With respect to laser-based applications below 200 nm, fluoride materials used as layer and substrate materials are most prominent in optical components for beam shaping, steering and focussing. High band gaps and comparatively low extinction coefficients are the outstanding parameters of these components. However, fluoride coatings are exceedingly sensitive concerning surface contamination, handling, ambient atmosphere, humidity and total energy load. A set of fluoride layer stacks from different coating plants has been investigated by spectroscopic methods measuring the optical performance, laser calorimetry detecting the absorptive losses and LIDT testing the radiation resistivity of the specimens. Another set of samples was applied to an UV treatment system in nitrogen atmosphere before testing the optical performance by the procedures listed above.