Which ingredient is commonly used in hair color activators to speed up the decolorization process?

The ingredient commonly used in hair color activators to speed up the decolorization process is persulfate. Persulfates are oxidizing agents that release oxygen and help to break down the natural pigment in the hair. When added to hair coloring formulations, persulfates enhance lightening and are effective in accelerating the decolorization process, making them a popular choice in many hair color products.

While hydrogen peroxide is also an oxidizing agent and plays a crucial role in hair dye formulations, especially for developers, its primary function is to oxidize the coloring agents rather than specifically serve as a decolorization accelerator. On the other hand, ammonia is used to raise the pH of the hair, allowing for cuticle lift and penetration of the dye, but it doesn't directly enhance the decolorization process like persulfates do. PDG (p-phenylenediamine) serves as a dye precursor and is not intended for decolorization. This makes persulfate the ideal answer in this context.