EVERYTHING YOU NEED TO KNOW ABOUT pH VALUE

Why are the pH value of the skin and pH values of skincare so important – and what does a pH value actually indicate?  

The pH value scale – read and understand

The pH scale ranges from 0 to 14. Values from 7 to 0 are referred to as increasingly acidic, while values from 7 to 14 are referred to as increasingly basic. A pH value of 7 is referred to as neutral. The natural pH value of the facial skin ('pH skin neutral') can vary, but is classified in the range of 5.4 to 5.9. (1)

How are pH value and skin microbiome related?

It is widely recognized that the normal pH value of the skin surface (along with other physicochemical functions) plays a positive role for the skin's microflora. The microflora of our skin – the so-called skin microbiome – consists of many different types of microorganisms such as bacteria, yeasts, and fungi.  

Benefits of a low, increasingly acidic pH value

A low skin pH value (4.0 to 4.5) supports the commensal bacterial flora on the skin and prevents the penetration of pathogenic microorganisms – bacteria that can cause diseases or skin infections. Reports suggest that a higher pH value (8.0 to 9.0) even promotes the growth of pathogenic bacteria. The acids produced by bacteria also contribute to the local defense mechanisms. For example, S. epidermidis, C. acnes, Pityrosporum ovale, and Corynebacteria split triglycerides into free fatty acids through lipases and esterases. This leads to a lower pH value on the skin surface, thus creating an unfavorable environment for pathogenic bacteria – the skin's acid mantle.

Furthermore, an acidic pH value of the skin also promotes the production of natural antimicrobial peptides, supports wound healing, and regulates the process of keratinization and desquamation. The skin flora also produces protein- or lipid-containing antibacterial compounds known as bacteriocins. These bacteriocins are involved in the control and regulation of bacterial competition for survival in this microenvironment. For this purpose, the bacteriocin-pep 5 produced by S. epidermidis is an example that is particularly active against other staphylococci, especially S. aureus. Interestingly, the acidic pH of the skin enhances the activity of these antibacterial lipids and peptides, possibly through improved interaction with the bacterial membrane. (1)

The pH values of DR. EMI ARPA SKIN

The Core Collection by DR. EMI ARPA SKIN consists of three products with pH values between 4.4 and 4.9. The Ten out of Ten Gentle Gel Cleanser is a mild yet effective gel cleanser that respects the skin barrier and has a pH value of 4.9. Water contact is already alkaline – the cleaner from DR. EMI ARPA SKIN counteracts with this pH value. The Essential Essence Skin Balancing Toner restores the skin's balance after cleansing with a pH value of 4.5 and provides intense hydration. The Moisturizer Barrier Boost CPA Barrier Cream has a pH value of 4.4 and serves as the optimal conclusion of the routine, acting like a strong protective barrier.  

SOURCES

(1) Barel, A.O., Paye, M., & Maibach, H.I. (Eds.). (2010). Handbuch der kosmetischen Wissenschaft und Technologie (3. Aufl.). CRC Press. https://doi.org/10.1201/b15273