Adhesion Failure of External Hair Cuticles Caused by Prussian Blue: Possible Electrochemical Roles of Sulfur and Cystine

The study investigated the effects of Prussian Blue (PB) on human hair fibers using a new optical microscopy technique. Freshly plucked and aged hair samples were exposed to a 2.5% potassium ferrocyanide solution, and the results showed that PB caused significant separation of the cuticle segments from the hair shaft. This adhesion failure was observed intermittently along the hair length and was hypothesized to result from an electromagnetic reaction between PB and the sulfur and cystine in the hair. The study concluded that PB exposure leads to cuticle detachment, potentially impacting hair integrity.