Which statement about the chemical steps in a permanent wave is correct?

• A. The neutralizer continues the processing to break more bonds.
• B. The reducing step uses oxidizing agents.
• C. The oxidizing step breaks disulfide bonds.
• D. Reducing agents break disulfide bonds, and oxidizing agents in the neutralizer re-form them.

Answer: (D)

Permanent waving relies on two chemical steps that reshape the hair: first, a reducing agent breaks the disulfide bonds that hold the hair’s original shape, turning those cross-links into free thiol groups so the hair can be set into a new form. Then an oxidizing step re-forms those bonds, locking in the new curl by converting the thiols back into disulfide bonds. This is why the statement is correct: reducing agents break disulfide bonds, and oxidizing agents in the neutralizer re-form them. The neutralizer’s job isn’t to keep breaking bonds; it’s to re-create the disulfide links in the new shape.