Highly uncertain Hazards are discussed below. The free element has a characteristic pungent odour, detectable in concentrations as low as 20 ppb, which is below the safe working level. Exposure to low concentrations causes eye and lung irritation. Metal fluorides are very toxic.
Organic fluorides are generally much less toxic and are often quite harmless.
Chlorine Chlorine gas is very toxic because of its strong oxidising nature. Even low concentrations of chlorine gas attack eyes, throats, and lungs with painful effects. Chloride is relatively harmless. Bromine Bromine is a very corrosive oxidising liquid whose vapour attacks the eyes and lungs with painful effects. Bromides salts should be treated as toxic.