Unlike Thio neutralization, the neutralization process of hydroxide relaxers does not involve which process?

• A. Oxidation
• B. Reduction
• C. Hydrolysis
• D. Dehydration

Answer: (A)

The action being tested is what happens during the neutralization step. In thio-based relaxers, the hair bonds are first reduced to break disulfide bonds, and the neutralizer then oxidizes the resulting thiol groups back into disulfide bonds. That oxidation step is essential to re-form the cross-links and set the new straight shape. In contrast, hydroxide relaxers rely on the high pH to break bonds through alkaline hydrolysis, and the neutralization simply brings the pH back to normal without introducing an oxidizing step to reform disulfide bonds. So oxidation isn’t involved in the neutralization of hydroxide relaxers.

Reduction is involved earlier in thio processing, not in the hydroxide neutralization. Hydrolysis occurs under the strong basic conditions of hydroxide relaxers, but not as part of the neutralization step. Dehydration isn’t a primary mechanism in these neutralization chemistries.