18Cineol

1,8-Cineole, also known as cineole or eucalyptol, is a cyclic ether monoterpene oxide with the chemical formula C10H18O. It is a major component of eucalyptus essential oil and occurs in a range of other plant oils, including bay laurel, rosemary, tea tree, and various eucalyptus species. In essential oils, cineole content can vary widely, often forming a large portion of the aroma profile.

Chemically and physically, 1,8-cineole is a volatile, lipophilic compound that presents a fresh, camphor-like odor. It is typically a colorless liquid with a boiling point around 176°C and is soluble in organic solvents but only sparingly soluble in water. It is commonly used as a fragrance and flavor ingredient due to its distinctive scent and flavor profile.

Industrial and pharmaceutical uses are diverse. Cineole is employed in flavorings, confectionery, chewing gums, and perfumery, as well as in cleaning products and cosmetics. In the pharmaceutical sector, it is a common constituent of inhalants, cough syrups, lozenges, and topical rubs for its perceived decongestant and soothing properties. Laboratory studies have investigated its antimicrobial and anti-inflammatory activities, though robust clinical evidence for therapeutic efficacy remains limited.

Safety and regulation reflect its status as a natural essential oil component. Concentrated cineole can cause irritation to skin, eyes, and mucous membranes and may be toxic if ingested in large amounts. It is approved as a flavoring agent in many jurisdictions at specified levels, but products containing essential oils should be used with caution, especially by children, pregnant individuals, and those with sensitivities.