Why does “Titanium Dioxide,” a substance found in permanent makeup pigments, pose a risk during laser removal (Q-Switched) procedures?

Titanium dioxide (TiO2) is a white mineral used in permanent makeup pigments (especially light brown eyebrow pigments, skin-toned camouflage pigments, and lipsticks) to lighten the color, achieve pastel shades, and increase coverage. When these pigments are removed with a Q-switched laser, the laser’s high thermal energy instantly removes the oxygen from the titanium dioxide molecules, leading to a chemical reduction. The white substance transforms into a permanent rust black or dark gray within milliseconds (paradoxical darkening). Therefore, chemical removal solutions (removal) should be preferred over laser removal for pigments containing titanium dioxide.