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Trimethylcyclopentenyl Methylisopentenol
"Descrizione"
by Al222 (24891 pt)
2026-Jan-04 21:20

Trimethylcyclopentenyl Methylisopentenol

Synonyms: Ebanol, 3-Methyl-5-(2,2,3-Trimethyl-3-Cyclopentenyl) pent-4-en-2-ol (chemical name), isomer mixture (grade-dependent specification)
INCI / functions: fragrance (perfuming)

Definition

Trimethylcyclopentenyl Methylisopentenol is a synthetic odorant belonging to the terpenoid family (terpenic alcohols), used in perfumery for a woody “sandalwood-like” note and as a building block in fragrance accords. From a compositional standpoint, the ingredient mainly consists of 3-Methyl-5-(2,2,3-Trimethyl-3-Cyclopentenyl) pent-4-en-2-ol (often marketed as an isomer mixture), with possible controlled trace process-related impurities within the supplier’s specification limits. In cosmetics, its function is primarily perfuming; use is driven by compliance requirements (allergen/labeling) and formulation compatibility (solubilization, olfactory stability, packaging).

  • Cosmetics: fragrance (perfuming); subject to labeling obligations above threshold (see regulatory section).

  • Industrial use: component for technical perfumery, fragrance accords, and industrial formulations requiring a specific woody note.

Identification data and specifications

ParameterValue
Name (INCI)Trimethylcyclopentenyl Methylisopentenol
Reported substance/ingredient (EU annexes)3-Methyl-5-(2,2,3-Trimethyl-3-Cyclopentenyl) pent-4-en-2-ol
Molecular formulaC₁₄H₂₄O
Molar mass208.34 g/mol
CAS number67801-20-1
EC number267-140-4


Key constituents

ClassMain componentsTechnical note
Terpenic alcohols / terpenoidstarget substance (often as an isomer mixture)primary driver of olfactory profile and physical behavior
Minor components (grade-dependent)minor fractions/isomers, impurities within speccan affect repeatability and olfactory stability
Controlled tracesprocess residues within limitsrelevant for QC and SDS/CoA compliance


Physicochemical properties (formulation-relevant)

PropertyIndicative value
Physical stateliquid
Colorcolorless to pale yellow (grade-dependent)
Water solubilityvery low / practically insoluble
Solubilitysoluble in many organic solvents and fragrance bases
Boiling point~283 °C (indicative)
Flash point~108 °C (indicative)
Density~0.9 (indicative)


Functional role in formulation

FunctionWhat it does in the formulaOperational notes
Fragranceprovides a woody, warm, rounded note in fragrance accordsperformance depends on the matrix, synergy with other odorants, and long-term stability


Formulation compatibility

System / variableCompatibilityControl notes
Emulsions and fragranced aqueous systemsto be assessedoften requires solubilizers; haze risk if fragrance load is high
Surfactant systems (rinse-off)often compatibleverify clarity, hot/cold olfactive profile, interaction with polymers
Transparent polymer gelssensitivepotential loss of clarity: optimize solubilization and addition order
Packagingcautionrun tests with plastics/seals (migration, stress cracking)
Olfactory stabilitycriticalmonitor oxidation/note drift with light, air, and temperature


Use guidelines (indicative)

ContextTypical rangeTechnical note
Cosmetics (as a fragrance component)trace – 0.1% (order of magnitude)actual level depends on the fragrance concentrate and target profile
Technical/industrial perfumeryvariabledefine per specifications, VOC requirements, and process safety


Typical applications

  • Fragranced leave-on products (creams, lotions, deodorants) and rinse-off products (shampoos, shower gels) as part of the fragrance composition.

  • Modern woody accords and fragrance bases where a warm/persistent effect is desired.

Quality, grades and specifications

TopicDetail
Gradesperfumery, technical/industrial (variable specs and purity)
Recommended controlsidentity and GC profile, purity/isomer ratio, color/odor, water, oxidation stability markers (if specified)
Documentationup-to-date CoA and SDS to align quality, safety, and applicable limits


Safety, regulation and environment

TopicOperational guidance
EU framework (restrictions)Cosmetic ingredient subject to restriction III/339 as a relevant entry in the annexes of EU Cosmetics Regulation update (EU) 2023/1545 (fragrance allergen update)
Reported substance/ingredient3-Methyl- 5-(2,2,3-Trimethyl- 3-Cyclopentenyl) pent-4-en-2-ol
Labeling obligation (Art. 19(1)(g))presence must be indicated in the ingredients list when exceeding the thresholds reported below
Practical hazards (SDS, grade-dependent)possible skin sensitization; possible aquatic environmental hazards; apply risk assessment and spill management
Storagetightly closed containers, cool conditions; minimize light/air exposure to limit olfactive drift; follow SDS
Environmentavoid release; manage residues according to classification and local regulations


Product typeLabeling threshold
Leave-on0.001%
Rinse-off0.01%


Formulation troubleshooting

IssuePossible causeCorrective actions
Haze in aqueous systemsinsufficient fragrance solubilizationuse a suitable solubilizer, pre-dilute in fragrance phase, optimize addition order
Note drift over timethermal stress, light, oxygen, matrix interactionsbarrier packaging, compatible antioxidants in the fragrance, controlled storage conditions
Packaging interactionpolymer/seal incompatibilityaccelerated testing, switch materials (e.g., glass or compatible plastics), reduce fragrance load
Label non-compliancethresholds exceeded without declarationcalculate finished-product concentration, verify fragrance CoA/IFRA info, update labeling artwork


Conclusion

Trimethylcyclopentenyl Methylisopentenol is a perfuming ingredient used to build modern woody notes, technically manageable but governed by two critical points: (1) EU compliance as a fragrance allergen entry requiring labeling above 0.001% in leave-on and 0.01% in rinse-off products; (2) formulation robustness driven by solubilization, olfactive stability, and packaging compatibility. Proper use requires grade selection, QC alignment (GC/CoA), and consistency with SDS and labeling requirements.

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