alpha-Terpinene

Say itAL-fuh-TUR-pih-neen

Lime-like, lemony terpene with medicinal, thymol-camphor and woody tones.

What it is: A molecule made from a natural raw material.
Where it comes from: made by acid rearrangement of pinene or limonene
When you smell it: Top notes: when you spray it.
What perfumers do with it: Fresh lime-terpene lift in citrus and spicy tops, and a spicy touch in mango; its bulk use is scenting industrial fluids.
Worth knowing: In tea tree oil it works as a built-in antioxidant, reacting with air before other molecules do, and the products it forms are stronger skin allergens than the fresh molecule.
Rules: Limited. EU label-named allergen since Regulation (EU) 2023/1545; peroxide value must stay under 10 mmol/L
Also called: alpha-terpinene; α-terpinene; p-mentha-1,3-diene