Sea water, due to its richness in salts, has a basic pH of around 8. The scalp, on the other hand, has an acidic pH of 5.5. This acidic pH of the scalp provides it with a protective role, this is what we call the acid mantle. Therefore, when swimming in the sea, the pH of the scalp is altered which can lead to scalp sensitisation, dryness and an increased risk of scalp diseases (such as dermatitis...).
Just as with chlorinated substances, sea water strips the hair fibre, promoting the lifting of the scales at the cuticle level, which can no longer perform their protective role. As a result, the hair becomes brittle and coarse.
When we are at the sea, it's not just the salt water that damages our hair. Indeed, the UV rays from the sun are known for their harmful effects on the skin, but their impact on our hair is often overlooked! Exposure to UV rays has an effect on our hair. These rays weaken our hair by damaging the keratin and thinning the hair shaft. Moreover, just like the rest of the epidermis, the skin of the scalp is sensitive to the sun's rays. Repeated and unprotected exposure could lead to desquamation with the appearance of dry dandruff.
It is therefore essential to know how to care for your hair against the side effects of sea water and sun. During beach holidays, it is necessary to adopt the right practices to maintain the appearance and health of your hair.