Thymol

Synthetic Ingredient Overview

• 🏭 Manufacturer: Industrial synthesis (via p-Cymene, Piperitone)

• 🔎 IUPAC Name: 2-Isopropyl-5-methylphenol

• 🧪 Synonyms: Thymol, IPMP

• 🧬 Chemical Formula: C₁₀H₁₄O

• 📂 CAS N°: 89-83-8

• 📘 FEMA: 3066

• ⚖️ MW: 150.22 g/mol

• 📝 Odor Type: Fresh

• 📈 Odor Strength: High (≈176 h on strip at 10% dilution)

• 👃🏼 Odor Profile: Spicy, phenolic, thyme-like; with camphoraceous, medicinal and herbaceous facets

• 👅 Flavor Profile: Sweet-medicinal, spicy-herbaceous, woody; reminiscent of eucalyptol blends

• ⚗️ Uses: Citrus-mint blends, savory herbaceous accords, functional perfumery and flavor applications

• 🧴 Appearance: White crystalline solid

What is Thymol?

Chemically known as 2-isopropyl-5-methylphenol, Thymol is a phenolic monoterpene with deep aromatic roots in Mediterranean botany. Originally isolated from Thymus vulgaris, its structure is closely related to carvacrol, but its scent is softer, warmer, and less tarry. Though often used as a synthetic, it occurs in over a dozen essential oils, including ajowan, monarda, and oregano.

What sets Thymol apart from many phenolic ingredients is its pleasantly medicinal yet aromatic profile. Where phenol or cresol evoke harsh or burnt facets, Thymol remains herbaceous, warm, and almost sweet, particularly at lower dilutions. This makes it a valuable tool for both naturalistic fougères and synthetic herbal-mint compositions.

Thymol’s antiseptic properties, known since antiquity, also contribute to its broad appeal in flavor and pharmaceutical products. Historically, it was used in Middle Eastern za’atar as a digestive aid and antiparasitic, and Native American groups like the Blackfoot employed Monarda spp. (natural thymol sources) to treat skin infections and dental issues.

Olfactory Profile & Perfumery Applications

Thymol is intensely aromatic, working primarily in the top to heart note register. Its opening is sharp and phenolic, with a camphoraceous lift, but it quickly settles into a robust thyme-like warmth.

It works particularly well in:

• Herbal-citrus blends with mint, lime, or mandarin

• Fougère structures, especially with lavender, oakmoss, or coumarin

• Savory-aromatic accords including rosemary, sage, and clove

• Functional perfumery, such as antiseptic-smelling room sprays or dental care formulations

Despite its strength, Thymol integrates easily into compositions. It can be softened with materials like menthol, eucalyptol, terpineol, or even paired with resinoids and aldehydes for retro-medicinal or aromatic blends.

Industrial & Technical Uses

In the flavor and pharma sectors, Thymol plays a dual role as both odorant and bioactive. In flavors, it is used at low ppm levels in:

• Toothpaste, chewing gum, mouthwashes

• Cough drops and lozenges

• Savory spice blends (especially for imitation mandarin, thyme, or oregano)

It also demonstrates:

• Antibacterial activity, by reducing glucose uptake and lactate production

• Antifungal effect, through membrane disruption and hyphal damage

• Synergistic action with chlorhexidine and other antiseptics

In beekeeping, Thymol is used to control Varroa mites and prevent mold in hives. It is also found as a preservative in halothane anesthetics.

Thymol’s strong but non-persistent profile makes it suitable for use as a natural pesticide, particularly in organic agriculture.

Regulatory & Safety Overview

• IFRA: No specific restrictions at typical usage levels

• EU Allergens: Trace presence in natural thyme oils; not directly listed

• FEMA GRAS: FEMA 3066 — approved for flavor use

• ECHA Classification: Not classified as hazardous under CLP

• Toxicology:

  • ~5× less toxic than phenol

  • Demonstrates low sensitization and phototoxicity

  • Biodegradable and non-accumulative

✅ Considered safe across perfumery, oral care, and food applications when used under recommended concentrations.

Natural Occurrence

Thymol is a naturally occurring compound in various members of the Lamiaceae family, including:

• Thymus vulgaris, T. zygis, T. glandulosus, T. hyemalis

• Origanum vulgare, O. compactum, O. dictamnus

• Monarda fistulosa, M. didyma

• Euphrasia rostkoviana, Trachyspermum ammi

Production Methods

Thymol can be produced by:

• Alkylation of p-cresol, followed by sulfonation and isopropylation

• Dehydrogenation of piperitone, yielding both menthol and thymol

• Oxidation of p-cymene, a natural component of turpentine

• Minor isolation from Ajowan oil (traditional Indian method)

Additional Information

Despite its "phenolic" label, Thymol's odor is cleaner, less aggressive, and far more floral-herbal than most simple phenols. It’s precisely this character—both medicinal and agrestic—that allows it to bridge clinical and aromaticterritory.

With growing interest in natural and functional fragrances, Thymol is once again gaining relevance—not only for its distinct scent but also for its pharmacological versatility and proven antimicrobial action in modern formulations.

Sources

• Fulvio Ciccolo — Internal Archive, 2023

• Steffen Arctander – Perfume and Flavor Chemicals

• NCBI PubChem CID 6989 – Thymol

• FEMA GRAS Database #3066