This problem set is the definitive guide for those aiming to pass the Cosmetics Ingredient Certification Level 2 exam, featuring a carefully selected 200 questions. Detailed answer explanations are provided for all questions, based on the structure and mechanism of action of the raw materials, allowing you to cultivate "ingredient analysis skills" as a beauty and cosmetics professional. ■ Contents of this book • Chapter 1: Oily Ingredients (Questions 1-40) Characteristics and feel of hydrocarbons (vaseline, mineral oil), higher fatty acids, higher alcohols, oils (vegetable oils), ester oils, and silicone oils. • Chapter 2: Surfactants (Questions 41-70) Structure and properties of anionic, cationic, amphoteric, and nonionic surfactants. Comparison of skin irritation strength, emulsification, and cleaning mechanisms. • Chapters 3-4: Moisturizing Ingredients & Quality Preserving Ingredients (Questions 71-110) Water-soluble moisturizing ingredients (glycerin, BG, hyaluronic acid), ingredients that support barrier function (ceramides), preservatives (parabens, phenoxyethanol), and the role of antioxidants. • Chapters 5-6: Functional Ingredients & Others (Questions 111-160) Active ingredients for whitening, wrinkle improvement, anti-inflammation, etc., the difference between UV absorbers and scattering agents, thickeners, and pH adjusters. • Chapter 7: Full Ingredient Labeling & Comprehensive Questions (Questions 161-200) Principles of labeling rules (e.g., in order of amount), carry-over ingredients, the definition of alcohol-free, and inference of product characteristics from ingredient lists. ■ Features of this book • Logically organizes "surfactant irritation" The order of irritation frequently tested in the exam, "cationic > anionic > amphoteric > nonionic," is explained in detail along with the structural reasons. • Covers the proper use of "similarly named ingredients" Provides comparative explanations to strengthen your ability to answer tricky questions about ingredients with similar names but completely different properties, such as the difference between "ethanol" and "behenyl alcohol." • Enhances the ability to read "full ingredient labeling" Practical exercises are possible to anticipate actual label notations and identify which ingredients are the main components and which are added for stabilization.