The question of whether saltwater pools are beneficial for the skin is common for swimmers seeking a gentler alternative to traditional chlorine water. Saltwater pools are becoming increasingly popular, offering a swimming experience that many describe as softer and less irritating. The key difference lies not in the absence of a sanitizer, but in the method used to generate the cleaning agent. This article explores the specific chemistry of saltwater pools and how that composition interacts with skin health and hydration.
Understanding the Chemistry of Saltwater Pools
A significant misconception about saltwater pools is that they are chlorine-free. In reality, a saltwater pool utilizes dissolved sodium chloride (common salt) to create the necessary sanitizer through electrolysis. A specialized piece of equipment, known as a salt cell or chlorine generator, passes an electrical current through the mildly salty water, converting the salt into chlorine (sodium hypochlorite and hypochlorous acid).
This method ensures a consistent and controlled delivery of chlorine, rather than relying on the periodic addition of tablets or liquid. The concentration of salt required is low, typically ranging from 2,800 to 4,200 parts per million (ppm). This salinity is approximately one-tenth the salt level of the ocean, and is similar to the natural salinity of human tears.
How Saltwater Affects Skin Hydration and Barrier Function
The low concentration of salt is a primary reason for the pools’ reputation as being gentler on the skin. The mild saline environment is less likely to strip the skin of its natural protective oils, known as sebum, compared to higher concentrations of chemical additives. Maintaining these natural oils helps preserve the integrity of the stratum corneum, the outermost layer of the skin that serves as the barrier function.
Some swimmers describe the water as feeling “silkier” or “softer,” possibly due to the subtle osmotic effect of the low salt level. Low-level sodium chloride solutions can act as a humectant, potentially drawing moisture toward the skin and preventing the rapid water loss often associated with swimming. However, any water allowed to evaporate from the skin can leave residue that may cause dryness, so rinsing is still advised.
Direct Comparison to Traditional Chlorine Pools
Saltwater pools offer a distinct advantage over traditional pools regarding irritation, despite both systems relying on chlorine for sanitation. The continuous, low-level generation of chlorine in a saltwater system typically results in fewer irritating chemical byproducts. The most common source of the strong “chlorine smell” and eye irritation in traditional pools is not the free chlorine, but compounds called chloramines.
Chloramines form when free chlorine reacts with organic contaminants like sweat and urine. The consistent sanitation and oxidation process within the salt cell help eliminate these chloramines at a steady rate. Consequently, saltwater pools generally produce fewer irritating compounds, leading to less redness, itching, and respiratory discomfort, especially for individuals with sensitive skin conditions.
Post-Swim Skin Care Recommendations
Regardless of the pool type, a simple and immediate post-swim routine is the most effective way to protect the skin barrier. The first step should always be to rinse the entire body thoroughly with fresh, clean water as soon as possible after exiting the pool. This action removes any residual salt, chlorine, or other trace contaminants from the skin’s surface before they can cause dehydration or irritation.
Following the rinse, promptly apply a rich moisturizer or emollient to the body while the skin is still slightly damp. This seals the water into the outer layer of the skin, preventing transepidermal water loss and helping to restore the skin’s natural moisture balance. Choosing a gentle, fragrance-free cleanser can also assist in rebalancing the skin’s pH without stripping away beneficial oils.