The term “pH value” has been widely discussed for years now. There is hardly anyone who hasn’t heard it or read it on shampoo bottles or tubs of cream. But how many people are actually aware of what this abbreviation stands for and what it means?
“pH” is short for the Latin term “potentia hydrogenii” and translates to “hydrogen ion concentration”.
pH values allow us to differentiate acids and bases from each other and label them according to strength. Anything that contains water also has a pH value, which can be determined using an electronic pH meter or an indicator such as litmus.
Our skin can be assigned a pH value because the hydrolipid film on the skin’s surface contains water. It was discovered about a hundred years ago that the skin is slightly acidic. Modern measuring techniques showed an average skin pH value of 5.5, which is due to natural acidic substances in sweat, sebum, and skin cells. The significance of the acidic nature of the skin’s surface is demonstrated in the concept of the “acid mantle”.
The skin's acid mantle repels harmful microorganisms and negative environmental influences and, in doing so, protects the skin from infections, irritation, allergies, and dryness. An intact acid mantle also functions as a natural deodorant because it minimizes the bacterial breakdown of sweat, which causes body odor.
It is therefore vital that you don’t do anything that could damage your acid mantle. You should for example avoid cleansing your body with “normal” soap, because the soapy water will have a pH value of 8 to 12 and will destroy the acid mantle. Washing with “pH neutral” products, whose pH values of 7 differ considerably from the skin’s of 5.5, can harm the acid mantle, as well. And finally, you should steer clear of any contact with basic solutions if you can.
The skin’s natural acid mantle repels pathogens, ensuring that the skin’s barrier function is maintained. This stops it from drying out and prevents irritants and pollutants from penetrating your skin. Substances with a neutral pH value attack the acid mantle and if this outer layer is unstable, they can even destroy it. This is often the case in young children, mature adults, and those with skin that is damaged or highly irritated. This decreases the skin’s resistance against pathogens that lead to dehydration, irritation, and allergic sensitivity. pH-neutral products, such as soaps and creams with a pH of 7, are therefore not the best products for promoting your skin’s natural functions. They actually increase the skin’s pH value, and even if they are rinsed off quickly, your skin will need several hours to return to a pH of 5.5.
The ingredients in modern skin care products moisturize the skin very well, preventing dryness and protecting it from environmental influences, but an extremely high pH will minimize these effects by suppressing your skin’s natural functions instead of strengthening them. Products with a pH of 5.5 are the most effective carers for your skin and also the most compatible. Many consumers assume that products advertised as skin-friendly or skin-neutral have the right pH value. In truth, all pH values have been found in these products.
There are cleansers and washes that are far too acidic, thus irritating sensitive skin, but there are also pH-neutral products. Some of these are even alkaline. On top of this, the pH value of products often changes over time. We guarantee that the pH of sebamed products will not deviate from 5.5 by more than 0.3 pH units throughout their shelf life. You can’t be sure that this will be the case with products advertised as skin-friendly or skin-neutral.