Phenylacetic Acid

What Phenylacetic Acid smells like

Phenylacetic acid has a sweet, animal, honey-like odour in dilute solution that becomes persistent and disagreeable when concentrated, in ChemicalBook's description. Perfumery glossaries describe it as warm and golden at proper dilution, with a faintly urinous, barnyard edge at higher levels, and as a more naturalistic honey than synthetic 'honey' molecules. It is a volatile component of honey and also occurs in rose and narcissus. A 1980s patent notes its animal note can be too pronounced to harmonise.

Leading note

Animalic honey

Clear facets

Sweet

Supporting facets

Urinous, barnyard

Faint facets

Waxy

Character

Warm, heavy, animalic, persistent

• honey
• animalic
• sweet
• waxy

What makes Phenylacetic Acid distinctive

Honey as it really smells: golden and sweet, with the faintly urinous, animal undertone that makes natural honey more than sugar.

Concentration and dilution

Warm, golden honey at proper dilution; urinous and disagreeable at concentration.

How Phenylacetic Acid is used

Used in small amounts as a honey modifier and in animalic bases, and in rose, narcissus and tobacco compositions.

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

How Phenylacetic Acid differs from similar materials

Methyl Phenylacetate

The methyl ester is a lighter, brighter honey with jasmine; the acid is heavier, waxier and more animalic.

p-Cresyl Phenylacetate

p-Cresyl phenylacetate pairs honey with narcissus and leather; the acid is honey with a urinous edge, without the floral narcotic note.

Ethyl Phenylacetate

Ethyl phenylacetate is a sweet floral honey with rose and fruit; the acid is heavier and animalic.

Linden Blossom Absolute

Linden is a green, citrus-tea honey with a soft hay drydown; phenylacetic acid is heavy, animalic honey.

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

A solid acid; dissolve before use and dose from dilution. It can react with alcohols over time to form esters.

Identity and classification

Type

Aroma chemical

Origin

Occurs in nature

Odour family

Animalic / Gourmand

Note position

Base note

Physical form at room temperature

Solid

CAS number

103-82-2

Molecular formula

C8H8O2

Molecular weight

136.15 g/mol

IUPAC name

2-phenylacetic acid

The CAS number, formula and molecular weight are taken from PubChem compound 999, 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 (1,864 reports): H319 causes serious eye irritation (85.5% of reports); H318 causes serious eye damage (14.4% 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

• Ethyl Phenylacetate

  Aroma chemical · Gourmand / Floral — honey, sweet, floral, fruity

• Phenylethyl Phenylacetate

  Aroma chemical · Floral / Gourmand — honey, rose, balsamic

• beta-Damascenone

  Aroma chemical · Fruity / Floral — fruity, cooked apple, plum, rose

Phenylacetic Acid is also suggested as a partner on the pages for Allyl Phenoxyacetate, Isobutyl Phenylacetate, Methyl Phenylacetate, p-Cresyl Phenylacetate and Phenylethyl Acetate.

Used in formulas and accords

Used in 9 published formulas

Phenylacetic Acid is an ingredient in 5 perfume formulas and 4 accords in the Formula & Accord Library.

Community formulas

• Dried Fruits Accord

  Community Formula · Accord · listed as “Phenyl Acetic Acid 10%”, at 10%

• Honeyed Rose Accord

  Community Formula · Accord · listed as “Phenyl Acetic Acid”

• Tamarind Accord

  Community Formula · Accord · listed as “Phenyl Acetic Acid 40%”, at 40%

• Tobacco Accord

  Community Formula · Accord · listed as “Phenyl Acetic Acid 10%”, at 10%

RUŌOD House Originals

Original compositions by RUŌOD House.

• Beeswax Throne

  RUŌOD House Creation · listed as “Phenylacetic Acid 10% DPG”, at 10% in DPG

• Cured Leaf

  RUŌOD House Original · listed as “Phenylacetic Acid 10% DPG”, at 10% in DPG

• Pipe Smoke Orchard

  RUŌOD House Creation · listed as “Phenylacetic Acid 10% DPG”, at 10% in DPG

• Salt Lantern

  RUŌOD House Creation · listed as “Phenylacetic Acid 10% DPG”, at 10% in DPG

• Skin Heat

  RUŌOD House Creation · listed as “Phenylacetic Acid 10% DPG”, at 10% in DPG

Further reading

• How to Build a Honey Accord

  A honey accord from phenylacetic acid and its esters: the building blocks, beeswax and honey absolutes, an illustrative vegan version, handling and records.

• Animalic Notes in Perfumery: From Civet to Synthetics

  The classic animal materials — musk, civet, castoreum, ambergris — why they went, and how indole, skatole and synthetic bases recreate animalic warmth.

Questions about Phenylacetic Acid

Sources

• PubChem — compound 999, checked 19 October 2026.
• PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
• ChemicalBook — phenylacetic acid (CAS 103-82-2) — odour database.
• Premiere Peau — Phenyl acetic acid — published perfumery reference.
• US4584127 — Utilization of 1-cyclopentenylacetic acid as perfuming ingredient (patent) — 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.