What is pH?
The term “pH” refers to “potential of hydrogen” and concerns the activity of hydrogen ions (molecules that carry a positive or negative charge) in a water-based solution. Hydrogen makes up 2/3 of water, as water consists of 2 hydrogen molecules and 1 oxygen molecule, H²O.
The pH of a solution is indicated by a numeric scale from 0-14. 7 is pH neutral, anything below 7 is considered acidic, and anything greater than 7 is considered alkaline. Lemon juice has a pH of 2 which is very acidic, while ammonia has a pH of 12, which is highly alkaline.
What is the pH of skin?
Although different research studies cite varying numbers the collected research shows skin’s average pH to be 4.7 making it naturally acidic. Men’s skin tends to be more acidic than women’s skin, and although the pH of our skin increases with age, it remains acidic.
What is the skins ‘acid mantle’?
Skin has a protective film on its surface known as its acid mantle. The acid mantle plays a vital role in protecting the skin’s surface and lower layers from external threats. Skin’s acidic pH also plays a role in keeping its delicate microbiome balanced. An acidic microbiome makes it more difficult for harmful pathogens to multiply but lets the good microbes flourish.
How does pH affect skin?
When the skins pH is repeatedly disturbed it may cause or worsen skin problems. A dry, tight feeling is often the first sign that skin is suffering from a pH imbalance.
Highly acidic (pH 2.5 or lower) or alkaline (pH 8 or greater) products can cause a significant disruption in skin’s pH making it vulnerable to factors that can trigger breakouts, signs of eczema, redness, and sensitivity. That is why daily use of products with a pH that is too high or too low can visibly and progressively damage the skin.
To avoid skin problems, many people look for pH-balanced skin care products. This refers to products formulated with a pH that falls in the range of normal, healthy skin. That range is most often cited as being between pH 4 and pH 7, but studies have shown that skin with pH values below 5.0 is in a better condition than skin with pH values above 5.0.