Fluoride ions are acutely and chronically toxic. Exposure to less concentrated solutions may have equally serious but delayed effects. Physiological Properties HF has poor warning properties . The odor threshold for humans is 3 ppm and irritation of mucous membranes begins at 5 ppm. If you can smell it, chances are the concentration is too high and immediate steps must be taken to lower it.
Fluoride ions migrate through the body destroying tissue until lodging in the bones.
If you are exposed to hydrofluoric acid seek prompt medical attention, even if you do not feel pain . Keep a supply of calcium carbonate to absorb spills. Before beginning any procedure involving HF, make sure the nearest safety shower and eyewash is accessible and in proper working condition. Work in a fume hood with the sash closed as much as possible. Wear goggles and a face shield, a lab coat, pants or a long skirt and closed-toe shoes.