Titanium Dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula TiO 2. When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891
In the United States of America (USA), instead of considering the carrier substrate PAS and the color titanium dioxide separately, the compound pigment itself, under the name mica-based pearlescent pigments, is regulated under 21 Code of Federal Regulations (CFR) 73.350.
Under the guiding principles that specifications are intended to apply to the additive as marketed and used in food, as well as represent the substance for which toxicological testing was performed, the 74th JECFA decided to prepare separate specifications for both PAS as well as the actual compound pigment.
http://www.fao.org/fileadmin/user_upload/agns/pdf/CTA_MICA_77.pdf
https://en.wikipedia.org/wiki/Titanium_dioxide