fluorine combines with calcium. Safety CaF2 is classified as "not dangerous", although reacting it with sulfuric acid produces very toxic hydrofluoric acid. With regards to inhalation, the NIOSH-recommended concentration of fluorine-containing dusts is 2.5 mg/m3 in air. See also List of laser types Photolithography Skeletal fluorosis References External links NIST webbook thermochemistry data Charles Townes on the history of lasers National Pollutant Inventory - Fluoride and compounds fact sheet Crystran Material Data MSDS (University of Oxford) Calcium compounds Crystals Fluorides Fluorite Alkaline earth metal halides Optical materials Fluorite crystal structure