself is prohibited in all three regions (Annex II, entry 1380). Our tool declares it on a GB label if a supplier sheet lists it, and warns you that the product cannot be sold.
United States: no individual fragrance-allergen labelling is in force yet (MoCRA rulemaking pending); fragrance is declared collectively as "Fragrance".
Common questions
Do I have to list Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde on my label?
Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde is prohibited in cosmetic products in the EU, Northern Ireland and Great Britain: the EU Annex II and the Great Britain one both list it as entry 1380. Great Britain's Annex III still carries its old declaration condition, because the part of Reg (EU) 2017/1410 that deleted it took effect after the UK left, so it remains on the GB declarable list. A product containing it still cannot be sold in any of the three. If your supplier's sheet lists it, ask for a fragrance without it.
What is the CAS number for Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde?
Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde is listed under CAS 51414-25-6, 31906-04-4 (EC 257-187-9, 250-863-4).
Tell me if Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde changes
Hydroxyisohexyl 3-Cyclohexene Carboxaldehyde is prohibited in cosmetics in the EU, Northern Ireland and Great Britain, while the Great Britain Annex III still carries its old declaration row. When either text changes, we update the rule tables and email you.
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Sources
- Assimilated Regulation (EC) No 1223/2009, Annex III, as it applies in Great Britain, entries carrying the individual-declaration condition (legislation.gov.uk)
- Regulation (EC) No 1223/2009, Annex II, prohibited substances (consolidated text of 18.05.2026), entry 1380 (EUR-Lex)
- Assimilated Regulation (EC) No 1223/2009, Annex II, prohibited substances, as it applies in Great Britain, entry 1380 (legislation.gov.uk)
Transcribed from the official texts linked above and checked against them; a labelling reference, not safety advice. You remain responsible for your product's labelling.
Rule tables last checked 25 September 2026.