pH value

Interesting facts about pH

What factors influence pH?

The skin’s own various sources of acidic substances and buffer substances (sweat, sebum, metabolic processes in the horny layer and microorganisms on and in the skin) determine the pH from within. They in turn are subject to internal influences, e.g. hormones, illnesses, gender and age. Inflamed skin or open wounds also have a pH above 5.5. This is compounded by many external influences such as diet, medication, climate, social contacts, professional activity, lifestyle habits and, last but not least, skin cleansing and care. The use of soap or products with a neutral or alkaline pH for skin cleansing can lead to an increase in the skin’s pH. Skin care products with a pH above 6 can cause the skin to be less acidic than necessary for its health.

Why do different areas of the body have different pH values?

The face, scalp, hands, feet, arms, legs, back, chest, stomach, armpits and intimate areas differ in terms of skin structure, hairiness, density of sebaceous and sweat glands and colonisation with microorganisms. As the skin’s pH is influenced by these factors, it varies depending on the location. A pH above the normal average value of 5.5 is found in particular in the areas between the fingers and toes, the armpits and in the genital area, but also in skin folds (under the breasts in women, between the buttocks and folds due to excess fat).

Measuring pH

Although our sense of taste allows us to perceive pH values (acidic, neutral or bitter taste), this method is not suitable for corrosive acids and alkalis or even toxic substances. Various dyes make pH changes visible. These indicator substances are used for quick estimates of pH. An electrochemical measurement with a pH meter, which is also used to determine the pH on the surface of the skin with special adaptations, is more accurate. Fluorescent dyes and modern imaging methods (fluorescence lifetime imaging – FLIM) can visualise different pH values microscopically in the individual skin layers.

What is the effect of the pH5.5 of Sebamed?

The pH 5.5 of sebamed is adapted to the skin’s natural protective layer. This means that sebamed products can ideally support healthy skin functions. This optimises product compatibility and the care effect even for sensitive skin.