Illinois Cosmetology Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

The two procedures that should never be performed on the same day are a chemical relaxer and a perm. This is because both treatments use strong chemicals that can alter the hair's structure, but in opposite ways. A chemical relaxer straightens the hair by breaking down the bond structure, while a perm creates curls by reforming these bonds. Performing both procedures consecutively could significantly weaken the hair, lead to excessive damage, and increase the risk of breakage. It's crucial to allow hair to recover from one chemical treatment before applying another that alters its structure, ensuring healthier results and minimizing harm to the hair.

Haircut and color, shampoo and conditioning, and bleaching and toning, while they may require caution or specific timing, do not pose the immediate risks associated with combining a chemical relaxer and a perm, making them safer to perform on the same day when properly managed.