In short
p-Cymene is an aromatic monoterpene found in thyme, cumin and aged citrus oils. It has a citrusy, herbal odour with a slightly solvent-like edge.
What p-Cymene smells like
p-Cymene is a citrus-terpenic aromatic with a woody, somewhat harsh character. The Good Scents Company, at 1%, lists fresh, citrus, terpene, woody and spice, and its own evaluation calls it harsh, chemical, woody and terpy with an oxidised-citrus lemon note. Grades differ: Arctander describes a highly purified grade as sweet, soft and fresh, with lemon and bergamot top notes, while one supplier lists terpenic, harsh and coniferous. It is volatile and short-lived.
- Leading note
- Harsh citrus-terpenic
- Clear facets
- Woody
- Supporting facets
- Oxidised lemon, solvent-like
- Faint facets
- Spice
- Character
- Harsh, dry, terpenic, volatile
What makes p-Cymene distinctive
Its harshness. Where limonene and gamma-terpinene are fresh, p-cymene reads as citrus that has turned — woody, solvent-like, with an oxidised lemon note — unless it is highly purified.
Where the descriptions disagree: Arctander describes a purified grade as sweet and soft with lemon and bergamot; technical grades are described as harsh, woody and terpenic.
How p-Cymene is used
Used to give volume and warmth to citrus, aromatic and woody accords, and widely to scent soaps, detergents and household goods and to mask industrial odours.
Typical role: modifier (used in small amounts to change the character of a blend).
How p-Cymene differs from similar materials
- gamma-Terpinene
- Gamma-terpinene is fresher, lime- and thyme-like; p-cymene is harsher, woodier and solvent-like.
Each difference compares the published descriptions of the two materials. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Formulation considerations
Rising p-cymene in a citrus oil is a sign that it has aged.
Identity and classification
- Type
- Aroma chemical
- Origin
- Occurs in nature
- Odour family
- Citrus / Aromatic
- Note position
- Top note
- Physical form at room temperature
- Liquid
- Also known as
- 4-Isopropyltoluene
- CAS number
- 99-87-6
- Molecular formula
- C10H14
- Molecular weight
- 134.22 g/mol
- IUPAC name
- 1-methyl-4-propan-2-ylbenzene
The CAS number, formula and molecular weight are taken from PubChem compound 7463, 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. It has a harmonised EU classification (Regulation (EC) No 1272/2008, Annex VI): H226 flammable liquid and vapor; H304 may be fatal if swallowed and enters airways; H331 toxic if inhaled; H411 toxic to aquatic life with long lasting effects. Companies notifying the ECHA C&L Inventory classify it (2,209 reports): H226 flammable liquid and vapor (99.7% of reports); H304 may be fatal if swallowed and enters airways (96.5% of reports); H411 toxic to aquatic life with long lasting effects (93.5% of reports); H315 causes skin irritation (15.7% of reports); H319 causes serious eye irritation (10.7% of reports). 1 of the reports find it does not meet the hazard criteria. 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
-
Thymol
Aroma chemical · Aromatic / Spicy — thyme, medicinal, herbal, phenolic
-
Carvacrol
Aroma chemical · Aromatic / Spicy — oregano, phenolic, herbal, spicy
-
gamma-Terpinene
Aroma chemical · Citrus / Aromatic — citrus, herbal, oily, lime
-
Cumin Seed Oil
Essential oil · Spicy / Animalic — spicy, animalic, sweaty, warm
Used in formulas and accords
Used in 1 published formula
p-Cymene is an ingredient in 1 perfume formula in the Formula & Accord Library.
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about p-Cymene
Is p-Cymene natural or synthetic?
The molecule occurs in nature. Commercial p-Cymene 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 p-Cymene?
99-87-6. It was checked against PubChem on 19 October 2026.
Which published formulas use p-Cymene?
p-Cymene is used in 1 published formula in the RUŌOD Lab Formula & Accord Library: Asphalt Peony. Each is listed with a link under "Used in formulas and accords" on this page.
Sources
- PubChem — compound 7463, checked 19 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- The Good Scents Company — p-cymene — odour database.
- Parchem — para-cymene — distributor's description.
- Taylor & Francis — p-cymene (contact allergy monograph extract) — published literature.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 20 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.