Redseal Hairstyling License Practice Test

An endothermic wave is activated by what duration of time?

1. 5 minutes

2. 10 minutes

3. 15 minutes

4. 20 minutes

The correct answer is: 10 minutes

An endothermic wave, often referred to in the context of perming hair, relies on the application of a chemical solution that produces a reaction to create curls or waves. The key detail here is that this type of wave requires a specific duration for the solution to effectively penetrate and alter the hair's structure. In this instance, a duration of approximately 10 minutes is typically optimal for the endothermic reaction to take place. This time allows the hair cuticle to open and the chemical components to interact with the hair’s disulfide bonds adequately, enabling the desired texture changes without being overly prolonged, which could lead to damage. Other durations like 5 minutes would likely be insufficient to achieve the full effect, and longer times such as 15 or 20 minutes could lead to over-processing, potentially harming the hair. Thus, the 10-minute timeframe strikes a balance between efficacy and safety in the use of endothermic waving solutions.