Mefranal

What Mefranal smells like

Mefranal (Givaudan; 3-methyl-5-phenylpentanal) is a citrus-aldehydic floral with a geranium character. The Good Scents Company lists citrus, aldehydic and geranium for Givaudan's material, and citrus, aldehydic, floral and green generally; a distributor describes lemon-geranium brightness, an aldehydic floral heart with lily-of-the-valley nuances and strong tenacity, and Vigon gives aldehydic and lily of the valley. Its alcohol, Mefrosol, is a different material.

Leading note

Lemon-geranium aldehydic

Supporting facets

Lily of the valley, green

Faint facets

Rosy

Character

Bright, fresh, aldehydic, tenacious

• aldehydic
• citrus
• geranium
• floral

What makes Mefranal distinctive

Lemon and geranium in an aldehyde — a bright, citrus-floral top that lasts much longer than a citrus aldehyde would.

How Mefranal is used

Used for bright, citrus-geranium and fresh floral effects in floral and fresh compositions.

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

How Mefranal differs from similar materials

Peonile

Peonile is a non-volatile rose-geranium nitrile with a green-citrus facet; Mefranal is brighter and more aldehydic, lemon-geranium with muguet.

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.

Identity and classification

Type

Aroma chemical

Origin

Synthetic

Odour family

Floral / Green

Note position

Heart note

Physical form at room temperature

Liquid

Also known as

3-Methyl-5-phenylpentanal

CAS number

55066-49-4

Molecular formula

C12H16O

Molecular weight

176.25 g/mol

IUPAC name

3-methyl-5-phenylpentanal

The CAS number, formula and molecular weight are taken from PubChem compound 108313, 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): H302 harmful if swallowed; H315 causes skin irritation; H317 may cause an allergic skin reaction; H411 toxic to aquatic life with long lasting effects. Companies notifying the ECHA C&L Inventory classify it (1,550 reports): H302 harmful if swallowed (100% of reports); H315 causes skin irritation (100% of reports); H317 may cause an allergic skin reaction (100% of reports); H411 toxic to aquatic life with long lasting effects (100% of reports); H319 causes serious eye irritation (25.1% 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

• Phenylethyl Alcohol

  Aroma chemical · Floral / Green — rose, honeyed, soft, floral

• Citronellol

  Aroma chemical · Floral / Green — rosy, fresh, citrus, waxy

• Geraniol

  Aroma chemical · Floral / Citrus — rosy, sweet, citrus, fresh

• Rose Oxide

  Aroma chemical · Floral / Metallic — metallic, green, geranium, rosy

Used in formulas and accords

Not currently used in any published formula.

The Formula & Accord Library lists Mefranal here as soon as a published formula, accord or base uses it.

Further reading

• How to Make a Rose Accord

  Build a rose accord from phenylethyl alcohol, citronellol and geraniol, add acetates and powerful traces from dilutions, and balance it by ratio trials.

• Perfume Materials by Odor Family: A Formulator's Palette Map

  Which materials build each odor family — citrus, floral, woody, amber, musk and more — their usual roles, what to watch for, and links to each in depth.

Questions about Mefranal

Sources

• PubChem — compound 108313, 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 — 3-methyl-5-phenylpentanal (Mefranal) — odour database.
• Fraterworks — Mefranal — distributor's description.
• ChemicalBook — 3-methyl-5-phenylpentanal (CAS 55066-49-4) — odour database.
• 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 2. Descriptions of odour are judgement, not measurement.