Limonene

limonene

What it is: A monoterpene, the main component of citrus peel oils.
Why it is used: A fresh citrus scent; it also acts as a solvent.
Where you usually find it: Orange, lemon and bergamot oils; perfumes, cleaning products, cosmetics.
Role in the fragrance: Top note, evaporates quickly.
Notes in the atlas: Bergamot, Neroli

What EU law says

Annex III to Regulation (EC) No 1223/2009: its presence must be indicated in the list of ingredients when its concentration exceeds 0.001% in leave-on and 0.01% in rinse-off products. One of the 26 allergens introduced by Directive 2003/15/EC. In detergents it is listed above 0.01% by weight under Regulation (EC) No 648/2004. Like linalool, it oxidises in air. Regulation 2023/1545 replaced its entry with new wording.

In detail: fragrance allergens and the deadlines of Regulation 2023/1545