Eugenol is sometimes called clove oil because it is the active element in cloves. It causes the aromatic smell typical of cloves and because of this property is often found in perfumes.
Eugenol is an allyl chain-substituted guaiacol (2-methoxyphenol). It appears as a clear or pale yellow oily liquid. Besides cloves, it can also be extracted from cinnamon and other aromatic spices. It is slightly soluble in water and soluble in organic solvents.1
The medical field makes use of Eugenol. Its properties make it a good local antiseptic and analgesic. It is used in dentist offices to make zinc-oxide eugenol paste for temporary fillings2. It also makes a good local anaesthetic for temporary relief from toothache pain3. It is used in the production of isoeugenol for the manufacture of vanillin which is an artificial substitute for vanilla.
Eugenol is found in insect attractants as well as UV absorbers. Since it is an antioxidant it useful in the manufacture of plastics and rubbers, besides being beneficial when ingested in moderate amounts (keeping down the free radicals).
It is possible to consume too much eugenol. In fact the National Library of Medicine defines eugenol overdose as "poisoning from swallowing a large amount of eugenol oil (clove oil)." Some of the symptoms are shallow and rapid breathing, coughing up blood, blood in urine, burns in mouth and throat, abdominal pain, nausea, rapid heartbeat, dizziness, seizures, and even coma. Obviously, this is not a substance to be consumed in mass quantities. Persons experiencing an overdose should seek immediate medical attention. Vomiting should not be induced unless it is recommended by an official. A good step is to contact the Poison Control Center. The phone number of the Poison Control Center in the U.S. as of this writing is 1-800-222-1222.
Another place Eugenol has found a niche is in lotions. Anecdotal evidence suggests that it may have healing properties for sores, and help relieve rashes though it should not be used on open wounds4.
Eugenol has some interesting properties. Its specific gravity is slightly more than 1.06 at room temperature, making it heavier than water5. Its boiling point is about 252° C.It has about a 2 year shelf life before its potency begins to seriously degrade. It is recommended that it be stored in a cool, dry, and dark place.
2. Referencing article previously located at: http://www.dentistry.bham.ac.uk/ecourse/pages/page.asp?pid=1585 - Economic Botany at UCLA
3. Backwood Home
4. The Medicinal Properties Of Clove Oil
5. The Good Scents Company