Camphor Worst Irritant No known benefits Camphor description Aromatic substance obtained from the wood of a tree common to Southeast Asia, _Cinnamomum camphora_ or manufactured synthetically. When applied to the skin, camphor produces a cooling effect, which can cause skin sensitivity with repeated use. Inhaling camphor at concentrations of 2 ppm (parts per million) or more may cause sensitivity of the mucous membranes. Camphor can also cause skin and eye sensitivity on contact. Related ingredients: Cinnamomum Cinnamon Cinnamomum Camphora