Titanium dioxide is an inert earth mineral used as a thickening, opacifying, and sunscreen ingredient in cosmetics. It protects skin from UVA and UVB radiation and is considered non-risky in terms of of skin sensitivity. Because it is gentle, titanium dioxide is a great sunscreen active for sensitive, redness-prone skin. It’s great for use around the eyes, as it is highly unlikely to cause stinging.

Titanium dioxide nanoparticles are commonly found in a wide-range of consumer goods, including cosmetics, sunscreens, paints and colorings, ceramics, glass, textiles, construction materials, medicine, food, food packaging, and more. In Europe, cosmetic companies are required to label products that contain nanoparticles. In the U.S., companies are not.

Another important application of titanium dioxide is in the production of sunscreen and other skincare products. Titanium dioxide is a key ingredient in many sunscreens due to its ability to reflect and scatter ultraviolet (UV) radiation, providing protection against harmful UV rays. Manufacturers of titanium dioxide for sunscreen products often use special coatings and surface treatments to enhance its UV-blocking properties.

The lack of clear regulations and controls explains that P25TiO₂NPs are still found in many of the commercialized sunscreens in the market. Some of them are coated to reduce the photoactivity of the anatase form, which is known to be responsible for tissue damage, but not enough studies were made on these coated forms. The anatase photoactivity could trigger the production of reactive oxygen species (ROS) generation, as it was stated before. The ROS are chemically reactive species containing oxygen, such as peroxides, superoxide, hydroxyl radical, and singlet oxygen. They are regularly produced in the biological milieu and counterbalanced by physiological antioxidant defense mechanisms. However, an abrupt increase of ROS may result in non-reversible damage to the skin cells. The effects of coated and uncoated P25TiO₂NPs need therefore to be studied, and articles on this topic present different conclusions. [11], [12], [13] Recent literature on this topic found that TiO₂NPs inhalation provokes serious genotoxicity and DNA damage [14], [15], [16], [17]. On the other hand, some studies in rats have reported no significant harm to genetic material [18], [19], [20], [21], [22].

Titanium dioxide is produced in two main forms. The primary form, comprising over 98 percent of total production, is pigment grade titanium dioxide. The pigmentary form makes use of titanium dioxide’s excellent light-scattering properties in applications that require white opacity and brightness.

≥ 5 % of standard sample

Most notably, a European Food Safety Authority safety assessment published in May 2021 pointed to genotoxicity concerns, as suggested by previous research. Genotoxicity is the ability of chemicals to damage genetic information such as DNA, which may lead to cancer.