Isoflurane (1-chloro-2,2,2-trifluoroethyl difluoromethyl ether) is a halogenated ether used for inhalation anesthesia. Together with sevoflurane, it replaced the flammable ethers used in the pioneer days of surgery. It is usually administered in conjunction with nitrous oxide and pure oxygen. Although its physical properties means that anaesthesia can be induced more rapidly than with halothane, its pungency can irritate the respiratory system, reversing the theoretical advantages conferred by its physical properties. It is usually used for maintenance of anesthesia that has been induced with another drug.

Though it vaporizes readily, it is a liquid at room temperature.

physical properties

Molecular weight -- 184.5 Boiling point °C at 760 mm Hg -- 48.5 Specific gravity at 25 °C -- 1.496 Vapour pressure mm Hg: at 20°C -- 238 at 25°C -- 295 at 30°C -- 367 at 35°C -- 450