What is CAS 122-57-6 for 4-Phenylbut-3-en-2-one (Benzylideneacetone)?

CAS 122-57-6 is the unique numerical identifier assigned to 4-Phenylbut-3-en-2-one (Benzylideneacetone) by the Chemical Abstracts Service. It is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports.

Annex II Entry 356 20/10/2010

4-Phenylbut-3-en-2-one (Benzylideneacetone)

Q: How do I check if my product formula contains 4-Phenylbut-3-en-2-one (Benzylideneacetone)?

Use the INCI Checker tool on CosIng Checker to paste your full ingredient list and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records.

4-Phenylbut-3-en-2-one (Benzylideneacetone) is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

Search similar Back to annex Compare

Prohibited substance— Annex II, EU Regulation 1223/2009

Entry: 356

Chemical identity and properties

PubChem 2D chemical structure for CAS 122-57-6

CAS 122-57-6PubChem CID 15909

4-Phenyl-3-Buten-2-one

Benzylideneacetone is a flavouring ingredient. Benzylideneacetone is present in hydrolysed soy protein Benzylideneacetone belongs to the family of Phenylpropenes. These are compounds containing a phenylpropene moeity, which consists of a propene substituent bound to a phenyl group. — Toxin and Toxin Target Database (T3DB)

IUPAC name: 4-phenylbut-3-en-2-one

Molecular formula: C10H10O
Molecular weight: 146.19 g/mol
Exact mass: 146.073164938 Da
XLogP3: 2.1
Topological polar surface area: 17.1 Å²
Hydrogen-bond donors: 0
Hydrogen-bond acceptors: 1
Covalent units: 1
Defined stereocentres: 0

Also known as

RefChem:10714023-Buten-2-one, 4-phenyl-Methyl styryl ketone4-Phenyl-but-3-en-2-onebenzalacetone-d4acetylstyroltrans-Benzylideneacetone;BenzalacetoneBENZAL ACETONE

5 more reported names

1-Phenylbut-1-en-3-one4-phenyl-3 -buten-2-oneTrans-4-Phenyl-3-buten-2-one?NCI60_0043694-Phenyl-3-butene-2-one 100 microg/mL in Acetonitrile

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEMBL:CHEMBL3187978
EPA DTXSID:DTXSID4025662
PubMed:22899515
PubMed:22885048
PubMed:22701637
PubMed:22692228
PubMed:22655244
PubMed:22645592
PubMed:22259576
PubMed:22259575
PubMed:22231494
PubMed:22179573
PubMed:22170331
PubMed:22082189

Evidence from additional scientific databases

NIH PubChem PUG-View

Exact identifier match15909

Attributed physical-property, hazard, environmental and use annotations.

Boiling Point: 260 °C Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)

Physical Description: colourless to slightly yellow crystalline solid with a sweet, pungent, creamy, floral odour Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)

Solubility: insoluble in water; soluble in organic solvents, oils Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)
Solubility: very soluble (in ethanol) Source: Joint FAO/WHO Expert Committee on Food Additives (JECFA)

Carcinogen Classification: No indication of carcinogenicity to humans (not listed by IARC). Source: Toxin and Toxin Target Database (T3DB)

Note: This chemical does not meet GHS hazard criteria for 2.6% (50 of 1901) of reports. Source: European Chemicals Agency (ECHA)
Signal: Warning Source: European Chemicals Agency (ECHA)
GHS Hazard Statements: H315 (84.2%): Causes skin irritation [Warning Skin corrosion/irritation]; H317 (97.3%): May cause an allergic skin reaction [Warning Sensitization, Skin] Source: European Chemicals Agency (ECHA)
Precautionary Statement Codes: P261, P264, P272, P280, P302+P352, P321, P332+P317, P333+P317, P362+P364, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
ECHA C&L Notifications Summary: Aggregated GHS information provided per 1901 reports by companies from 22 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 50 of 1901 reports by companies.; There are 20 notifications provided by 1851 of 1901 reports by companies with hazard statement code(s).; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)

Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record

Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.

Additional source coverage and match status

Source	Result	Checked
NIH PubChem PUG-View	Exact match	2026-08-31

A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

4-Phenylbut-3-en-2-one (Benzylideneacetone)

Chemical / IUPAC name

Benzylideneacetone; 4-phenylbutenone

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

Key data

CAS

122-57-6

204-555-1

Annex

Entry number

356

Direct matches are limited for this record, so nearby entries from Annex II are shown as well.

Annex II 355