Which chemical is primarily used in relaxing treatments?

Sodium hydroxide is primarily used in relaxing treatments due to its strong alkaline properties, which facilitate the process of breaking down the disulfide bonds in curly or wavy hair, allowing for a smoother and straighter texture. It is commonly found in products designed for hair relaxing because it effectively alters the hair's structure through its high pH level, enabling easy manipulation of hair into a desired shape.

In the context of chemical relaxation, sodium hydroxide is particularly notable for its effectiveness in treating coarse and resistant hair types, which can be challenging to relax with milder agents. The relaxed hair strands result from the chemical's action on the protein structure of the hair, making it a preferred choice among professional stylists for achieving long-lasting straightening results.

While other chemicals mentioned have their specific uses, their roles differ from the primary function of sodium hydroxide in hair relaxing treatments. Each of those chemicals has applications, but sodium hydroxide's potency and capacity to provide significant changes to the hair structure distinguish it in this context.