Which of the following is the active ingredient or reducing agent in alkaline permanent waves?

• A. Hydrogen peroxide
• B. Sodium hydroxide
• C. Ammonium thioglycolate
• D. Calcium carbonate

Answer: (C)

Verified step by step guidance

1. Understand the context: In alkaline permanent waves (used in hair treatments), the active ingredient is responsible for breaking disulfide bonds in hair proteins, allowing the hair to be reshaped.
2. Identify the role of each compound: Hydrogen peroxide is an oxidizing agent, sodium hydroxide is a strong base used to raise pH, calcium carbonate is often a buffering agent, and ammonium thioglycolate is known for its reducing properties.
3. Recall that a reducing agent donates electrons to break disulfide bonds (S-S) in keratin, which is essential for the perming process.
4. Recognize that ammonium thioglycolate acts as the reducing agent by breaking these disulfide bonds, enabling the hair to be reshaped before the bonds are reformed.
5. Conclude that ammonium thioglycolate is the active ingredient or reducing agent in alkaline permanent waves.