Ingredient guide ›

Alpha Isomethyl Ionone

A soft, powdery scent.

What it does

Adds a soft, powdery, violet-like smell to fragrances.

Good to know

It's one of the EU's listed fragrance allergens, so it must be named on the label above 0.001% in leave-on and 0.01% in rinse-off products. Sensitive skin may react.

Often found in: Deodorants, Shower gels, Shampoos

Around the world

• United States: No label rule yet. A 2022 law told the FDA to require fragrance allergen labels, but that rule isn't out. Source
• EU and UK: Must be named on the label above 0.001% in leave-on and 0.01% in rinse-off products. Source
• Canada: Must be named on the label above 0.001% in leave-on and 0.01% in rinse-off products (since April 2026). Source
• Australia: No limit in Australia's Poisons Standard. Source

Sources

• SCCS opinion: Fragrance allergens in cosmetic products (2012) (Independent)
• RIFM: Fragrance material review on alpha-iso-methylionone (2007) (Industry-funded)