Limonene (limonene)

Limonene is a naturally occurring terpene commonly found in the rinds of citrus fruits such as oranges, lemons, and grapefruits. In cosmetic formulations, it is primarily used as a fragrance component to impart a fresh, uplifting, and citrus-like aroma. While it enhances the sensory experience of products, limonene can oxidize when exposed to air, and its oxidized form may trigger sensitivity in individuals prone to fragrance allergies. For this reason, it must be declared separately on ingredient labels when present above regulatory thresholds.