Food safety experts in the European Union (EU) have recently updated their safety assessment of TiO2 as a food additive. In Europe, TiO2 is referred to as E171, in accordance with European labelling requirements for food additives. The EU expert panel took into account toxicity studies of TiO2 nanoparticles, which to this point had not been considered relevant to the safety assessment of TiO2 as a food additive.
In summary, the Food Directorate's position is that there is no conclusive scientific evidence that the food additive TiO2 is a concern for human health. This is based on a review of the available scientific data relevant to food uses of TiO2. However, we will continue to monitor the emerging science on the safety of TiO2 as a food additive and may revisit our position if new scientific information becomes available.
Unfortunately, we studied that all of the above methods are employed after machining or forming, and they require a long process chain and costly production types of equipment [21–24]. Therefore, we proposed a titanium alloy implant preparation process that integrated with cutting and surface modification. The oxygen-rich atmosphere increases the partial pressure of oxygen in the oxidizing environment, and the heat generated during the cutting process increases the temperature and the rate of the oxidation. It uses the cutting heat and oxygen-rich atmosphere generated during the cutting process to form the oxide film (TiO2) to improve the corrosion resistance of the titanium alloy. The experimental equipment is shown in Figure 2. Since the cutting temperature is the most important factor in the oxide film formation process, this paper carried out researches based on theoretical analysis and experimental investigation to acquire an ideal temperature range for the cutting process to achieve the oxide layer.