Citronellol is a volatile fragrance chemical extracted from geranium, rose and other plants, citronellol has a characteristic grassy, ​​citrus-like scent. Applied to the skin, it may cause deterioration when exposed to air. This exposure causes the unstable citronellol molecule to oxidize, which is thought to trigger skin deterioration. https://www.paulaschoice.com/ingredient-dictionary/ingredient-citronellol.html?q=Citronellol&fdid=ingredients