Methyl Heptine Carbonate

What Methyl Heptine Carbonate smells like

Methyl heptine carbonate (methyl 2-octynoate) is a very powerful green material with the smell of violet leaves and fresh vegetables. Bedoukian describes it as green, violet, vegetable and hay-like — a very powerful, outdoor, violet-foliage and fresh green-vegetable odour — and Givaudan notes violet-leaf and cucumber notes when it is used in traces. A Parchem specification adds fatty, waxy, cucumber and melon. Concentrated, it is powerful and unpleasant; on dilution it becomes violet-like. It is one of the 26 fragrance allergens individually named in EU cosmetics law.

Leading note

Violet leaf

Clear facets

Fresh green vegetable

Supporting facets

Cucumber, hay-like

Faint facets

Fatty, waxy

Character

Green, powerful, raw, fatty

• green
• violet leaf
• cucumber
• fatty

What makes Methyl Heptine Carbonate distinctive

It is the raw, vegetal violet leaf — powerful, outdoorsy and hay-tinged — where its higher homologue, methyl octine carbonate, is softer and more floral.

Concentration and dilution

Powerful and unpleasant when concentrated; violet-like only on dilution. It is used in traces.

How Methyl Heptine Carbonate is used

Used in traces for violet-leaf, green and cucumber effects in fresh, green and violet compositions — the classic synthetic violet-leaf note before the nonadienals became common.

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

How Methyl Heptine Carbonate differs from similar materials

Methyl Octine Carbonate

Methyl octine carbonate is softer and more floral, with a mimosa-like delicacy; methyl heptine carbonate is the more powerful, vegetal and hay-like of the two.

2,6-Nonadienal

Nonadienal is cucumber first, then violet leaf, and more aggressively fatty-green; methyl heptine carbonate is violet foliage first, with a vegetable, hay-like character.

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

Extremely strong; dose from a high dilution. A declarable allergen covered by an IFRA Standard.

Identity and classification

Type

Aroma chemical

Origin

Synthetic

Odour family

Green / Aquatic

Note position

Top note

Physical form at room temperature

Liquid

Also known as

Methyl 2-octynoate

CAS number

111-12-6

Molecular formula

C9H14O2

Molecular weight

154.21 g/mol

IUPAC name

methyl oct-2-ynoate

The CAS number, formula and molecular weight are taken from PubChem compound 8092, whose own record lists this CAS number; checked 19 October 2026.

Safety and compliance

The IFRA Standards Library lists a Standard covering Methyl Heptine Carbonate:

• "Methyl heptine carbonate" — Restriction, 49th Amendment, published 2020-01

Limits differ by product category and are set out in the Standard itself; this page does not reproduce them. The list above reflects the library as read on 19 October 2026.

Methyl Heptine Carbonate is one of the 26 fragrance allergens listed individually in Annex III of the EU Cosmetics Regulation (label name: Methyl 2-octynoate), which must be named on cosmetic labels above 0.001% in leave-on and 0.01% in rinse-off products. Regulation (EU) 2023/1545 extended the list; see the fragrance allergens list.

Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (1,763 reports): H317 may cause an allergic skin reaction (97.4% of reports); H302 harmful if swallowed (97.3% 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

• Violet Leaf Absolute

  Absolute · Green / Aquatic — green, leafy, cucumber, watery

• 2,6-Nonadienal

  Aroma chemical · Green / Aquatic — cucumber, green, violet leaf, watery

• alpha-Ionone

  Aroma chemical · Powdery / Fruity — violet, powdery, fruity, sweet

• Methyl Octine Carbonate

  Aroma chemical · Green / Aquatic — violet leaf, green, cucumber, fatty

Methyl Heptine Carbonate is also suggested as a partner on the pages for Koavone and Undecavertol.

Used in formulas and accords

Used in 2 published formulas

Methyl Heptine Carbonate is an ingredient in 1 perfume formula and 1 accord in the Formula & Accord Library.

Community formulas

• Pumpkin Accord

  Community Formula · Accord

RUŌOD House Originals

Original compositions by RUŌOD House.

• Tuberose Under Neon

  RUŌOD House Original · listed as “Methyl Heptine Carbonate 1% DPG”, at 1% in DPG

Further reading

• Green Notes in Perfumery: Leaf, Galbanum and Violet Leaf

  The green palette — cis-3-hexenol, galbanum, violet leaf, styrallyl acetate — what green notes do, dosage, restrictions and pairings.

• The Fragrance Allergens List: The 26, the Expanded EU List and Their Sources

  The 26 EU-listed fragrance allergens, where each typically occurs, the two now prohibited, the expanded 2023/1545 list, and other markets.

Questions about Methyl Heptine Carbonate

Sources

• PubChem — compound 8092, checked 19 October 2026.
• PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
• IFRA — Standards Library, read 19 October 2026.
• EUR-Lex — Regulation (EC) No 1223/2009, Annex III.
• The Good Scents Company — methyl 2-octynoate (with Bedoukian and Givaudan descriptions) — odour database.
• Parchem — methyl heptine carbonate specification — distributor's description.
• ChemicalBook — methyl 2-octynoate (CAS 111-12-6) — odour database.
• Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 20 October 2026. Evidence: several independent published descriptions, which agree. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.