if you compare the levels—which went as high as 50,000 milligrams/killigrams per day— to what humans are actually exposed to, we're talking orders of magnitude. It was a huge amount, Norbert Kaminski, PhD, a professor of pharmacology & toxicology and director of the Center for Research on Ingredient Safety at Michigan State University told Health.

Even if you’re not familiar with titanium dioxide in makeup, it’s quite likely you’ve seen it in sunscreens, specifically physical formulas. Titanium dioxide is beloved in cosmetics not only for the pigment and coloration it can provide but also for the way it reacts to light.

When E171 is part of a food product, it passes through the digestive system without causing harm because E171 combines with the other ingredients. 

1. Sheet iron method

China’s TiO2 exports were booming in 2016. The continuously depreciating RMB and the increasing export scales of China’s manufacturers have strengthened this development throughout the year. As a fact, many of China’s producers exported their products with a lower price while achieving higher profit margins in the domestic market of TiO2. Tranalysis, a trade analysis provider, now reveals the top 10 Chinese TiO2 exporters of the year 2016 with the original data of China Customs.

Bluescope Steel now specifically mention sunscreen & titanium dioxide use in their warranty so they no longer have to pay out for the damage caused by a little bit of transferred sunscreen residue.

As mentioned above, these oxide NPs are harmful in part because both anatase and rutile forms are semiconductors and produce ROS. Particularly, P25 kind has band-gap energies estimated of 3.2 and 3.0 eV, equivalent to radiation wavelengths of approximately 388 and 414 nm, respectively. Irradiation at these wavelengths or below produces a separation of charge, resulting in a hole in the valence band and a free electron in the conduction band, due to the electron movement from the valence to conduction bands. These hole–electron pairs generate ROS when they interact with H₂O or O₂ [43,44]. It was described that they can cause an increase in ROS levels after exposure to UV-visible light [45]. The NBT assay in the studied samples showed that bare P25TiO₂NPs produce a large amount of ROS, which is drastically reduced by functionalization with vitamin B2 (Fig. 5). This vitamin, also known as riboflavin, was discovered in 1872 as a yellow fluorescent pigment, [46] but its function as an essential vitamin for humans was established more than sixty years later, and its antioxidant capacity was not studied until the end of the XX century [47,48]. This antioxidant role in cells is partially explained because the glutathione reductase enzyme (GR) requires it for good functionality. This enzyme is the one in charge of the conversion of oxidized glutathione to its reduced form which acts as a powerful inner antioxidant and can quench the ROS [49,50]. The cost of this action is that the glutathione is converted to the oxidized form and needs to be recovered by the GR. Consequently, the cells need more vitamin B2. Another glutathione action is the protection against hydroperoxide. This activity is also mediated by riboflavin. Therefore, local delivery of this vitamin seems to significantly help the cells in their fight to keep the oxidative balance, once they are exposed to high levels of ROS.

Titanium dioxide (E 171) is authorised as a food additive in the EU according to Annex II of Regulation (EC) No 1333/2008.  

It is suitable as an alternative to titanium dioxide when higher acid resistance is required, such as in adhesive joints and sealants. 

④ Ink industry: titanium dioxide is also an indispensable white pigment in advanced ink. The ink containing titanium dioxide is durable and does not change color, has good surface wettability and is easy to disperse. The titanium dioxide used in the ink industry includes rutile and anatase.