Linalool and limonene are fragrance ingredients that can break down into irritating compounds (hydroperoxides) when exposed to air and light. Studies show these oxidized forms trigger allergic reactions in a significant portion of people with sensitive skin, yet they're not routinely tested for in Europe—meaning you might not know if you're allergic until you react.

This was a literature review examining existing patch test studies (the gold standard for detecting contact allergies) on linalool and limonene hydroperoxides. Researchers looked at test results, reaction rates, and current testing practices across dermatology research.

Funding not disclosed in abstract