What is a common cause of hair damage during perm application?

During perm application, improper application of chemicals or excessive heat is a common cause of hair damage. This is because the chemicals used in perming processes are designed to alter the hair's structure. If these chemicals are not applied correctly—whether in terms of saturation, timing, or the order of operations—they can cause the hair to become overly processed, leading to dryness, brittleness, and breakage.

Additionally, excessive heat from tools can exacerbate the effects of the chemicals, further weakening the hair structure. This combination can ultimately compromise the integrity of the hair, resulting in significant damage. Proper technique is crucial to ensure that the hair remains healthy and is able to withstand the chemical changes introduced during the perming process.

In contrast, choices involving over-conditioning, wrong rod size, and shampooing afterward do not directly affect the perm process in the same detrimental manner, making them less significant causes of damage.