When it comes to swimming pools, owners have a few different methods of water disinfection available to them. The first and most common is through use of chlorine, usually calcium hypochlorite. Another method is bromine disinfection, which is useful in water sanitation for swimming pools, although not in drinking water, unlike chlorine. As with chlorine, however, bromine can be dangerous when it's in its chemical state. Bromine is rarely used to disinfect drinking water.
Discovered in 1825, bromine is a halogen, as is chlorine. It can react very quickly with other elements and it's also corrosive. It's also harmful to organic materials when in its chemical form. However, so is chlorine, meaning bromine is relatively the same when it comes to its safety in swimming pools. A bleaching agent like chlorine, bromine is chemically very similar and highly stable, making it a good chlorine alternative in pools.
Although it costs more per pound than chlorine, the greatest advantage to bromine is that it's extremely stable in swimming pool water. It'll bind with bacteria and organic material in the water and remain there, still working, while chlorine will have bound to those substances and then used itself up. The combined chlorine remaining is essentially useless. Bromine is also less irritating to the skin and eyes.
Bromine can't be used as a disinfectant for drinking water, unfortunately, because of its rock-solid stability. It reacts too quickly to bacteria and organic material, and any residue left would be too potent. It would also leave a terrible taste behind in drinking water strengths, though it can be used for emergency disinfection. In addition, the smell of bromine can linger on the skin because it's tougher to wash off than chlorine.
Both bromine and chlorine are poisonous and are classified as hazardous materials. Also, bromine can be more dangerous at smaller amounts. That doesn't mean brominated pool water, if accidentally ingested, is poisonous. At recommended levels, it's no more dangerous than a chlorinated pool would be. In pools, bromine has to be closely monitored and maintained within recommended levels. If levels are too high, a definite odor will result, as will eye and mucous membrane irritation in humans.
Bromine for pools comes in tablets that slowly dissolve, as well as in a special two-part liquid and granule system that dissolves very quickly. As with chlorinated pools, make sure the pH level in a brominated pool is between 7.0 and 8.0; the ideal range is 7.4 to 7.6. Bromine levels should be at a minimum of 2.0 PPM, with 2.0 to 4.0 the ideal. Test your bromine regularly, using standard pool testing kits that have a bromine scale on them.