This invention relates to compositions comprising highly fluorinated, chloro-substituted, non-cyclic organic compounds having 7 to 9 carbon atoms and to processes of making and using them. More particularly, this invention relates to emulsions comprising those highly fluorinated, chloro-substituted organic compounds. This invention also related to emulsion comprising noncyclic perfluorochlorethers having 7 to 10 carbon atoms, preferably 7 to 9 carbon atoms. These novel emulsions have various medical and oxygen transport applications. They are especially useful medically as contrast media, for various biological imaging modalities such as nuclear magnetic resonance, ultrasound, x-ray, computed tomography, .sup.19 F-magnetic resonance imaging, and position emission tomography, as oxygen transport agents or "artificial bloods," in the treatment of heart attack, stroke, and other vascular obstructions, as adjuvants to coronary angioplasty and in cancer radiation treatment and chemotherapy.