Nerol

NEROL Technical Ingredient Overview

• 🔎 Chemical Name — (Z)-3,7-Dimethylocta-2,6-dien-1-ol

• 🧪 Synonyms — cis-Geraniol; (2Z)-3,7-Dimethyl-2,6-octadien-1-ol; Neryl alcohol; Nerolex; Vernol

• 📂 CAS Number — 106-25-2

• 📘 FEMA Number — 2770

• ⚖️ Molecular Weight — 154.25 g/mol

• 📝 Odor Type — Floral-citrus (Middle note)

• 📈 Odor Strength — Medium to strong; moderate tenacity

• 👃🏼 Odor Profile — Fresh, sweet rose-like odor with neroli and citrus facets; wet seashore character; greener and fresher than geraniol

• ⚗️ Uses — Rose compositions, neroli accords, floral fragrances, citrus flavor bouquets

• 🧴 Appearance — Colorless to pale yellow oily liquid

What is Nerol?

Nerol is an acyclic monoterpene alcohol and the cis-isomer of geraniol, representing one of the fundamental building blocks in natural perfumery. With molecular formula C₁₀H₁₈O, nerol contains two double bonds in the carbon chain with the characteristic Z-(cis) configuration at the 2-position, distinguishing it from its more common trans-isomer, geraniol. This stereochemical difference results in distinctly different olfactory properties despite identical molecular weights and formulas (Surburg & Panten, 2006).

Nerol belongs to the acyclic terpene alcohol family and serves as both a fragrance ingredient and a key synthetic intermediate for producing other important materials including citronellol, citral, and various esters. The molecule's structure features a primary alcohol functional group, making it reactive for esterification and oxidation reactions (Bauer et al., 2001).

Historical Background

Nerol derives its name from neroli oil, the steam-distilled essential oil of bitter orange blossoms (Citrus aurantiumsubsp. amara), where it was first identified as a natural constituent alongside its isomer geraniol. The compound has been recognized in perfumery since the late 19th century when advances in analytical chemistry enabled the identification of individual components in essential oils (Arctander, 1960).

Historically, nerol was isolated from natural sources including citronella oil, palmarosa oil, and lemongrass oil. The development of large-scale synthetic production routes in the mid-20th century, particularly from β-pinene via myrcene, revolutionized the availability of nerol for industrial applications (Bauer et al., 2001). These synthetic routes, developed initially to support vitamin E production, made nerol economically accessible for widespread use in fragrance compositions.

Olfactory Profile

• Scent Family: Floral-Rose with Citrus aspects

• Main Descriptors: Sweet, fresh rose, neroli-like, magnolia, citrus, wet seashore, green, natural

• Intensity: Medium strength with moderate persistence; less tenacious than geraniol but more refined

• Tenacity: Moderate longevity as a middle note; performs best in the heart phase of fragrance development

• Volatility: Middle note character; evaporates more slowly than citrus notes but faster than woody materials

The olfactory character of pure nerol emphasizes fresh seashore and wet marine facets, with less pronounced rosy aspects compared to geraniol. High geraniol content in commercial nerol grades masks these maritime notes, shifting the profile toward deeper rose tones. Nerol is considered fresher and greener than its trans-isomer, with enhanced neroli and magnolia-like qualities.

Applications in Fine Fragrance

Nerol is used in perfumery for the same applications as geraniol, particularly in rose compositions where it imparts freshness and natural character, but also finds extensive use in other blossom compositions including neroli, petitgrain, bergamot, wallflower, lindenflower, magnolia, lilac, violet, jasmine, and muguet accords. The material blends exceptionally well with citrus oils and floral absolutes, contributing to classic eau de cologne formulations.

In flavor applications, nerol serves as a bouqueting agent in citrus flavors, enhancing naturalness and complexity. Technical-grade nerol, often supplied as a mixture with geraniol, functions as an important intermediate in citronellol and citral production (Surburg & Panten, 2006).

Performance in Formula

Nerol demonstrates good stability in alcoholic solutions and typical fragrance carriers, though it is more prone to acid-catalyzed cyclization than geraniol, readily forming monocyclic terpene structures. This reactivity necessitates careful pH control in formulations. The material shows excellent compatibility with both natural and synthetic components, serving as a versatile blending tool.

Typical usage concentrations range from 0.1-5% in fine fragrance and 0.05-2% in functional applications. Nerol exhibits better solubility in alcohol than in water, making it suitable for eau de toilette and parfum formulations.

Industrial & Technical Uses

Beyond fragrance, nerol serves as a chemical intermediate in the synthesis of various terpene derivatives. The material undergoes hydrogenation to produce dihydronerol and tetrahydrogeraniol, rearrangement to yield citronellal, and oxidation to form citral. These transformations make nerol valuable in the production of vitamins, pharmaceuticals, and specialty chemicals (Bauer et al., 2001).

Regulatory & Safety Overview

• IFRA Status: Not restricted under IFRA Amendment 51; classified as a standard fragrance alcohol

• EU Cosmetics Regulation: Compliant for use in cosmetic products; not classified as a fragrance allergen requiring mandatory declaration under Regulation 1223/2009

• FEMA Status: FEMA 2770 - Generally Recognized as Safe (GRAS) for use in food flavoring

• Toxicology: Acute oral LD₅₀ in rats: 4.5 g/kg; acute dermal LD₅₀ in rabbits exceeded 5 g/kg. Low toxicity profile suitable for fragrance and flavor applications.

References

• Arctander, S. (1960). Perfume and flavor materials of natural origin. Elizabeth, NJ: Self-published.

• Bauer, K., Garbe, D., & Surburg, H. (2001). Common fragrance and flavor materials: Preparation, properties and uses(4th ed.). Weinheim: Wiley-VCH.

• Pybus, D. H., & Sell, C. S. (Eds.). (1999). The chemistry of fragrances: From perfumer to consumer. Cambridge: Royal Society of Chemistry.

• Surburg, H., & Panten, J. (2006). Common fragrance and flavor materials: Preparation, properties and uses (5th ed.). Weinheim: Wiley-VCH.