Do you know the chemical consequences of the shampoos, conditioners and treatments you are using on your clients? Knowing the correct products to use on different types of hair will allow stylists to make product decisions with greater confidence. The following article was taken from a presentation by Kevin Anthony and Jakki Dee at the Proud Lady Beauty Show - Chicago.

The main job of any shampoo, whether liquids, gels or creams, is to remove the dirt, oils and pollutants in the hair and to cleanse the scalp. Shampoos usually contain several ingredients such as detergents, foaming agents, conditioners and additives. The most important ingredient is the cleansing agent, known as the detergent. Synthetic detergents are used because they lather better than soap, especially in hard water, which contains relatively large amounts of calcium. The main advantage of expensive synthetic detergent shampoos is they have the ability to grab hold of oils and greases, while attracting water to rinse them away. Foaming agents act with the detergent and water to help float the dirt away. Conditioners replace some of the natural oils, reduce tangling and make the hair shinier and easier to comb. Additives are put in shampoo to meet a particular need, such as to control dandruff.

The pH of a shampoo has become an important factor in selecting the right shampoo for the right type of hair. pH refers to the acidity or alkalinity of a particular solution. The number of hydrogen (H+) ions determines the pH. A high concentration of H+ ions, with a higher concentration of hydroxide (OH-) ions, changes the solution toward alkalinity. The scale of pH is measured between 0 and 14. A neutral solution, one that is neither acidic nor alkaline has a pH of 7. Water is an example of a neutral solution. Solutions with a pH greater then 7 are acidic. Acetic acid (vinegar), solutions of carbon dioxide (substance found in soda), and hydrochloric acid (HCI) are examples of acidic solutions. Solutions with a pH greater than 7 are alkaline, such as sodium bicarbonate (baking soda), soaps and sodium hydroxide (lye), which is strongly alkalotic. The table (see below) gives a complete list of the pH of various substances and solutions.

There is a thin film of moisture normally present on the hair follicles and scalp. When measured electromagnetically, the moisture is found to be mildly acidic, with a pH between 4.5 and 5.5. This protective film of moisture is called the acid mantle of the hair. This natural moisture gives hair roots and the scalp its slightly acidic nature, which helps the hair shaft maintain its resliancy, strength and outer coat.

Shampoos show a wide range in pH, varying from 4 - 10; with pH 4.5 - 5.5 acidic, pH balanced at seven and from pH 7.1 to alkaline. Manufacturers rarely list the pH of the shampoo or conditioner on the bottle, but it can be found by calling the toll-free number listed on the labels or by doing a home test with acid-base indicators, such as Nitrazine paper. Soaps are much more alkaline than shampoos, with pH 10 or 11, which is why they should not be used on hair.