So, what is pH?
pH is a measure of how acidic or alkaline a water-based product is. On the scale of pH, that ranges between 0.0 to 14.0 a pH of 7 is considered neutral. Any pH reading below 7 is considered acidic, and vice versa, any pH reading above 7 is considered alkaline.
Our skin has a pH too. Getting pH readings of skin from different complexion and ethnicity gives a narrow range of between 4.5 and 5.5. That’s slightly acidic, and if you try to taste your skin, you’ll also feel it (Assuming you didn’t wash it with soap lately, which reduces the skin’s acidity).
pH of the Skin
The acidity on the skin’s surface plays a crucial role in its overall health. It stimulates the production and secretion of the skin’s sebum that allows makes it supple and will enable it to repair quickly. It also inhibits the growth of bad bacteria, which find it hard to live on a surface with that acidity level. That’s why maintaining a balanced pH is essential for the health of our skin. Any significant shift up or down in skin pH could destabilize it and cause redness, increase skin shedding and a longer healing process.
Common Products and Their pH
Soap 7.5 – 10.0
Blood 7.35 – 7.45
Tomato Juice 4.0
Orange juice 3.0
Lemon Juice 2.0
Distilled Water 7.0
Sea Water 8.5
Baking Soda 8.0
Gastric Acid 1.0
The pH Scale
Another interesting aspect of the pH is its scale of measurement. This is not a regular linear scale but a logarithmic one.
In short, a logarithmic scale means that every decrement of one unit, let’s say from 6 to 5, the acidity value is multiplied by 10 (!). So, orange juice with a pH of 3.0 is 10x more acidic than tomato juice with a pH of 4.0. The same goes for the alkaline portion of the pH scale – every increase of 1 unit, let’s say from 8 to 9, means that the alkalinity was multiplied by 10 as well.
And for that reason, lemon juice is 100 times more acidic than tomato juice…
Worng pH is bad for the skin
Repeatedly using highly alkaline skincare products can cause various problems, such as increasing the ability of the skin to “breath” and even make the skin’s follicles swell.
Highly alkaline products are usually soaps and surfactants that are present in skincare lotions.
Ideally, the pH level of the skincare products you use daily should reside between a pH of 4.5 and 6.0. Those products that are leave-on (stay on the skin) should lie on the lower side of that range.
pH is a serious matter that is often disregarded. Always check that the skincare products you use are pH balanced!