Halogenated ethers are a subcategory of ethers—organic chemicals that contain an oxygen atom connected to two alkyl groups or similar structures. An example of an ether is the solvent diethyl ether. Halogenated ethers differ from other ethers because there are one or more halogen atoms—fluorine, chlorine, bromine, or iodine—as substituents on the carbon groups. . Examples of commonly used halogenated ethers include isoflurane, sevofluorane and desflurane.