Warm, sweet, unmistakably powdery — the smell of a closed cosmetics drawer. Musk ketone has the thick, rounded sweetness of face powder pressed into a gold compact: softer than musk xylene, denser than any macrocyclic musk, and carrying a faint nitro-chemical edge beneath the velvet.
Fat, sweet, powdery musk with a warm cosmetic character — face powder, soaped skin, the inside of a vintage leather handbag. Denser and more opaque than Galaxolide, which reads cleaner and more transparent. Sweeter and less animalic than muscone. Lacks the blackberry-fruity quality of Galaxolide and the lactonic softness of ethylene brassylate. A faint chemical-nitro edge sits underneath, detectable on blotter but masked in composition. Medium diffusion, notable tenacity.
Evolution over time
Immediately
Immediately
Sweet, dense, powdery musk. Warm cosmetic quality — face powder, soaped skin. A faint chemical-nitro undertone.
After a few hours
After a few hours
The nitro edge fades. Stable, rounded musky heart. Thick powdery sweetness persists with little evolution. Golden, warm, opaque.
After a few days
After a few days
Slow, gradual fade. Powdery musky residue remains perceptible for days. The sweetness compresses but does not vanish. Exceptional tenacity on fabric.
The Full Story
CAS 81-14-1. Molecular formula C₁₄H₁₈N₂O₅, molecular weight 294.31. A nitro musk — one of the oldest class of synthetic musks. Albert Baur developed musk ketone in 1894, six years after his accidental discovery of the first nitro musk (Musk Baur) during Friedel–Crafts alkylation experiments on toluene derivatives. The IUPAC name is 1-(4-tert-butyl-2,6-dimethyl-3,5-dinitrophenyl)ethanone. It arrives as a yellow crystalline powder, melting at 135–139 °C.
The scent is fat, sweet, powdery-musky — a warm, cosmetic sweetness that defined the musk accord in fine perfumery from the 1920s through the 1970s. It is denser and more opaque than polycyclic musks like Galaxolide, which tend toward a cleaner, more transparent profile. Compared to macrocyclic musks such as muscone or ethylene brassylate, musk ketone is markedly sweeter, more powdery, and less animalic. It lacks the lactonic softness of ethylene brassylate and the fur-like character of muscone. Its substantivity is notable: 400 hours at 20% in dipropylene glycol on blotter.
Nitro musks have been increasingly restricted. Musk ketone is lipophilic and bioaccumulates in human adipose tissue and breast milk, at concentrations of 0.01–0.22 mg/kg fat. The EU Cosmetics Regulation limits musk ketone to 1.4% in fine fragrance, 0.56% in eau de toilette, and 0.042% in other leave-on products. IFRA mandates that commercial musk ketone must contain less than 0.1% musk xylene as impurity. Production has declined sharply; the material is being phased out in favor of macrocyclic musks (ethylene brassylate, Exaltolide, Habanolide) and polycyclic musks (Galaxolide, Tonalide), though no single replacement replicates its particular opaque sweetness.
Musk ketone bioaccumulates in human fat tissue. A 1994 study published in Chemosphere measured nitro musk concentrations in human adipose tissue and breast milk across Germany, finding musk ketone residues in nearly every sample — at levels of 0.01 to 0.22 mg per kilogram of fat. The compound’s lipophilicity (logP ≈ 2.5) means it partitions readily into fatty tissue and is eliminated only slowly.
Extraction & Chemistry
Extraction method: Fully synthetic. Produced by Friedel–Crafts acylation of 1-tert-butyl-3,5-dimethylbenzene, followed by dinitration with mixed acid (HNO₃/H₂SO₄). The nitration step requires careful temperature control due to the exothermic nature and the presence of nitro groups on the aromatic ring. The product crystallizes as a yellow powder. Commercial grades must contain less than 0.1% musk xylene impurity (IFRA specification). Global production has declined significantly since the 1990s due to regulatory pressure and environmental concerns about bioaccumulation.
Molecular Formula
C14H18N2O5
CAS Number
81-14-1
Botanical Name
N/A — synthetic nitro-musk
IFRA Status
IFRA Specification: must contain less than 0.1% musk xylene. EU restricted — max 1.4% in fine fragrance, 0.56% in eau de toilette, 0.042% in other leave-on products.
Base note and fixative in classic and vintage-style compositions. Musk ketone provides the warm, opaque, powdery-musky foundation that defined 20th-century perfumery — particularly in floral-aldehyde and amber families. It functions as a volume builder and blender, rounding sharp edges in a composition while adding a thick, sweet musky trail. Its use is now constrained by EU regulation (maximum 1.4% in fine fragrance) and declining availability. Modern replacements include ethylene brassylate (softer, more lactonic), Galaxolide (cleaner, more transparent), Exaltolide (creamy, delicate), and Habanolide (metallic-musky). None fully replicate musk ketone’s particular dense, powdery opacity. In compositions where a skin-like, powdery musk accord is central, musk ketone remains difficult to substitute. Its fixative power is significant — the molecule’s low vapor pressure (0.000012 mmHg at 25 °C) keeps it anchored in the dry-down for days.
