What is the minimum particle size? April 14, 2021 13:57 Updated Titanium and Zinc oxide are uncoated and have a minimum particle size of 0.1 microns. Related articles Do you use any nano or micronized particles? What is the exact size of the Titanium Dioxide particles in the powder foundation? What testing do your ingredients go through (specifically titanium dioxide, iron oxides, zinc oxides, and mica)? How do I wash my Lily Lolo brushes? Are your products comedogenic?