Scrap zinc or concentrated zinc ores are dissolved in sulfuric acid, the solution is purified, and the two solutions are reacted. A heavy mixed precipitate results that is 28 to 30% zinc sulfide and 72 to 70% barium sulfate.

All samples (n = 6) were irradiated in a 96 well plate using an LED panel on top for 3 and 6 h before analysis. An identical set of samples were kept in the dark as controls. The temperature was checked and did not go over 37 °C. The intensity of light was also measured and was constant at 19,500.10 lux. (43.33 W in 0.2 m²), about 5 times less than actual solar light intensity on Earth's surface Therefore, these findings are indicative of even greater danger in real life.

Titanium dioxide is used in an enormous range of food products, which can feel jarring when looking at some of its other uses.

Here it has been shown that functionalization of P25TiO2NPs with vitamin B2 was able to significantly decrease the oxidative stress produced when they are exposed to sunlight. This finding is of main importance to prevent skin damage and toxicity of sunscreens containing this form of untreated titanium dioxide and should be taken into consideration when updating the regulations mentioned above .

Lithopone