What chemical process involves breaking down protein structures in hair?

The process of breaking down protein structures in hair is known as chemical relaxing. This technique is specifically designed to change the natural curl pattern of the hair by breaking disulfide bonds within the protein structure of the hair shaft. These disulfide bonds are responsible for the shape and texture of hair, so by chemically altering these bonds, hair can be made straighter and more manageable.

Chemical relaxing products typically contain strong alkaline agents that open the hair cuticle and penetrate the hair shaft, allowing for the alteration of the hair's natural structure. This process can lead to long-lasting changes in the hair, providing a straighter appearance until new hair growth occurs.

In contrast, hair coloring involves the application of dyes that alter hair color but do not fundamentally change the hair's structure. Thermal curling involves using heat tools to create curls by temporarily altering the shape, and hair straightening, while it can also temporarily change the appearance of the hair, typically involves the use of heat as well rather than a chemical alteration of the structure.