Pool chemicals are necessary for maintaining a clean and safe swimming environment, but they can pose dangers if mishandled or if the water chemistry is neglected. These substances are primarily used for sanitation to prevent the spread of waterborne illnesses, such as E. coli and Cryptosporidium, and to inhibit the growth of algae. They also balance the water’s acidity and alkalinity, which protects both swimmers and pool equipment. The danger is twofold: the immediate hazard of concentrated products and the health risks associated with poorly balanced water quality during swimming.
Acute Dangers of Concentrated Chemicals
The concentrated chemical products used to maintain a pool are inherently hazardous due to their corrosive and reactive nature. pH adjusters, such as muriatic acid or sodium bisulfate, are highly corrosive and can cause severe chemical burns upon contact with skin or eyes. These substances are also toxic if inhaled, leading to symptoms like coughing, choking, and chest discomfort.
A particularly severe risk involves the accidental mixing of chlorine products with acid-based pH adjusters. This combination instantly produces toxic chlorine gas, which is a respiratory hazard that can quickly cause lung damage and is irritating to the eyes, nose, and throat.
Concentrated granular products, such as pool shock, also carry an inhalation risk from the fine dust they generate during handling. Improper storage is a hazard, as chemicals must be protected from heat, moisture, and ignition sources. Storing incompatible chemicals near each other can lead to dangerous reactions, even without direct mixing.
Health Risks from Imbalanced Water Chemistry
The health risks experienced by swimmers are typically not from the sanitizer itself but from the unintended chemical byproducts created when the water is not properly balanced. The strong “chlorine smell” often associated with pools is not the odor of free chlorine working, but rather the odor of chloramines (combined chlorine). Chloramines are disinfection byproducts that form when free chlorine reacts with nitrogen-containing organic matter, such as sweat, urine, and cosmetics introduced by swimmers.
Chloramines are the primary cause of common health complaints, including eye and skin redness, and respiratory irritation. In poorly ventilated indoor pool environments, the buildup of chloramines can exacerbate asthma and other respiratory issues, especially in sensitive individuals. This irritation is a direct sign that the pool water needs to be “shocked” to break down the combined chlorine and restore the free chlorine residual.
The water’s pH level also significantly impacts swimmer comfort and health. The ideal pH range for pool water is generally between 7.2 and 7.8, closely matching the pH of human tears. If the water becomes too acidic (low pH), it can cause rapid eye and skin irritation. Conversely, if the water is too alkaline (high pH), the chlorine’s ability to kill germs is drastically reduced, and the water can cause severe skin dryness and rashes.
Safe Handling and Storage Practices
Mitigating the dangers of pool chemicals requires strict adherence to safety protocols during both handling and storage. Always wear appropriate Personal Protective Equipment (PPE) when working with concentrated chemicals, which includes gloves and eye protection to shield against corrosive splashes. It is also necessary to handle chemicals in a well-ventilated area, especially when dosing, to prevent the inhalation of fumes or dust.
A fundamental rule when preparing solutions is to “Always Add Chemical to Water,” never the reverse, to prevent a violent reaction or “wetting” that could release gas. If a chemical needs to be diluted before adding it to the pool, use a large bucket of water first, then slowly pour the chemical into the water. Never mix different pool chemicals together in a single container, even if they are meant to be added to the pool sequentially, as this risks a hazardous reaction.
Proper storage is necessary to isolate the potential hazards of concentrated products. Segregate chemicals in storage, keeping acids and chlorine products physically separated to eliminate the risk of accidental mixing. Store chemicals in a cool, dry place below 95°F and ensure they are kept in their original, clearly labeled containers, away from children and pets.
Regular water testing with strips or kits is an essential preventative measure. It ensures the pH and free chlorine levels are maintained within the ideal range, which ultimately mitigates the formation of irritating and harmful chloramines.