The EU expert panel did not identify an immediate health concern linked to TiO2 when used as a food additive. However, due mainly to uncertainties concerning the safety of TiO2 nanoparticles, the panel concluded that TiO2 as a food additive (E171) could no longer be considered safe.
2. Relative density: 4.136 to 4.39 g/mL.
2. Barite calcination method A solution of barium sulfide is prepared. The sulfuric acid and zinc oxide are reacted, purified by adding potassium permanganate and zinc powder, and compressed to obtain a zinc sulfate solution. Then, the prepared barium sulfide solution is mixed and subjected to a metathesis reaction to obtain a mixture of zinc sulfide and barium sulfate, and then the precipitate is subjected to pressure filtration, calcination, wet grinding, drying, and pulverization to obtain a zinc white product.