N/A — synthetic (also found naturally in Styrax tonkinensis, Castoreum)
Appearance
Colorless to pale yellow oily liquid; crystallizes below 20 °C
Odor Strength
high ,recommend smelling in a 1.00 % solution or less
Producing Countries
China, India, Germany, United States
Pyramid
Top-Heart
Marzipan left in a warm tin. Acetophenone has the almond-cherry sweetness of benzaldehyde but rounder, less volatile, with a hawthorn-floral undertone that drifts toward mimosa.
Sweet, almond-kernel, with a powdery hawthorn-floral quality absent from benzaldehyde. Less sharp, less volatile, more rounded. At low concentrati on, a waxy-narcotic quality surfaces — closer to the indolic sweetness of orange blossom than to cherry-pit sharpness. On blotter, the initial almond-marzipan note is prominent; after two hours, only a warm, clean, faintly powdery residue remains. Substantivity is moderate: roughly 7 hours at 100% on a strip.
Evolution over time
Immediately
Immediately
Bright almond-marzipan burst, sweet and slightly pungent. Cherry-pit sharpness but softer than benzaldehyde.
Clean, warm, faintly sweet residue. Very quiet. Moderate tenacity — essentially gone after 7-8 hours on blotter.
The Full Story
CAS 98-86-2. Molecular weight 120.15. The simplest aromatic ketone: one benzene ring, one acetyl group. Colourless crystals below 20°C; a pale yellow oily liquid above. Over 90% of commercial acetophenone is not manufactured on purpose — it forms as a byproduct of the cumene-to-phenol process (Hock rearrangement), where a methyl group migrates instead of the expected phenyl group. The remainder comes from Friedel-Crafts acylation of benzene or catalytic oxidation of ethylbenzene.
The smell sits in the almond-cherry corridor occupied by benzaldehyde, but acetophenone is softer. Less cyanide-sharp, more powdery. At dilution (below 1%), a hawthorn-floral quality emerges — closer to mimosa absolute than to almond extract. There is also a faint waxy-narcotic undertone, almost orange-blossom, that makes it useful in white-floral bases where a touch of edible sweetness is wanted without going fully gourmand.
Acetophenone occurs naturally in castoreum (beaver castor sacs), in Styrax tonkinensis resin, and in trace amounts in cherry, apricot, cranberry, roasted beef, and cocoa (up to 463 ppm in cocoa). Several essential oils under current EU regulatory pressure — labdanum absolute, benzoin resinoid, cassie flower absolute, ylang-ylang, cinnamon bark — contain acetophenone as a natural constituent.
Regulatory note: ECHA's Risk Assessment Committee (RAC) classified acetophenone as Repr. 1B (H360FD) in March 2025. The European Federation of Essential Oils (EFEO) submitted a derogation dossier to the SCCS (mandate issued October 2025) to defend its continued use in cosmetics as a constituent of natural complex substances. The outcome remains pending as of March 2026. TGSC lists maximum fragrance usage at 2.0% in concentrate.
In 2013, Brian Dias and Kerry Ressler at Emory University conditioned male mice to fear the smell of acetophenone by pairing it with mild footshocks. Their offspring — and their offspring's offspring — showed heightened sensitivity to acetophenone and enlarged olfactory glomeruli for the Olfr151 receptor, despite never encountering the molecule. The finding, published in Nature Neuroscience, provided the first evidence that a specific learned olfactory fear could be transmitted across generations through epigenetic changes in sperm DNA (CpG hypomethylation of the Olfr151 gene).
Extraction & Chemistry
Extraction method: Not extracted from natural sources commercially. Over 90% of global acetophenone production is a byproduct of the Hock process (cumene oxidation to phenol and acetone), where an alternate rearrangement of isopropylbenzene hydroperoxide yields acetophenone and methanol instead of the expected phenol and acetone. The remainder is produced via Friedel-Crafts acylation of benzene with acetyl chloride (AlCl3 catalyst) or by catalytic oxidation of ethylbenzene at 141-148°C and 3 atm. Commercial purity: 98-100%. Inexpensive, bulk-scale production. Melting point 19-20°C means it crystallises in cool storage and must be gently warmed before use.
Molecular Formula
C8H8O
CAS Number
98-86-2
Botanical Name
N/A — synthetic (also found naturally in Styrax tonkinensis, Castoreum)
IFRA Status
Restricted — max 2.0% in fragrance concentrate (TGSC). ECHA RAC classified Repr. 1B (H360FD) in March 2025. SCCS safety assessment pending (mandate issued October 2025). EFEO derogation dossier submitted for continued use as NCS constituent.
Synonyms
METHYL PHENYL KETONE · ACETYLBENZENE
Physical Properties
Odor Strength
high ,recommend smelling in a 1.00 % solution or less
Lasting Power
7 hour(s) at 100.00 %
Appearance
Colorless to pale yellow oily liquid; crystallizes below 20 °C
Boiling Point
202.00 to 203.00 °C. @ 760.00 mm Hg
Flash Point
179.00 °F. TCC ( 81.67 °C. )
Specific Gravity
1.02500 to 1.03200 @ 25.00 °C.
Refractive Index
1.53300 to 1.53600 @ 20.00 °C.
Melting Point
19.00 to 20.00 °C. @ 760.00 mm Hg
In Perfumery
Modifier in almond, cherry-blossom, and hawthorn accords. Acetophenone delivers a softer, more floral versi on of the almond character that benzaldehyde provides — less cyanide-sharp, more powdery. It functions in the top-to-heart zone (boiling point 202°C, substantivity 7 hours), bridging fruity-sweet openings into floral hearts. In cherry-blossom bases, it rounds out the benzaldehyde core. In hawthorn reconstructions, it is nearly indispensable. It also is a sweet modifier in white-floral and mimos a compositions, contributing a narcotic-edible quality at low dosages (typically below 1% in concentrate). In gourm and ambers, small additions enhance marzipan and noug at effects. The molecule is also a precurs or in synthes is: starting material for methyl styryl ketone and various chalcones used in fragrance chemistry. FEMA 2009.
