Question of the Week
July 22, 2013
How toxic are pool chemicals?
What are pool chemicals? Are they toxic? To maintain commercial and private swimming pools, many chemicals are utilized to enhance and protect the water quality. These chemicals minimize bacterial and algal growth, and maintain a pH to enhance disinfectant action while minimizing skin and eye irritation.
Chlorine systems are the most common systems. For residential pools, chlorinated isocyanurates are used and these dissociate to form hypochlorite ions which are the disinfectant and cyanuric acid. Periodically, a “shock treatment” (granules or packets of sodium, calcium or lithium hypochlorite tablets) are utilized to recharge chlorine levels. The pH needs to be maintained within a narrow range to minimize skin/eye irritation and to enhance the action of chlorine. Sodium carbonate is used to increase pH. Muriatic acid or sodium bisulfate will lower pH. To help prevent a build up of chloramine in the system, a “stabilizer” consisting of cyanuric acid is added. Chloramine is formed from a reaction of chlorine with body fluids and lotions (various amines) that are washed off into the pool. Chloramine is what makes water smell like chlorine and is very irritating to eyes, airway, and skin. Lastly a buffer called “alkalinity” is added to the system to maintain pH within its narrow range and consists of sodium bicarbonate.
Prevention is the key to reducing medical problems when exposed to these chemicals. Medical concerns from these chemical exposures include:
Typical dangers in mis-handling and mixing chemicals include:
Question prepared by: John Benitez, M.D., MPH Medical Toxicologist