For your education — I found a link to a video on fluorine, the most reactive element in the entire periodic table. This stuff is extremely dangerous by itself, but it exists all around us bound up in molecules such as tin fluoride and sodium fluoride. Fluoride compounds are found in our toothpaste and water to enhance good dental hygiene, among other uses.
One of my friends is a chemical engineer. In his job, he’s handled any number of highly toxic, corrosive, and otherwise dangerous chemicals. Hydrofluoric acid is the one chemical he is actually afraid of.
This just one in a whole series of Periodic Table of Videos. Apparently the video below is actually an update to an earlier video. Fluorine is so difficult to handle in its native state that they had trouble getting the video they wanted. Fortunately they found a chemist who has considerable knowledge and experience in working with elemental fluorine.