This Chemistry and Ingredient Handbook has been compiled in order to address what may be perceived as a "hole" in the available information for our skin care industry. Although there are a number of excellent ingredient dictionaries available, I have heard from many professionals who have wanted significantly more information about newer research on previously termed ?old fashioned? ingredients than they were able to find in current ingredient dictionaries. Amazingly, much of the new ingredient technology in our industry is based on plants that have been used for centuries as homeopathic remedies for physical ailments. The ?high tech? ingredients currently being researched and produced are uniquely biotech and also aim to repair skin damage, not just slow down the appearance of aging. In researching for this handbook, I utilized many resources, including the internet, libraries, chemistry professors, biochemical engineers, and cosmetic chemistry professionals from many manufacturers. As with any informational writing, the reader is advised to review their protocols on a regular basis and to make modifications based upon the skin response of their clients, new information presented by other educational resources and product usage. The esthetic professional who continues to undertake advanced training knows that we can no longer rely on conventional facial treatments alone to assist in improving our client?s skin condition. Educating our clients, in addition to ourselves, is one way to provide accurate and reliable information regarding the types of treatments we perform and how they can affect each individual?s skin condition. This handbook is divided into a text section with documentation on Antioxidants, Cosmeceuticals, Exfoliants, Moisturizers, Peptides, Teleomeres, etc. I have made major revisions from the 2005 edition by adding a separate chapter entitled ?Ingredient Descriptions,? and to facilitate easy location of a particular ingredient, all ingredients are listed in this chapter alphabetically. For many of the ingredients listed, you will note a ?CAS Number? associated with the entry. These are numbers supplied by the American Chemical Society, and are identified as the Chemical Abstracts Service Registry Number. These numbers do not provide data about the strength of an ingredient, but simply identification for reference to locate the MSDS, or other informational listings, such as the National Institute for Standards and Technology (NIST) Chemistry Web book.