Skin’s pH and the Acid Mantle – the long, and the shorter story
THE SHORTER STORY
The surface of your skin contains a barrier, the acid mantle, which protects skin from contamination, bacteria and moisture loss. This delicate barrier can be easily disrupted by harsh chemicals and environmental pollution causing rashes, dryness, acne and blemishes. Products that support the acid mantle will be slightly acidic (to match your skin) and they will contain natural plant based substances that blend well and melt into your skin. We at DASH are particularly fond of this lovely mantle, and we are constantly on a mission to make all our products pH balanced and thus skin loving, protecting and gentle for your (and our!) faces and bodies.
FOR YOUR FACE we particularly recommend a daily use of Dash Hydrating facial mist, in addition to your regular moisturiser. Much more than a ‘toner’ (what’s a toner anyway?), our Hydrating mist delivers a hefty dose of conditioning and moisturizing as well as natural acidity, which is necessary for keeping the skin healthy. Apply it as a simple spritz before moisturizing, after cleansing, or at any point during the day (we also like it in the summer heat, or whilst travelling).
Similarly, our facial cleansers are pH balanced. You’d be surprised how many products aren’t. Clue: making acidic skincare is expensive, cheaper ingredients tend to be non-acidic, aka alkaline.
Our Foaming Face wash is very mild but effective, and works on even the most sensitive skin as we keep hearing from our ‘sensitive testers’. It is a clear gel with a faint orange aroma (from the natural orange water it contains) that mixes with and rinses with water. Unlike harsher soaps, this will clean, remove make up and impurities but not strip the skin off its acid mantle.
If you prefer a creamier product we have our awesome Creamy Cleanser (a favourite of DASH close friends and family), which is a light and oily lotion that melts into skin and rinses off with water like magic, leaving the skin clean, soft and moisturised.
Some of us like to alternative between these two cleansers – using Creamy cleanser when wearing more make up, for example.
FOR BODY AND HANDS we have our liquid Rosemary hand and body wash, which is another firm favorite and can be found in every DASH associates’ kitchen and bathroom. With high quality detergents (and never Sodium Laureth Sulphate), calming Aloe Vera extract and mildly antiseptic essential oils of rosemary and lavender, this wash can be used every day on the whole body by the whole family. We do not recommend this to be used to wash the delicate skin of the face due to its slightly higher concentration of essential oils and detergents. (As faces do not really get dirty in the same was as hands, or feet!)
Of course this wash also has an acidic pH so it will protect your acid mantle whilst providing a good cleanse. Importantly, it is NOT a SOAP. Even if you are not a DASH user, please do not use soap on your body, or especially your face. If absolutely necessary (i.e. they are very dirty) soaps could be used on your hands or feet. Because Soaps Are Always Very Alkaline. Unfortunately, acidic soaps do not exist so they will always disrupt the acid mantle, regardless of how natural, organic, unprocessed or blessed by some deity the ingredients are. This also pertains to liquid soaps made of castile (olive oil-based) or coconut oil etc. If you do love these (and yes, we also grew up with Dr Bronner’s 🙂 ) limit their use and/or follow up with something more pH balanced such as a good quality body/face moisturizer or a Hydrating Face mist.
THE LONG STORY
As you know, both DASH founders are scientists. We like our chemistry. If you, too are so inclined and would like to know more about the chemistry of the acid mantle, read on….
What is a pH anyway?
Well, pH” is a chemist’s term meaning “Potential of Hydrogen”, used to measure the degree of acidity or alkalinity in substances. It is measured on a scale from 0 to 14 where the center of the scale- 7, is neutral (neither acid nor alkaline). A reading below 7 indicates that the substance is acidic, and above 7 is alkaline. The pH system works in 10-fold multiples so each pH unit represents a 10-fold difference in alkalinity. For example, a soap with a pH of 10.5 has 10-times the alkalinity of a soap of pH 9.5.
What is the acid mantle?
Since the early part of 20th century, scientists have known that the outer layers of the skin were acidic and thus termed the “Acid Mantle”. The physiological pH of healthy skin has an average value between 4.5 and 5.9. The acidity of the skin wards off infections by preventing the growth of bacteria and fungi. This is the skin’s first line of defense against microorganisms, atmospheric conditions and various pollutants.
