Abstract: The present invention describes biologically compatible inert perfluorocarbon liquids capable of removing carcinogens from cells and thereby reducing the risk of cancerous cell transformation. This invention can be used to reduce the build-up of carcinogens, and thus be used as prophylactic medicaments in reducing the risk of chemically induced cancerous cell transformation and thus cancer. These liquids can be used as medicaments applied to any organ of the body; such an application would reduce the build-up of carcinogenic chemicals within cells of that organ and as such can be used to reduce the risk of a variety of cancers produced through chemical carcinogenesis. Such cancers include lung cancer, stomach cancer, rectal cancer, and certain types of skin cancer.