nopyl acetate

Nopyl acetate is a bicyclic acetate ester chemically identified by the molecular formula C₁₃H₂₀O₂. It is characterized by a pale clear appearance and has a distinctive medium herbal odor profile with pronounced woody and fruity nuances. The compound is also recognized under several synonyms including nopol acetate, lignyl acetate, and 6,6-dimethyl bicyclo(3.1.1)hept-2-ene-2-ethanol acetate. Its olfactory qualities find frequent use in fragrance formulations. The chemical structure comprises a bicyclo[3.1.1]heptene core substituted with an acetate group, linking it to various naturally derived terpene alcohols. Nopyl acetate can be found sourced from specialty chemical suppliers and is cataloged under the CAS number 128-51-8. For precise chemical information, this compound is recorded in the PubChem database under the identifier 101604. In formulations, it serves primarily as a scent ingredient imparting herbal and woody notes that persist after application.

Nopyl acetate occurs primarily as a synthetic derivative designed to mimic some naturally occurring bicyclic terpene esters. Its key application is as a fragrance ingredient where it is utilized for imparting medium substantivity herbal, woody, and fruity notes. The compound appears frequently in citrus, orange-flower, and fougere type fragrance blends, as well as in household scent compositions. It can contribute to balsam, bergamot, cedar, pine, floral, and marine scent accords. Regulatory frameworks such as IFRA (Global) provide recommended maximum usage levels to guide safe formulation practices. Nopyl acetate is not intended for use as a flavoring agent. Its presence in cosmetic and personal care products is carefully monitored according to these standards to ensure appropriate consumer exposure and safety.

Nopyl acetate exhibits physicochemical properties that influence its performance and stability in fragrance compositions. It has a molecular weight of approximately 208.3 g/mol with a chemical formula of C₁₃H₂₀O₂. The compound’s specific gravity ranges from 0.977 to 0.985 at 20 °C, indicating a density slightly less than water. Its refractive index at 20 °C lies between 1.471 and 1.474, typical of many fragrant esters. The vapor pressure is low at 0.008 mmHg at 25 °C, corresponding to moderate volatility which contributes to its substantivity on skin and materials. The estimated octanol-water partition coefficient (log P) is around 3.9, suggesting lipophilicity compatible with fragrance diffusion and skin adherence. Nopyl acetate is soluble in alcohol but has limited water solubility. Its flash point is reported at 225 °F (~107 °C), necessitating storage in cool, dry places away from heat and light. Shelf life is approximately 24 months under proper conditions. These properties collectively facilitate its use in formulations requiring lasting aromatic effects with acceptable safety considerations.

	2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethyl acetate
NIST Chemistry WebBook:	Search Inchi
Canada Domestic Sub. List:	128-51-8
Pubchem (cid):	101604
Pubchem (sid):	135059770
Pherobase:	View

(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
CHEMBL:	View
HMDB (The Human Metabolome Database):	Search
Export Tariff Code:	2915.39.9050
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Safety information

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)
Acute toxicity, Oral (Category 4), H302
GHS Label elements, including precautionary statements
Pictogram
Signal word	Warning
Hazard statement(s)
H302 - Harmful if swallowed
Precautionary statement(s)
P264 - Wash skin thouroughly after handling. P270 - Do not eat, drink or smoke when using this product. P301 + P312 - IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell. P330 - Rinse mouth. P501 - Dispose of contents/ container to an approved waste disposal plant.
Oral/Parenteral Toxicity:
oral-rat LD50 3000 mg/kg Food and Cosmetics Toxicology. Vol. 12, Pg. 943, 1974.
Dermal Toxicity:
Not determined
Inhalation Toxicity:
Not determined

Safety in use information

Category:
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 nopyl acetate usage levels up to:
	25.0000 % in the fragrance concentrate.
Recommendation for nopyl acetate flavor usage levels up to:
	not for flavor use.

Safety references

EPI System: View

AIDS Citations:Search

Cancer Citations:Search

Toxicology Citations:Search

EPA Substance Registry Services (TSCA):128-51-8

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :101604

National Institute of Allergy and Infectious Diseases:Data

WGK Germany:2

2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)ethyl acetate

Chemidplus:0000128518