Name a commonly used chemical in hair straightening services.

Sodium Hydroxide is a commonly used chemical in hair straightening services, particularly in relaxers for very curly or textured hair. This chemical acts as a strong alkaline agent that works by breaking down the bonds in the hair structure, allowing for a change in the hair's natural curl pattern. Its effectiveness makes it a popular choice among professionals for achieving sleek, straight hair.

In hair straightening treatments, particularly those for extremely curly hair, Sodium Hydroxide can be applied to achieve a significant change. It is essential to use this chemical with caution, as it can cause damage if left on the hair for an extended period or if not applied properly. Regular consultations and patch tests are crucial to ensure safety and effectiveness when using such strong chemicals.

Other chemicals mentioned serve different purposes; for instance, Hydrogen Peroxide is typically used as a bleaching agent and is not a primary component in straightening services. Ammonium Thioglycolate is used in perming and waving solutions rather than straightening, while Formaldehyde is associated with certain keratin treatments but is not commonly recognized as a standard ingredient in traditional hair straighteners.