petri dish with white chemical powder

titanium dioxide chemical powder petri dish heap texture inscription banned food additives e171 white pure formula tio2 pw6 77891 oxide coloring catalysts adsorption paints compound alimentary pigment titania phosphonic acid colorants cosmetic ingredient chemistry research nutritional supplement synthetic zinc silica safety products thickener alumina thickening agent carcinogen nano science substance dark background pile dioxide additive e171 paint toothpastes skin care used