Which perms are self heating and self timing?

Which perms are self heating and self timing?

• A. Acid perms
• B. Alkaline perms
• C. Exothermic perms
• D. Low/no Thio perms

Answer: (C)

Exothermic perms generate heat as the chemical reaction unfolds, warming the processing solution and the hair. That self-generated heat speeds up the breaking and reforming of disulfide bonds, so the hair changes occur more quickly without needing external heat. Because the heat itself drives the process, you can gauge timing by how the temperature rises and the hair’s condition rather than sticking to a strict clock. That’s why this type is described as self heating and self timing. The other perm types typically rely more on a set processing time with external heat control, rather than producing heat themselves.

Exothermic perms generate heat as the chemical reaction unfolds, warming the processing solution and the hair. That self-generated heat speeds up the breaking and reforming of disulfide bonds, so the hair changes occur more quickly without needing external heat. Because the heat itself drives the process, you can gauge timing by how the temperature rises and the hair’s condition rather than sticking to a strict clock. That’s why this type is described as self heating and self timing. The other perm types typically rely more on a set processing time with external heat control, rather than producing heat themselves.