Bromine

Bromine like chlorine and fluorine is a poisonous gas. Bromine salts have been used to treat acid indigestion or for sedation. Bromine can displace chlorine in some body functions. Too much can cause toxicity. Mild symptoms may include fatigue, weakness, irritability, disturbed sleep, slow mental processes and poor memory. More severe toxicity can cause confusion and drowsiness, delirium, stupor, depression, hallucinations, and, in the extreme, psychosis.