The most common ketone molecules are camphor (in spike lavender), menthone (in peppermint), carvone (in spearmint), and thujone. They are excellent mucolytics and are generally cooling when applied. Shelf Life: 3-5 years. Ketones irritate the skin. Please check the maximum dermal dilution for each oil to ensure they are diluted properly. As always, see individual oil profiles for specific uses.