Warm, floury sweetness — like ironing cotton bedsheets with a trace of vanilla. Barely perceptible up close, yet it outlasts nearly every material in the perfumer’s palette, lingering on fabric for over 200 hours.
Almost inaudible in the opening — a faint, floury sweetness that registers as warmth rather than scent. Softer and rounder than Galaxolide (which carries a metallic, soapy edge), warmer than Habanolide (which tends waxy and woody), and less animalic than Exaltolide (which retains a closer kinship to natural muscone). The two ester bonds give ethylene brassylate a lactonic sweetness — a hint of vanilla seed, of freshly ironed linen — that macrocyclic ketones lack.
On skin, it reads as a clean, intimate murmur rather than a declared note. After several hours it develops a faint ambrette-seed quality, dry and textile, persisting long after sharper materials have evaporated.
Evolution over time
Immediately
Immediately
Near-silent. A faint floury warmth, almost subliminal — like the residual scent of freshly laundered cotton before any detergent fragrance develops. No sharp attack, no discernible top-note character.
After a few hours
After a few hours
The lactonic sweetness emerges: faintly vanillic, faintly waxy, with a textile warmth that clings to skin. A suggestion of ambrette seed. Still quiet, but now identifiable as musk. This is where ethylene brassylate begins to function as a fixative, holding lighter materials in place.
After a few days
After a few days
On fabric, the molecule persists as a clean, dry, powdery warmth — no longer identifiable as a discrete note but present as a diffuse halo of laundered warmth. On blotter, detectable past 200 hours. The final trace is purely textural: soft, warm, faintly sweet.
The Full Story
Ethylene brassylate (CAS 105-95-3, IUPAC: 1,4-dioxacycloheptadecane-5,17-dione) is a 17-membered macrocyclic dilactone with molecular weight 270.37 g/mol. It belongs to the macrocyclic musk family — structurally distinct from nitro musks (now largely banned), polycyclic musks like Galaxolide, and the macrocyclic ketones (muscone, civetone) that Leopold Ruzicka synthesised in the 1920s. Its two ester linkages within the ring give it a sweeter, more powdery character than ketone-type macrocyclics. At room temperature it is a colourless to pale yellow oily liquid (mp −8 °C, bp 138–142 °C at 1 mmHg, d 1.042 g/mL at 25 °C).
Smelled on blotter, it opens with almost nothing — a whisper of warm laundry, a dusting of flour. There is no sharp attack, no projection to speak of. It sits close, like body heat trapped under a collar. Over hours the sweetness deepens: faintly vanillic, faintly waxy, with a textile warmth that reads as clean skin rather than perfume. Its substantivity exceeds 200 hours on blotter at full concentration, making it one of the most persistent materials available to perfumers.
The molecule was first synthesised in 1933–1934 at DuPont in the United States by cyclising brassylic acid (1,13-tridecanedioic acid) with ethylene glycol under macrolactonisation conditions. Brassylic acid itself is obtained industrially by ozonolysis of erucic acid, a C22 monounsaturated fatty acid abundant in rapeseed and mustard seed oil. DuPont marketed it under the trade names Musk T and Astrotone. Its debut in fine perfumery came almost immediately: around 1934, André Fraysse incorporated ethylene brassylate into the base of Arpège (1927), reinforcing the powdery, musky drydown of that aldehydic floral.
Ethylene brassylate spread rapidly through the industry because it was a liquid (easy to weigh and blend), cheap to produce from renewable feedstock, and compatible with virtually every fragrance family. Unlike polycyclic musks, it biodegrades readily and is not classified as a PBT (persistent, bioaccumulative, toxic) substance. IFRA imposes no quantitative restriction — it is permitted at up to 100% in all product categories under the 51st Amendment (July 2023). It carries FEMA GRAS status (FEMA 3543) for food flavouring at trace levels.
Ethylene brassylate was DuPont’s entry into the fragrance industry. Within months of its 1934 synthesis, perfumer André Fraysse added it to the base of Arpège (1927), making that aldehydic floral the first fine fragrance to showcase a macrocyclic dilactone musk — and proving that synthetic musks could hold their own alongside the civetone and muscone bases that had defined luxury perfumery until then.
Extraction & Chemistry
Extraction method: Fully synthetic. Produced by macrolactonisation: brassylic acid (1,13-tridecanedioic acid, CAS 505-52-2) is cyclised with ethylene glycol under acid catalysis and high-dilution conditions to form the 17-membered ring dilactone. Brassylic acid is obtained industrially by ozonolysis of erucic acid (CAS 112-86-7), a C22 monounsaturated fatty acid from rapeseed or mustard seed oil. The ozonolysis cleaves the C13=C14 double bond, yielding brassylic acid (C13) and pelargonic acid (C9, a by-product used in plasticisers and herbicides). Final product purity is typically >95% by GC.
Molecular Formula
C₁₅H₂₆O₄
CAS Number
105-95-3
Botanical Name
N/A (synthetic molecule)
IFRA Status
No restriction. Permitted at up to 100% in all IFRA product categories under the 51st Amendment (July 2023). Not listed among the 26 EU fragrance allergens requiring label declaration. FEMA GRAS status (FEMA 3543) for food use at trace levels. Readily biodegradable; not classified as PBT.
Synonyms
EB MUSK · MUSK T · ETHYLENE DODECANEDIOATE · BRASSYLATE
Physical Properties
Odor Strength
Medium
Lasting Power
208 hours
Appearance
colorless to pale yellow clear oily liquid
Boiling Point
138.00 to 142.00 °C. @ 1.00 mm Hg
Flash Point
> 212.00 °F. TCC ( > 100.00 °C. )
Specific Gravity
1.04000 to 1.04700 @ 25.00 °C.
Refractive Index
1.46800 to 1.47400 @ 20.00 °C.
In Perfumery
Ethylene brassylate is first and foremost a fixative. Its molecular weight (270.37) and extremely low vapour pressure keep it anchored to skin and fabric, slowing the evaporation of lighter materials layered above it. In practice, it extends the drydown of almost any composition without imposing its own character — it is a structural ingredient, not a signature note. It is indispensable in white musk accords, often blended with Galaxolide (for soapy projection), Habanolide (for woody powder), and Helvetolide (for clean pear-skin transparency). In floral compositions, it acts as a velvet lining beneath jasmine, rose, and tuberose, softening their edges without dulling them. In amber and gourmand accords, it reinforces vanilla and tonka bean without adding perceptible sweetness. Because it biodegrades readily and carries no IFRA restriction, it has increasingly replaced polycyclic musks in formulas intended for ecological certification. Its cost — low, due to industrial ozonolysis of rapeseed-derived erucic acid — makes it a common musk in both fine and functional perfumery.
