The most comprehensive source on the subject, this Second Edition is completely revised and expanded to reveal the most recent advances, technologies, and trends in hair and hair care science-tracking the development of hair care products, the emergence of new regulatory practices, and the latest methods in product safety and efficacy assessment. The most comprehensive source on the subject, this Second Edition is completely revised and expanded to reveal the most recent advances, technologies, and trends in hair and hair care science-tracking the development of hair care products, the emergence of new regulatory practices, and the latest methods in product safety and efficacy assessment. The most comprehensive source on the subject, this Second Edition is completely revised and expanded to reveal the most recent advances, technologies, and trends in hair and hair care science-tracking the development of hair care products, the emergence of new regulatory practices, and the latest methods in product safety and efficacy assessment. The most comprehensive source on the subject, this Second Edition is completely revised and expanded to reveal the most recent advances, technologies, and trends in hair and hair care science-tracking the development of hair care products, the emergence of new regulatory practices, and the latest methods in product safety and efficacy assessment. The most comprehensive source on the subject, this Second Edition is completely revised and expanded to reveal the most recent advances, technologies, and trends in hair and hair care science-tracking the development of hair care products, the emergence of new regulatory practices, and the latest methods in product safety and efficacy assessment. The most comprehensive source on the subject, this Second Edition is completely revised and expanded to reveal the most recent advances, technologies, and trends in hair and hair care science-tracking the development of hair care products, the emergence of new regulatory practices, and the latest methods in product safety and efficacy assessment.