What was the active ingredient used in the first cold wave?

What was the active ingredient used in the first cold wave?

• A. Thioglycolate acid or derivative
• B. Ammonium thioglycolate
• C. Sodium hydroxide
• D. Urea

Answer: (A)

The main idea here is the reducing agent that actually breaks the hair’s disulfide bonds so it can be reshaped in a cold wave. In the very first cold-wave formulas, the active ingredient was thioglycolic acid or a derivative of it. This compound reduces those bonds at room temperature, allowing the hair to be wrapped on rods and reformed into a curl without applying heat. Ammonium thioglycolate is just a later form of the same chemical family—a salt that improved stability and handling in many modern perms—but the original cold wave used thioglycolic acid or its derivative. Sodium hydroxide and urea aren’t the reducing agents that do the disulfide-bond breaking in this process, so they aren’t the correct active ingredient for the first cold wave.

The main idea here is the reducing agent that actually breaks the hair’s disulfide bonds so it can be reshaped in a cold wave. In the very first cold-wave formulas, the active ingredient was thioglycolic acid or a derivative of it. This compound reduces those bonds at room temperature, allowing the hair to be wrapped on rods and reformed into a curl without applying heat.

Ammonium thioglycolate is just a later form of the same chemical family—a salt that improved stability and handling in many modern perms—but the original cold wave used thioglycolic acid or its derivative. Sodium hydroxide and urea aren’t the reducing agents that do the disulfide-bond breaking in this process, so they aren’t the correct active ingredient for the first cold wave.