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.

On the other hand, the U.S. Food and Drug Administration (FDA) in their Final Administrative Order on Sunscreen Drug Products posted in September 2021 still accepts titanium dioxide up to 25% in the list of Generally Recognized As Safe and Effective (GRASE) in the main document, without further clarification on what kind or size of particles [9]. However, on page 24 (Sunscreen containing nanomaterials) FDA clearly “distinguish nanomaterials from other forms of these ingredients'' (zinc oxide and titanium dioxide) and ask for comments on “any particular nanomaterials that you believe should not be permitted for use in OTC sunscreen products”. To the best of our knowledge, this Agency did not ban the use of nanoparticulate titanium dioxide in any form, even though it is mentioned on page 34 that the anatase form is the more photoactive one, due to the lack of evidence with real sunscreens OTC (over the counter) in vivo. Moreover, other regulations in Latin America (MERCOSUR agreement, 2006) do not state clearly their position on the use of nanoparticulate TiO₂NPs [10].

1. Sheet iron method

Yesterday, the domestic rutile type, anatase titanium dioxide new single price stability, the market overall transaction focus moved up. Titanium dioxide factory work normally, more delivery of early orders, less spot supply; And buyers still have inventory digestion, the current mentality turned to wait-and-see. The volume of new orders in the market is limited.The key factors affecting the current market price change1. Inventory: the mainstream manufacturer inventory is low, there are still early delivery orders, it is expected that today's spot inventory is still low, and the mainstream factory spot is tight.

The Evolution and Impact of Anatase Titanium Dioxide Manufacturers

For research published in Archives of Toxicology in 2020, scientists fed one group of mice a solution containing titanium dioxide for one month, and compared it to those that did not receive the additive. They found “the richness and evenness of gut microbiota were remarkably decreased and the gut microbial community compositions were significantly changed” in the titanium dioxide group when compared with the control group. The tests also revealed that the titanium dioxide exposure could cause locomotor dysfunction, or mobility issues “by elevating the excitement of enteric neurons, which might spread to the brain via gut-brain communication by vagal pathway.” The researchers concluded: “These findings provide valuable insights into the novel mechanism of TiO2NP-induced neurotoxicity. Understanding the microbiota-gut-brain axis will provide the foundation for potential therapeutic or prevention approaches against TiO2NP-induced gut and brain-related disorders.”

Topical Exposure 

5. Regulatory compliance The MSDS should also include information on regulatory requirements for the safe handling and use of lithopone, including any permits or certifications that may be necessary.

How can I tell if a product has titanium dioxide in it? How can I avoid the ingredient?

A legal additive in the United States, titanium dioxide is used in everything from food to consumer goods and the U.S. Food and Drug Administration says regulated use of the product as a color additive in food is safe within certain restrictions.

Panzhihua Dongfang Titanium Industry Co., Ltd. Dongfang, a well-known brand of titanium dioxide, a famous brand in Sichuan, a high-tech enterprise, a large supplier of titanium dioxide and titanium sponge, and one of the largest/leading titanium raw material production bases in China.

The raw material used in this method is FeSO4. In order to maintain the Fe3 + concentration in the reaction medium in a specific range, reducing agent iron sheet is added in the reaction process. Iron yellow crystal seed was added and air was introduced to synthesize iron yellow under certain pH conditions. The method mainly includes two steps: (1) firstly, FeSO4 · 7H2O is used as raw material, NaOH or NH3 · H2O is used as precipitant or pH regulator, and air is used as oxidant to prepare crystal seed; (2) Iron yellow is produced by two-step oxidation with crystal seed, FeSO4, iron sheet and air.

Although food-grade titanium dioxide must be 99 percent pure, there’s still a risk of it containing potential contaminants, such as mercury, lead and arsenic. Additionally, inhaling the mineral over time can possibly cause it to build up in your body, leading to adverse effects.