Colorless viscous liquid to white crystalline solid (mp 40-41°C)
Odor Strength
Medium
Producing Countries
China, Germany, India, United States
Pyramid
Heart
Lilac petals crushed between resinous fingers. Alpha-terpineol smells like the clean inside of a freshly sawn pine board dusted with spring flowers — the molecule responsible for the scent most people call 'pine-fresh,' though the floral side dominates on skin.
At full concentration: pine-terpenic and lilac-floral simultaneously, with a soapy, slightly camphoraceous lift — like pressing your nose into a bar of violet-scented soap left on a pine shelf. Cleaner and less herbaceous than linalool, more floral than pinene, softer than borneol. At 1% dilution: the pine recedes sharply, leaving a woody-resinous character with a cooling citrus layered (lemon-lime). On further dilution below 0.1%: a sweet peach-like softness emerges, unexpected from such a terpenic molecule. The soapy-clean quality persists across all concentrations and is the reason alpha-terpineol dominates functional perfumery — it is the actual molecule behind what most people identify as the smell of pine-fresh household cleaner.
Evolution over time
Immediately
Immediately
Sharp pine-terpenic burst with a lilac-floral overlay. Soapy, bright, slightly camphoraceous. A citrus-lemon nuance flickers at the edges. Clean and assertive.
After a few hours
After a few hours
Pine facet fades significantly. The lilac-floral character clarifies and sweetens. A soft peach-like nuance emerges on skin — rounder, less angular. Soapy-clean undertone persists but quieter.
After a few days
After a few days
Faint, clean, dry residue. Barely perceptible lilac ghost. Soapy warmth on fabric. At 100% concentration, TGSC records approximately 20 hours substantivity — on skin at typical use levels (1-3%), the scent trail is largely gone within 6-8 hours.
Terroir & Origins
Indicative 2025 wholesale prices.
The Full Story
Alpha-terpineol (CAS 98-55-5, MW 154.25, C₁₀H₁₈O) is a tertiary monoterpene alcohol — a consumed aroma chemicals in existence, present in thousands of formulas from fine fragrance to laundry detergent. At full strength it smells simultaneously of lilac and pine, as if two scents are fighting for dominance on the same strip. At 1% in ethanol, the profile shifts: pine-like, woody, resinous, with a cooling lem on-lime citrus layered (TGSC). On skin at trace levels, the pine vanishes entirely and a soft peach-like sweetness emerges. This concentration-dependent personality is the molecule's defining characteristic.
The commercial product is synthesized from alpha-pinene — the dominant terpene in turpentine — via acid-catalyzed hydration through a terpin hydrate intermediate. The process yields a mixture of alpha (70%), beta (20%), and gamma (10%) terpineol isomers. The alpha isomer crystallizes at 40-41°C and can be isolated as a white solid, though most perfumery-grade material is sold as a colorless viscous liquid (bp 214-218°C, SG 0.930-0.936, RI 1.474-1.486). Production is anchored to turpentine supply from China, the United States, and India.
In fine perfumery, alpha-terpineol is a modifier, not a star. It reinforces lilac and muguet accords with a clean, soapy transparency. It provides the terpenic bridge in fougere compositions between lavender and coumarin. Combined with linalool and linalyl acetate, it generates the classical clean-aromatic masculine signature. Its odor threshold — 280 to 350 ppb — places it in the mid-range: not subtle enough to vanish at trace levels, not aggressive enough to dominate without dosage. Substantivity at 100% is approximately 20 hours (TGSC). Note: alpha-terpineol is unstable in alkaline formulations and becomes imperceptible in soap bases.
The molecule occurs naturally in over 150 essential oils. In tea tree oil (Melaleuca alternifolia), it constitutes 1.5-8% per ISO standards (typically 3-5% by GC-MS). It appears in cajuput, pine, petitgrain bigarade, and neroli oils, though extraction from natural sources is not economically viable given synthetic production costs. As of 2023, alpha-terpineol is classified as a EU fragrance allergen under Regulation 2023/1545, requiring mandatory labeling above 0.001% in leave-on products and 0.01% in rinse-off products (compliance deadline: July 2026).
Terpin hydrate — made by hydrating alpha-pinene through the same intermediate that yields alpha-terpineol — was one of America's most popular cough syrups for over a century, often combined with codeine. The FDA pulled it from pharmacy shelves in the early 1990s for lack of efficacy evidence. The molecule you smell in floor cleaner was once prescribed medicine.
Extraction & Chemistry
Extraction method: Commercial alpha-terpineol is synthesized in two steps from turpentine-derived alpha-pinene: (1) acid-catalyzed hydration of alpha-pinene with ~30% sulfuric acid yields crystalline cis-terpin hydrate (mp 117°C); (2) partial dehydration of terpin hydrate produces a mixture of alpha-, beta-, and gamma-terpineol in approximately 7:2:2 ratio. The alpha isomer is isolated by fractional distillation or crystallization (mp 40-41°C). Modern one-step routes using tartaric acid/boric acid composites or solid acid catalysts achieve 96% pinene conversion at 60°C. Natural isolation from essential oils (cajuput, pine, petitgrain) is not economical. Global production is tied to turpentine supply, primarily from China, the United States, and India.
Not restricted under IFRA Amendment 51. However, classified as an EU fragrance allergen under Regulation 2023/1545 (Annex III). Mandatory label declaration required above 0.001% in leave-on products and 0.01% in rinse-off products. Compliance deadline: July 31, 2026 (new products), July 31, 2028 (existing products). TGSC max skin level in fine fragrance: 5.7%. FDA GRAS (FEMA 3045).
Colorless viscous liquid to white crystalline solid (mp 40-41°C)
Boiling Point
214.00 to 218.00 °C @ 760.00 mm Hg
Flash Point
191.00 °F TCC (88.33 °C)
Specific Gravity
0.93000 to 0.93600 @ 25.00 °C
Refractive Index
1.47400 to 1.48600 @ 20.00 °C
Melting Point
40.00 to 41.00 °C @ 760.00 mm Hg
In Perfumery
Alpha-terpineol (CAS 98-55-5) is a monoterpene alcohol that functions as a floral modifier and terpenic bridge. Its dual character — lilac-floral at low concentration, pine-terpenic at high — determines its placement in a formula. Below 2%, it lifts floral compositions with a dewy, soapy-clean transparency: lilac, muguet, and freesia accords depend on it. Above 5%, the piney quality takes over and the molecule reads as a cleaning product. Recommended maximum in the fragrance concentrate: 5.7% (TGSC). In fougère structures, alpha-terpineol provides the terpenic link between lavender top notes and coumarin-mossy base. Combined with linalool and linalyl acetate, it generates the classical 'clean aromatic' masculine signature. It also bridges green-citrus top notes into woody hearts. Compatible with dihydromyrcenol for fresh-aromatic effects, with hydroxycitronellal for muguet accords, and with terpinyl acetate (CAS 80-26-2) for enhanced lilac. It is unstable in alkaline bases — in soap formulations, its scent becomes imperceptible. Classified as a EU allergen under Regulation 2023/1545 (Annex III): mandatory labeling above 0.001% in leave-on products, 0.01% in rinse-off (effective July 2026 for new products). Present in two Première Peau compositions: Insuline Safrine and Gravit as Capitale, where it contributes to the terpenic-aromatic quality.
