The skin is not just a protective covering — it’s an active organ responsible for barrier protection, immune defense, and temperature regulation. However, regular exposure to chlorinated water can weaken its protective functions.
According to researchers, when chlorine reacts with organic matter found in water and on the skin, it forms harmful by-products such as:

• Trihalomethanes (THMs)
• Chloroform
• Carbon tetrachloride
• Dioxins

These substances are potential carcinogens and can enter the body even through simple washing or showering.
Chlorinated water can cause the following skin effects:

• Disruption of the lipid barrier — skin loses moisture, becoming dry and vulnerable
• Irritation, itching, and flaking, especially in people with sensitive skin or dermatological conditions
• Weakening of the skin’s local immune defenses, increasing the risk of inflammation and skin infections

Chlorine poses a particular risk to children.
Research shows that children may experience inflammation of the mouth, throat, and esophagus, and frequent exposure to chlorinated swimming pools is linked to a higher risk of developing bronchial asthma.

The scientific community has taken this issue seriously — and the findings are concerning:
🔬 "Hard water contributes to the development of atopic eczema in children"
Journal of Allergy and Clinical Immunology, 2017
Children living in areas with hard water are significantly more likely to suffer from eczema. Minerals in the water damage the skin barrier, making it more permeable to allergens.
🔬 "The effect of water hardness on surfactant-induced irritation"
International Journal of Cosmetic Science, 2018
Hard water intensifies the irritating effects of soaps and cleansers. Even gentle skincare products become harsh when used with hard water.
🔬 "Skin cleansing with hard vs. soft water: Impact on skin barrier function"
Clinical, Cosmetic and Investigational Dermatology
Regular use of hard water reduces natural moisturizing factors in the skin, leading to dryness and flaking.
What’s really happening:

• The skin’s protective barrier is disrupted: moisture is lost, making skin vulnerable and prone to inflammation.
• A soapy residue remains on the skin’s surface, preventing it from “breathing.”
• The pH balance is disturbed — especially problematic for those with sensitive or dry skin.

The result?
Discomfort, visibly worsened skin condition, and in children — an increased risk of developing atopic dermatitis.

A study published in Advances in Therapy (2020) reveals that moderate levels of certain minerals in water can actually benefit the skin:
🔹 Magnesium & Zinc

• Strengthen the skin barrier and reduce inflammation
• Support faster recovery from microdamage
• Especially helpful for sensitive skin or those prone to dermatitis

🔹 Selenium & Strontium

• Help reduce the production of inflammatory substances (cytokines)
• Alleviate symptoms of rosacea and psoriasis

🔹 Silicon Dioxide & Calcium Bicarbonate

• Reduce histamine release, thereby easing itching and irritation — particularly useful in managing eczema

Source: "The Role of Mineral Elements in Skin Health," Advances in Therapy, 2020

Most municipal water systems deliver water with a pH between 7 and 8.5 — neutral to mildly alkaline. This is done to protect pipes from corrosion, but it’s not necessarily good for your skin.
A study published in the International Journal of Cosmetic Science (2006) found that even brief exposure to alkaline water raises the skin’s pH, making it drier and compromising the lipid barrier.
Source: Lambers et al., “Natural skin surface pH is on average below 5, which is beneficial for its resident flora”
Why can alkaline water harm your skin?If you regularly shower or bathe in water with a pH above 7, it may lead to:

• Damage to the skin’s acid mantle
• Increased dryness, tightness, and flaking
• Disruption of the skin microbiome (encouraging growth of harmful bacteria and fungi)
• More inflammation and itching, especially in conditions like eczema, rosacea, or psoriasis

According to the Journal of Investigative Dermatology (2001), restoring the skin’s natural pH after washing with water at pH 8 can take up to 6 hours — particularly for people with dry or mature skin.
Source: Schmid-Wendtner & Korting, “The pH of the skin surface and its impact on the barrier function”