Which chemical is most commonly used in permanent waving solutions?

The most commonly used chemical in permanent waving solutions is ammonium thioglycolate. This compound is a关键 ingredient in perm solutions because it breaks the disulfide bonds in the hair's protein structure, particularly keratin, allowing it to be reshaped into curls or waves when combined with heat and time.

Ammonium thioglycolate works by reducing the hair's pH, which is critical for the perm process as it softens the hair and makes it pliable. This is essential for successfully creating the desired curl pattern, and it provides a balance between effectiveness and hair health when applied correctly.

Other chemicals mentioned, such as hydrogen peroxide and sodium hydroxide, have different applications in hair treatments. Hydrogen peroxide is primarily used as a bleaching agent and for oxidation in hair coloring processes, while sodium hydroxide is a strong alkaline chemical with a different use in hair straightening systems. Calcium hydroxide is not typically found in perm solutions but may be involved in other types of hair treatments. Therefore, the focus on ammonium thioglycolate aligns closely with its established role in the perming process.