Schwarzkopf BC Bonacure Sulfate-Free Micellar Shampoo pH 4.5 Color Freeze 33.8 Ounce 1000 Milliliters Schwarzkopf Professional BC BONACURE pH 4.5 Color Freeze Sulfate-Free Micellar Shampoo is a gentle formula for coloured hair that effectively cleanses and helps to optimise the pH level to 4.5. This shampoo provides protection to the hair structure, stabilises and tightens the hair matrix and also helps prevent colour fade.