What is significant about the 428 nm wavelength in hair lightening?

The significance of the 428 nm wavelength in hair lightening lies in its ability to effectively break down melanin, the pigment responsible for hair color. When light energy within this specific wavelength range is applied to the hair, it interacts with the melanin molecules, causing them to decompose. This process is essential in the hair lightening procedure, as it allows for the gradual lightening of the hair by reducing the concentration of color pigments.

The precise wavelength of 428 nm is effective because it corresponds to the energy levels required to target and disrupt the bonds within the melanin structure without causing excessive damage to the hair's natural proteins. This selective interaction makes it a key aspect of formulated lightening agents and techniques used in cosmetology to achieve a lighter hair color without compromising the integrity of the hair.

In contrast, the other choices do not relate directly to the chemical process of hair lightening through melanin decomposition. Promoting hair growth, enhancing shine, and influencing hair texture are not connected to the specific actions that occur at the 428 nm wavelength during the lightening process.