Abstract: The use of perfluorinated heterocyclic compounds of the general formula I, ##STR1## wherein n represents 2-8,X and Y represent a --CF.sub.2 OCF.sub.2 -- group, a --CF.sub.2 --CF.sub.2 --CF.sub.2 -- group or a --CF(CF.sub.3)--CF.sub.2 -- group, andY is a --CF.sub.2 --O--CF.sub.2 -- group, a --CF(CF.sub.3)--CF.sub.2 -- group or a --CF.sub.2 --CF.sub.2 --CF.sub.2 -- group,or mixtures thereof, is described as emulsion-stabilizing additives in medically usable aqueous emulsions of perfluorocarbons, optionally containing hetero atoms, suitable for use in blood substitutes. The compounds are obtained by electrochemical perfluorination.

Abstract: Compositions composed of fluorochlorohydrocarbons selected from the group consisting of the dichlorotrifluoroethanes in admixture with lower alkanols. The compositions are especially suitable for use as cleaning compositions, particularly for removing organic resin fluxes or flux residues from printed circuit boards.