So what is the source of this acid?
The acid mantle is a combination of sebum (oily fats) and perspiration that is constantly secreted to cover the skin’s surface. The mantle contains lactic and amino acids from sweat, fatty acids from sebum (skin wax), and amino acids and pyrrolidine carboxylic acid from the cornification (natural hardening) of the skin. It varies from one part of the body to another and, in general, the pH of a woman’s skin is lower (more acidic) than that of a man’s.
How exactly does it helps to maintain the skin’s strength and integrity?
The acid mantle protects skin in several ways – it acts as an antioxidant, water repellent, bacterial inhibitor and protein hardener.
Antioxidant: the lipids (fats) in the mantle are sacrificially oxidized to protect the underlying skin from excessive oxidation. This is why “whiteheads” – which are un-oxidized sebum in pores – turn into “blackheads” as the sebum is oxidized.
Water repellent: the fats in the mantle repel water from the skin, much as the duck’s feathers oil repels water. This prevents the water from loosening and damaging the skin’s outer layers of hard protective proteins and renders the skin less vulnerable to damage and attack by environmental factors such as sun and wind and less prone to dehydration. So folks, ‘water on skin’ is not always a good thing!
Bacterial inhibition: the acidic pH of the mantle inhibits growth of pathogenic bacteria and fungi growth on the skin. Thus, with a healthy pH (0f 4.5-5.5) the skin remains healthier and has fewer blemishes.
Maintains protein hardness: the outer skin proteins are made of keratin, a very hard protein, which is also used by nature to make horns on animals. Keratin must be kept at an acid pH to maintain its hardness and to keep the protective proteins tightly bound together. Alkaline pH softens and loosens the fibers of keratin and creates gaps in the protective covering. And yes, this eventually potentiates the formation of saggy skin and wrinkles.
What happens when we wash or use alkaline products on our skin?
When we disrupt the acid mantle it creates a susceptibility to bacterial infections, skin damage and disease. This allows more allergens, irritants, bacteria and viruses to penetrate into the skin. Acne, allergies and other skin problems become more severe when the skin becomes more alkaline.
Studies have shown that rinsing the skin with water alone immediately produces a transient increase in pH, and washing the hands with soap bars causes the pH on the palms of the hands to increase by an average of 3 units. This increased pH is not completely normalized as long as 90 minutes after washing with soap. Even the so-called “mild” soaps are often alkaline (pH 9-11) and remove the natural acid protection as well as extract protective lipids (fats) from the skin, strip away the mantle and loosen the protective keratin proteins.
Facial areas are generally not washed as frequently as hands and other areas, but in most cases at least twice a day. Dependent on how alkaline the cleanser is and how healthy the skin is, the return to normal pH can vary between three and fourteen hours (by which time it will be most likely under further assault from another washing!) Continued washing with alkaline substances can effectively strip the acid mantle for up to 16 hours. Extended periods of abnormally high skin pH can affect localized skin health and will encourage abnormal bacterial growth.
Skin that has lost its slightly acidic coat is also prone to dryness, itchiness and wrinkling. Furthermore, irritated and eczematous skins already tend to have a more alkaline pH, and washing with soap can exacerbate this and make the skin even more vulnerable to irritation and infection.
How can we maintain skin pH with good cleansing routine?
Given that the effectiveness of low pH soaps and cleansers has been well documented, one could be forgiven for thinking that home care product manufacturers would meet the market. However, there is a surprising paucity of low-pH soaps and cleansers readily available on our supermarket shelves. Most popular “soaps”, with a few exceptions, are in the pH range of 9 to 10.5. This pH is inherent to the formula, which is usually a sodium salt of fatty acids. Soaps belong to the category of surfactants, together with detergents. Detergents come in all guises, and some (usually more expensive ones!) have a pH around 6. This is why, dear reader, your high-end soapless cleansers rightfully claim to be better for you, albeit at a premium.
Meanwhile, we recommend that after cleansing, even with a neutral or acidic pH cleanser, you use a pH balancing mist (e.g. Hydrating facial mist) to rebalance your skin’s pH before applying on the a moisturiser or a natural oil.