interact with and affect the cells in the human body. The best and most straightforward way to do this is to learn about pH
levels within the body, which provides applicable insight into how our bodies interact with different chemical components.
THE PH BALANCE
What is pH? We have discussed several different chemical elements, such as oxygen (O), Carbon (C), and Hydrogen (O), but the acronym “pH” is much different. Rather than a symbol used for an element (no, pH does not stand for phosphorous, which is denoted as “P”), pH is actually an abbreviation for “power of hydrogen,” where “p” is short for “potenz” or the German word for power, and H is the element symbol for hydrogen. pH can be defined as the negative log of hydrogen ion concentration in a water-based solution. Based on a logarithmic scale that runs from 0 to 14, pH levels indicate the acidity or basicity (alkalinity) of a substance compared to that of pure water (which has a pH level of 7). Any substance with a pH value below 7 is ten times more acidic than the higher value, and each whole pH value above 7 is ten times less acidic than the one below it. A pH of 7 is neutral (pH of pure water). Acidic and basic are two extremes that describe chemicals, just like hot and cold are two extremes that describe temperature. Mixing acids and bases can cancel out their extreme effects, much like mixing hot and cold water can even out the water temperature. A substance that is neither acidic nor basic is neutral. When chemicals are mixed with water, the mixture can become either acidic or basic. Vinegar and lemon juice are acidic substances, while laundry detergents and ammonia are basic. pH Value
The average hair, skin, and nails have a pH level of 5, generally falling between 4.5 and 6 . However, this is not a true indicator of pH for these components of the Integumentary System due to a protective film of oily acidic secretion that coats and lubricates the surface of the skin and scalp. This combination of oils and water-soluble materials is referred to as our acid mantle. The acid mantle is produced by the skin and protects the hair, skin, and nails from outside elements and chemicals. The pH level of the acid mantle in various parts of the body tells a great deal about the health of our Integumentary System and gives insight into the cosmetic procedures that would be helpful for a particular individual . For example, the average pH on the surface of the scalp is 4.8; yet, as we measure the pH on the hair at further distances from the scalp, the pH value increases. This shows that less of the acid mantle reaches the ends of longer hair, meaning the ends of the hair are less protected than hair closer to the roots. The scalp’s oils keep the hair lubricated and shiny, while its acidity keeps the fiber compact and strong. This is why it is necessary to apply increased products to the ends of the hair, in order to maintain the shine and strength. For weak or damaged hair, it may be appropriate to use products with higher acidity and increased moisture. Finding products with a pH that is compatible with a person’s natural biology is essential to proper cosmetic care. Due to the bodies’ natural chemistry, products with a pH of 4.5 to 5.5 are compatible with the natural biology of the skin and scalp, whereas higher pH levels are incompatible and can have a drying effect . These products maintain a mildly acidic environment that closely resembles the environment of our acid mantle. We call these products “acid balanced.” This is important to note because when high pH (basic)
Acidity or alkalinity compared with pure water
Acidic 0
10,000,000 1,000,000
1 2 3 4 5 6
100,000 10,000
products come in contact with the hair, the solution is absorbed through the cuticle layer into the cortex layer of the hair. This imbalance of pH causes the hair to swell, which forces the cuticle layers to be stretched. This puts the hair into an unnatural state and, more often than not, causes breakage. For example, washing a person’s hair with baking soda may clean it thoroughly, but the high pH level (8.1) indicates it is very alkaline and will have a drying effect on the hair. At the same time apple cider vinegar has a much more
1,000
100
10
Neutral 7 (pure water)
1
8 9
10
100
10 11 12 13
1,000
10,000 100,000
1,000,000 10,000,000
Alkaline 14
Chemicals that are very basic or very acidic are called “reactive. ” These chemicals can cause severe burns. For example, automobile battery acid is an acidic chemical that is reactive and a stronger form of some of the same acid that is in acid rain.
• The average hair,
skin, and nails have a pH level of 5, falling between 4.5 and 6 .
acidic pH, somewhere between 2.8 and 3.0, making it more potent in maintaining a healthy pH in the body by restoring alkaline acid balance. Therefore, it is often used as a conditioner for extremely dry, alkaline hair. The most effective cosmetic products (i.e., shampoos, conditioners, hair colors, tints, etc.) will have the right level of pH (4.5 to 5.5). Chemists have found that most ingredients work best at a specific pH balance. There are some chemical services used in cosmetology that require a high pH to work properly.
• Products with a pH of 4.5 to 5.5 are
compatible with the natural biology of the skin, hair, and nails.
Household drain cleaners are also reactive due to the presence of lye, an extremely alkaline chemical. Obviously, these reactive chemicals are harmful to the human body and can cause damage to the skin, hair, and nails. Those chemicals that are neutral, such as pure water, have little if any negative impact.
Page 17
Book Code: EFL1024
EliteLearning.com/Cosmetology
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