A Comparative Study on Frizz Hair Formation and Lightness Variation by H2O2 Concentration and Repetition in Thermal and Non-Thermal Bleaching: A Management Approach in the Context of Beauty Service Practice

This study was conducted from the perspective of risk management and customer satisfaction enhancement in beauty service practices to analyze the structural damage to hair caused by repeated thermal bleaching. The experiment involved varying concentrations of hydrogen peroxide (H2O2) (3%, 6%, 9%) and applying repeated bleaching treatments to Human Hair Tresses (HHT) under both non-thermal and thermal conditions. As a result, hair lightness increased with the number of bleaching sessions, and the rate of lightness change was notably accelerated under thermal conditions. In particular, 9% H2O2 under thermal treatment achieved platinum blonde levels after only one to two sessions. Frizzy hair was not observed under non-thermal conditions regardless of H2O2 concentration or repetition. However, with 9% H2O2 under thermal bleaching, frizz and hair volume expansion began to appear from the third session, and the condition worsened noticeably after the fifth session. Permanent wave patterns deteriorated progressively with repeated bleaching, especially under thermal conditions. These results suggest that high-concentration H2O2 and heat synergistically accelerate cuticle damage and cortical collapse, potentially leading to not only physical deterioration but also psychosocial crises. Therefore, in order to ensure safe beauty service practices, it is essential to implement pre-treatment risk disclosures and establish protective care programs.