Terpinen-4-ol

In short

Terpinen-4-ol is a monoterpene alcohol and the main constituent of tea tree oil. It also occurs in marjoram and juniper and has a warm, spicy-herbal odour.

What Terpinen-4-ol smells like

Terpinen-4-ol is the main constituent of tea tree oil and of sweet marjoram oil. A supplier describes it as a pale yellow liquid with a mild earthy, woody odour, with fresh herbaceous, camphoraceous and medicinal nuances; a chemical database lists peppery, spicy, musty and citrus.

Leading note: Earthy woody-herbal
Supporting facets: Peppery, spicy, camphoraceous, medicinal
Faint facets: Musty, citrus
Character: Mild, earthy, warm

What makes Terpinen-4-ol distinctive

A milder, earthier, more peppery note than the oils it dominates.

How Terpinen-4-ol is used

Used in herbal, spicy and woody compositions and in tea tree and marjoram reconstructions.

Typical role: modifier (used in small amounts to change the character of a blend).

How Terpinen-4-ol differs from similar materials

Tea Tree Oil: Tea tree oil adds camphor, cineole and a fresh, forest-like note to terpinen-4-ol's earthy, peppery woodiness. (compared directly by a cited source)
Sweet Marjoram Oil: Sweet marjoram is also terpinen-4-ol-led, adding a warm, sweet-spicy, cardamom-like herb. (compared directly by a cited source)

An asterisk marks a difference that a cited source states directly. The others compare the published descriptions of each material. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.

Identity and classification

Type: Aroma chemical
Origin: Occurs in nature
Odour family: Aromatic / Spicy
Note position: Top to heart note
Physical form at room temperature: Liquid
Also known as: 4-Terpinenol, 4-Methyl-1-(propan-2-yl)cyclohex-3-en-1-ol
CAS number: 562-74-3
Molecular formula: C10H18O
Molecular weight: 154.25 g/mol
IUPAC name: 4-methyl-1-propan-2-ylcyclohex-3-en-1-ol

The CAS number, formula and molecular weight are taken from PubChem compound 11230, whose own record lists this CAS number; checked 19 October 2026.

Safety and compliance

Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (2,000 reports): H315 causes skin irritation (98.5% of reports); H319 causes serious eye irritation (96.6% of reports); H336 may cause drowsiness or dizziness (14.5% of reports); H317 may cause an allergic skin reaction (13.1% of reports). A skin sensitiser classification concerns handling the neat material and the dose in a finished product; the IFRA Standards, where they apply, set the limits. Unless it is harmonised, this is the notifiers' own classification, not a binding one.

This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.

Materials it works with

Tea Tree Oil
Essential oil · Aromatic / Spicy — medicinal, herbal, spicy, woody
alpha-Terpineol
Aroma chemical · Floral / Aromatic — lilac, floral, piney, herbal
Sweet Marjoram Oil
Essential oil · Aromatic / Spicy — herbal, warm, spicy, woody
Nutmeg Oil
Essential oil · Spicy / Woody — spicy, warm, woody, sweet

Terpinen-4-ol is also suggested as a partner on the pages for p-Tolylacetaldehyde, Sabinene and Terpinolene.

Used in formulas and accords

Used in 1 published formula

Terpinen-4-ol is an ingredient in 1 accord in the Formula & Accord Library.

Pumpkin Accord
Community Formula · Accord · listed as “Terpinen-4-Ol”

Questions about Terpinen-4-ol

Is Terpinen-4-ol natural or synthetic?

The molecule occurs in nature. Commercial Terpinen-4-ol may be made by synthesis or obtained from natural sources, so check the supplier's specification if the distinction matters to you.

What is the CAS number of Terpinen-4-ol?

562-74-3. It was checked against PubChem on 19 October 2026.

Which published formulas use Terpinen-4-ol?

Terpinen-4-ol is used in 1 published formula in the RUŌOD Lab Formula & Accord Library: Pumpkin Accord. Each is listed with a link under "Used in formulas and accords" on this page.

Sources

PubChem — compound 11230, checked 19 October 2026.
PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
Foreverest — Terpinen-4-ol — manufacturer's description.
Cannabis Compound Database — terpinen-4-ol — odour database.
Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 21 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.