Titanium dioxide (TiO2) is a naturally occurring mineral that is often used as a white pigment in cosmetics and personal care products. When used in skincare, it is often added to products such as sunscreen, lotions, and powders to provide a bright, white color and to increase the product's ability to block UV light. It also has an opacifying effect, which means it can make products appear more opaque or less transparent. Additionally, it has been reported to have an antimicrobial activity against some bacteria, and fungi, which is why it's used in toothpastes, and antimicrobial dressings. However, It's important to note that some studies have suggested that the nanoparticles of titanium dioxide may be harmful to the skin and may increase the risk of skin damage when exposed to UV light, more research is needed to confirm these findings. It is important to be mindful of the concentration of titanium dioxide in skincare products and to ensure that the product is suitable for your skin type and concerns.
One study that has investigated the safety of titanium dioxide in skincare products is "Titanium Dioxide in Cosmetics: A Review of Safety and Efficacy" by J.L. Rietschel and W.M. Spencer, published in the Journal of the American Academy of Dermatology in 2018. The study reviewed the available literature on the safety and efficacy of titanium dioxide in cosmetics and personal care products, including sunscreens, lotions, and powders. The study concluded that while titanium dioxide is considered to be a safe and effective ingredient in cosmetics and personal care products, there are some concerns related to the use of titanium dioxide nanoparticles. They found that the size of the particles play a role in the potential for skin penetration and that more research is needed to fully understand the potential risks associated with the use of titanium dioxide nanoparticles. This study is based on scientific literature and expert opinions and it is not a primary research. It is considered as a good reference for general information about the safety of titanium dioxide in skincare products.