Skin whitening cells causes the skin to naturally regenerate itself. Excess melanin comes to the surface and peels off in a few days. This is particularly useful in sensitive areas like the genitals where laser treatment could leave a scar. Efficacy of the treatment depends on the depth of the pigment. There is evidence to suggest that some types of skin-whitening products use active ingredients, such as mercurous chloride and hydroquinone, which can be harmful. Hydroquinone is not available without a prescription in Europe. It is only available when prescribed by a medical doctor (e.g. a general practitioner). This is also the
Pigment chemicals also have their own reflection and absorption patterns, which can affect the final spectrum. For example, in pigment/binder mixtures, individual rays of light may not encounter pigment molecules and may be reflected unchanged. These stray rays of source light make the mixture appear to have a less saturated color. Pure pigment allows very little white light to escape, producing a highly saturated color, while a small quantity of pigment mixed with a lot of white binder will appear unsaturated and pale due to incident white light escaping unchanged. Naturally occurring pigments such as ochres and iron oxides have been