Yes, within the limits used in properly regulated commercial perfume — coumarin, the natural compound that gives tonka bean its sweet, hay-like, almost vanilla-almond smell, is subject to strict concentration limits precisely because it can cause skin sensitisation in some people at higher doses.

Why It’s Restricted Rather Than Banned

Coumarin is one of the ingredients monitored by international fragrance safety bodies (IFRA), which set maximum allowable concentrations based on safety research. That means a properly formulated perfume using tonka bean has already had its coumarin content calculated to stay within safe limits — it is not left to guesswork.

What This Means for Sensitive Skin

Like most fragrance materials, repeated exposure over time can occasionally lead to a developed sensitivity in some individuals, even within regulated limits, so if you notice irritation building with a particular tonka-heavy perfume, it is worth taking that seriously rather than pushing through it. This is one of many naturals we cover in our guide to perfume ingredients, and our allergies and sensitive skin guide explains how fragrance sensitisation develops more broadly. Both sit within the complete guide to perfume.