The conventional surface treatment methods of titanium alloy include glow discharge plasma deposition, oxygen ion implantation, hydrogen peroxide treatment, thermal oxidation, sol-gel method, anodic oxidation, microarc oxidation, laser alloying, and pulsed laser deposition. These methods have different characteristics and are applied in different fields. Glow discharge plasma deposition can get a clean surface, and the thickness of the oxide film obtained is 2 nm to 150 nm [2–8]. The oxide film obtained from oxygen ion implantation is thicker, about several microns [9–14]. Hydrogen peroxide treatment of titanium alloy surface is a process of chemical dissolution and oxidation [15, 16]. The dense part of the oxide film is less than 5 nm [17–21]. The oxide film generated from the thermal oxidation method has a porous structure, and its thickness is commonly about 10-20 μm [22–25]. The oxide film from the sol-gel method is rich in Ti-OH, a composition that could induce apatite nucleation and improve the combining of implants and bone. It has a thickness of less than 10 μm [26–28]. Applied with the anodic oxidation method, the surface can generate a porous oxide film of 10 μm to 20 μm thickness [29–31]. Similarly, the oxide film generated from the microarc oxidation method is also porous and has a thickness of 10 μm to 20 μm [32, 33].
Like all our products and ingredients, the titanium dioxide we use meets the highest standards for quality and safety, respecting all applicable laws and regulations as well as meeting our own safety assessments. Our scientists continue to review the latest scientific data and is confident that the titanium dioxide used in our products is safe.
Inhaling high concentrations of titanium dioxide dust or fumes, which may occur in occupational settings — such as in the production or processing of products containing the mineral — may cause respiratory problems like coughing, wheezing and shortness of breath, in addition to eye and skin irritation.
EFSA’s scientific advice will be used by risk managers (the European Commission, Member States) to inform any decisions they take on possible regulatory actions.