camphor

Camphor is a white, crystalline substance with a distinct, strong odor. Chemically, it is a terpenoid ketone named 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one. It occurs naturally in the wood and bark of the camphor laurel (Cinnamomum camphora) and related species in the Lauraceae family, where it can be present in significant amounts. Most camphor used commercially is now produced synthetically from turpentine oil or via oxidation of borneol.

Natural camphor can be extracted from plant material by steam distillation, yielding crude camphor that is purified to a white crystalline product. Synthetic camphor is manufactured through routes that start with pinene-rich streams from turpentine or related terpenes, followed by oxidation and crystallization to produce the camphor molecule.

Uses for camphor include medicinal, cosmetic, and fragrance applications. It has a long history as an external rubefacient and antipruritic in topical preparations, and it remains a component of many cough and cold balms, chest rubs, and lotions. In perfumery, camphor contributes a cooling, menthol-like note and acts as a aroma modifier. It is also found in some consumer products as a fragrance or preservative adjunct.

Safety and regulatory notes are important. Camphor can be toxic if ingested or absorbed in large amounts and may cause nausea, vomiting, seizures, or coma. Topical products containing camphor should be used only as directed, with dilution and avoidance of mucous membranes, and special caution is advised for children. Many jurisdictions regulate camphor content in consumer products to reduce risk of poisoning.