alpha-ionol

Alpha-ionol, chemically described as 4-(2,6,6-trimethyl-2-cyclohexenyl)but-3-en-2-ol, is an organic compound notable for its pleasant floral and woody aroma. It is recognized under multiple synonyms including a-ionol and Latilure, reflecting its varied industrial usages. This compound has a molecular formula of C₁₃H₂₂O and is registered in authoritative chemical databases such as PubChem, where it is indexed under CID 5363817. Alpha-ionol is typically isolated from natural sources like champaca concrete and raspberry fruit, contributing characteristic floral and berry notes to these materials. It finds broad application in flavoring and perfumery, where its ionone-like scent adds complexity to formulations.

Alpha-ionol naturally occurs in plant extracts such as champaca concrete at approximately 0.10% and in red raspberry fruits. Its sensory qualities, including floral, woody, and berry-like odors, make it valuable for use as a flavor and fragrance agent. According to FEMA (US) standards, alpha-ionol is designated with number 3624 and is employed in cherry, berry, spice, and nut flavorings, as well as in perfuming agents. It is relevant in formulation contexts requiring floral and woody notes, often augmenting violet, powdery, and fruity nuances. Its use levels are regulated by IFRA (Global), ensuring safe concentration limits in consumer products.

Alpha-ionol presents with moderate specific gravity between 0.917 and 0.924 at 25 °C and a refractive index ranging from 1.488 to 1.492 at 20 °C. It has a low vapor pressure of approximately 0.001 mmHg at 25 °C, indicating low volatility under ambient conditions. The compound has a molecular weight near 194.3 g/mol and demonstrates estimated logP values around 4.49, suggesting considerable lipophilicity. Solubility characteristics include partial solubility in alcohol and limited solubility in water, with an estimated aqueous solubility of 21.02 mg/L at 25 °C. Its flash point is measured at 200 °F (~93 °C), which informs handling and formulation safety practices. These properties influence alpha-ionol’s incorporation in liquid flavor and fragrance formulations, impacting stability and release profiles.

(IUPAC):	Atomic Weights of the Elements 2011 (pdf)
Videos:	The Periodic Table of Videos
tgsc:	Atomic Weights use for this web site
(IUPAC):	Periodic Table of the Elements
FDA Substances Added to Food (formerly EAFUS):	View
HMDB (The Human Metabolome Database):	HMDB38731
FooDB:	FDB018141
Export Tariff Code:	2906.19.5000
Typical G.C.
VCF-Online:	VCF Volatile Compounds in Food
ChemSpider:	View

Safety information

Preferred SDS: View
European information :
Most important hazard(s):
Xi - Irritant
R 36/38 - Irritating to skin and eyes. S 02 - Keep out of the reach of children. S 24/25 - Avoid contact with skin and eyes. S 26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S 36 - Wear suitable protective clothing.
Hazards identification
Classification of the substance or mixture
GHS Classification in accordance with 29 CFR 1910 (OSHA HCS)
None found.
GHS Label elements, including precautionary statements
Pictogram
Hazard statement(s)
None found.
Precautionary statement(s)
None found.
Oral/Parenteral Toxicity:
oral-rat LDLo 5000 mg/kg Food and Chemical Toxicology. Vol. 26, Pg. 359, 1988.
Dermal Toxicity:
skin-rabbit LD50 > 5000 mg/kg Food and Chemical Toxicology. Vol. 26, Pg. 359, 1988.
Inhalation Toxicity:
Not determined

Safety in use information

Category:
flavor and fragrance agents
RIFM Fragrance Material Safety Assessment: Search
IFRA Code of Practice Notification of the 49th Amendment to the IFRA Code of Practice
Recommendation for alpha-ionol usage levels up to:
	8.0000 % in the fragrance concentrate.
Maximised Survey-derived Daily Intakes (MSDI-EU):		0.61 (μg/capita/day)
Maximised Survey-derived Daily Intakes (MSDI-USA):		0.06 (μg/capita/day)
Structure Class:		I
Use levels for FEMA GRAS flavoring substances on which the FEMA Expert Panel based its judgments that the substances are generally recognized as safe (GRAS).
The Expert Panel also publishes separate extensive reviews of scientific information on all FEMA GRAS flavoring substances and can be found at FEMA Flavor Ingredient Library
publication number: 12
Click here to view publication 12
		average usual ppm	average maximum ppm
baked goods:		-	3.00000
beverages(nonalcoholic):		-	1.00000
beverages(alcoholic):		-	-
breakfast cereal:		-	-
cheese:		-	-
chewing gum:		-	5.00000
condiments / relishes:		-	-
confectionery froastings:		-	2.00000
egg products:		-	-
fats / oils:		-	-
fish products:		-	-
frozen dairy:		-	2.00000
fruit ices:		-	1.50000
gelatins / puddings:		-	2.00000
granulated sugar:		-	-
gravies:		-	-
hard candy:		-	4.00000
imitation dairy:		-	2.00000
instant coffee / tea:		-	-
jams / jellies:		-	2.00000
meat products:		-	-
milk products:		-	2.00000
nut products:		-	-
other grains:		-	-
poultry:		-	-
processed fruits:		-	-
processed vegetables:		-	-
reconstituted vegetables:		-	-
seasonings / flavors:		-	-
snack foods:		-	-
soft candy:		-	2.50000
soups:		-	-
sugar substitutes:		-	-
sweet sauces:		-	-

Safety references

European Food Safety Athority(EFSA):Flavor usage levels; Subacute, Subchronic, Chronic and Carcinogenicity Studies; Developmental / Reproductive Toxicity Studies; Genotoxicity Studies...

European Food Safety Authority (EFSA) reference(s):

Flavouring Group Evaluation 210: alpha,beta-Unsaturated alicyclic ketones and precursors from chemical subgroup 2.4 of FGE.19[1] View page or View pdf

Scientific Opinion on Flavouring Group Evaluation 210 Revision 2 (FGE.210Rev2): Consideration of genotoxic potential for a,ß-unsaturated alicyclic ketones and precursors from chemical subgroup 2.4 of FGE.19 View page or View pdf

EPI System: View

AIDS Citations:Search

Cancer Citations:Search

Toxicology Citations:Search

EPA Substance Registry Services (TSCA):25312-34-9

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :5363817

National Institute of Allergy and Infectious Diseases:Data

WGK Germany:2

4-(2,6,6-trimethyl-1-cyclohex-2-enyl)but-3-en-2-ol

Chemidplus:0025312349

RTECS:EM9630050 for cas# 25312-34-9