The saturation of four perfluorohydrocarbon liquids - Flutel RM 82, Flutel RM 101, Flute RM 170 and Flutel RM 175 - with oxygen and carbon dioxide and also the decarboxylation of these RMs with oxygen have been studied. Differences between the data as declared by the producer and the actual values were observed. Still, all Flutels investigated can be applied in liquid ventilation trials.