What is the approximate pH level of on-the-scalp lighteners?

On-the-scalp lighteners typically have a pH level that is around 9.0. This higher pH is necessary as it helps to open the hair cuticle, allowing the lightening agents to penetrate the hair shaft more effectively. Lighteners must provide a suitable environment for the chemical reactions that occur during the bleaching process, and a pH of 9.0 facilitates that by creating alkaline conditions that are essential for the activation of hydrogen peroxide and other lightening agents within the formula. This level is specifically formulated to ensure that the hair can be lifted while minimizing damage to the scalp, making it a common choice among hairstylists for achieving lighter hair colors safely.