Mehndi Henna Indian Tattoos

The term henna tattoo is figurative, because true tattoos are permanent surgical insertions of pigments underneath the skin, as opposed to pigments resting on the surface as is the case with mehndi.
Likely due to the desire for a "tattoo-black" appearance, many people have started adding the synthetic dye p-Phenylenediamine (PPD) to henna to give it a black colour. PPD is extremely harmful to the skin and can cause severe allergic reactions resulting in permanent injury or death. Alata (Mahur) is a flower-based dye used to paint the feet of the brides in some regions of India. It is still used in Bengal.