What exactly is skin pH? It’s short for ‘potential hydrogen’ and it refers to the acidity level of the skin. A pH of 7, which is the acidity level of pure water, is considered neutral. Anything below that value is acidic and alkaline above it. The optimal pH value of human skin – on most of our face as well as our body – lies somewhere between 4.7 and 5.75. This means that skin’s natural pH is mildly acidic.
Skin’s pH does vary, depending on the area of the body. The general rule of thumb is that lesser exposed areas of the skin tend to maintain their natural acidity, while the face, chest, and hands are usually more alkaline. These differences are due to the simple fact that these areas of skin are, in normal circumstances, more exposed to the elements.
Internal and external factors
This leads us to endogenous and exogenous factors that impact skin pH. Regulation of pH is one of the most complex mechanisms in human physiology and these mechanisms form the basis of endogenous, or internal factors. They are affected by age, genetic predisposition, and ethnic differences, as well as sebum production, skin moisture, and sweat. Exogenous, or external factors, include air pollution, antibacterial products, cosmetics, detergents, change in seasons, sun exposure or even washing skin too frequently.
Skin acidity also forms a part of the skin barrier called the acid mantle, a slightly acidic film on the surface of the skin that acts as a barrier to bacteria, viruses, and other external contaminants. Since blood is slightly alkaline, bacteria that become adapted to the acidic pH of the skin will encounter an environment to which they are less adapted, making them weaker and more vulnerable to the antibodies in our immune system.
It should come as no surprise, that changes in skin pH can be a contributing factor to all kinds of skin diseases and disorders, like eczema, acne, and dermatitis, to name just a few. With all this in mind, it becomes clear that the effects of exogenous factors have greatly increased in recent years due to pollution, as well as the behaviors and habits that tend to make skin disorders an increasing problem, especially for those with sensitive skin.
Innovation and technology
This presents two opportunities for the beauty industry. Syndets are cleansers with non-soap-based surfactants. They are generally neutral or acidic compared to soap-based cleansers which are typically alkaline; for instance, washing hands with soap causes the pH on the palms to increase by a mean of three units and remains altered for 90 minutes after washing.
The higher pH of soap bars may be a contributing factor in the higher irritation potential of soap bars compared to syndet bars. Therein lies the opportunity for beauty brands who are willing to innovate and develop solutions to alleviate problems caused by negative exogenous factors. Provital is committed to just that. CaresoftTM innovatively acts on the internal mechanism of skin pH control, repairing the skin barrier function and causing a decrease in skin reactivity and sensitivity.
Innovation is at the heart of the second opportunity as well. Technologies like skin assistant apps help people who are experiencing skin problems to augment their everyday life by helping them detect when their skin is experiencing a change in its pH. This allows them to react in a timely manner and avoid at least some of the skin problems caused by pH change. There is a strong opportunity here for brands to utilize both technology and biology to ameliorate the quality of life of people affected. This will be especially interesting for Generation Z, as they are more used to technology, as well as people affected by long term skin diseases.
A two-pronged approach
Skin pH is a delicate balance that can have a significant impact on skin health. As particularly exogenous factors become even more demanding on the skin, complaints from dryness to dermatitis are becoming increasingly common. This is why it is essential that the beauty and personal care industry continue to innovate; through a combination of effective, caring actives and sophisticated pH monitoring technologies, the industry can respond to the demand for evidence-based, scientifically-driven skin care solutions.