For this 3rd edition of Hairdressing Science the text has been completely reviewed and updated to follow the scheme set out by the Hairdressing Training Board for the National Vocational Qualifications Level 2 in Hairdressing. A change of emphasis reflects the growing concern for the safe use of chemicals and the assessment of health hazards. Throughout the book students are alerted to the effects of the misapplication of chemical products and the misuse of appliances.