4-METHYLPENT-3-EN-2-ONE is graded A** (Safe) by Expert·ING, based on COSING regulatory data.

4-METHYLPENT-3-EN-2-ONE

Mesityl Oxide

Safety grade: A**

Mesityl oxide is a synthetic fragrance chemical that has a sweet, honey-like, and slightly fruity scent. It is a small organic molecule created in a laboratory and commonly used to add pleasant aromas to cosmetic products.

This ingredient is used in cosmetic products purely to impart or enhance fragrance, giving products a pleasant and appealing scent.

Graded using: COSING.

Last verified: May 26, 2026