Skip to content

Banned fragrance

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

CAS 122-57-6
25

Safety score · 0–100

Caution

Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.

Benzylideneacetone (4-phenylbut-3-en-2-one) is a floral fragrance compound prohibited in EU cosmetics. It is a strong skin sensitizer with documented irritation and toxicity risks and should not appear in skincare.

Skin benefits

  • Provides sweet floral notes resembling sweet pea and hyacinth
  • Useful at very low levels in fine fragrance

Known concerns

  • Listed as prohibited in EU cosmetics under Annex II (entry 1379)
  • Documented strong skin sensitizer with significant irritation potential
  • Toxic if swallowed and harmful by inhalation per GHS classifications
  • Specifically not recommended for cosmetic use by fragrance authorities

References

EU

EU CosIng database

European Commission cosmetic ingredient registry: regulatory status, restrictions, authorised functions.

Check your shelf

Find 4-Phenylbut-3-en-2-one (Benzylideneacetone) in your products.

Scan any cosmetic product with LuxSense to see if it contains 4-Phenylbut-3-en-2-one (Benzylideneacetone) and get a full ingredient breakdown with safety scores.

This profile is for educational purposes and does not constitute medical advice. Regulatory status and scientific understanding evolve, so always read the physical product label and consult a healthcare professional for personal concerns.