Although the evidence for general toxic effects was not conclusive, on the basis of the new data and strengthened methods we could not rule out a concern for genotoxicity and consequently we could not establish a safe level for daily intake of the food additive, commented Matthew Wright, member of the EFSA's Food Additives and Flavourings Panel in a press statement.

The FDA first approved the use of titanium dioxide in food in 1966, following its 1960 removal (along with the removal of other color additives) from the agency's original Generally Recognized as Safe list. In 1977, titanium dioxide joined the list of color additives that are exempt from certification, which means titanium dioxide doesn't have to be listed on the packaging of every product it's used in, Faber noted.

Lithopone is a mixed zinc sulfide-barium sulfate brilliant white pigment that contains about 30% zinc sulfide. The original light sensitiveness of this pigment has been mitigated by purification and by the addition of such agents as polythionates and cobalt sulfate.

Certificate of Analysis (Lithopone B301, Lithopone B311 powder TDS)

The production of ROS was studied on white blood cells as a model to screen the effect on eukaryotic cells after being exposed to samples and solar simulated irradiation (according to the level of penetration under the skin). For that purpose, the leukocytes were separated from anticoagulated fresh blood using the Ficoll-Hypaque reactive in a well-known technique [33]. Then, 50 μL of suspensions of P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL), vitaminB2@P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL) and vitamin B2 (0.2 mg/mL and 0.02 mg/mL) were prepared and mixed with 50 μL of white blood cells suspension. A solution of 3% H₂O₂ was used as positive control and PBS as negative control. Then, the samples were irradiated using the LED panel for 3 and 6 h to simulate the light penetration into the skin. Also, a set of samples was kept in the dark as control. Finally, the ROS were detected through the colorimetric assay employing the nitroblue tetrazolium salt (NBT salt) and the absorbance at 650 nm was measured. The experiment was reproduced twice; the standard deviation was calculated and p-value < 0.05 were considered significant.

Following the filtration, the precipitate is washed thoroughly to remove any impurities and excess reagents. This is a crucial step, as thorough washing ensures that no contaminants interfere with the final mass measurement. Once washed, the precipitate is dried in an oven at a controlled temperature to remove moisture, ensuring that the mass recorded reflects only the titanium content.

Lithopone is a white pigment (PW5) co-precipitated from solutions of zinc and barium salts according to the following reaction: 

Titanium dioxide manufacturer: Yuxing