The toxicity of P25TiO₂NPs under UV radiation could be even higher when combined with other usual components of sunscreens Indeed, Soler de la Vega et al. advise that combination with parabens increases the toxicity of the final cosmetic mixture [53].

CAS: 1345-05-7

Above 20%, it is recommended to replace 1 kg TiO2 with 1.3 kg of lithopone supplier 30%.  

In their role as risk managers, the European Commission and Member States will now reflect on EFSA’s scientific advice and decide upon any appropriate regulatory measures or advice for consumers.

This constant high rate of ROS production leads rapidly to extreme macromolecular oxidation, here it is observed in the AOPP and MDA detected after 3 h in samples treated with bare P25TiO₂NPs (Fig. 6, Fig. 7). Macromolecular oxidation includes, among others, both protein and lipid oxidation. The ROS causes protein oxidation by direct reaction or indirect reactions with secondary by-products of oxidative stress. Protein fragmentation or cross-linkages could be produced after the oxidation of amino acid side chains and protein backbones. These and later dityrosine-containing protein products formed during excessive production of oxidants are known as advanced oxidation protein products (AOPP). They absorb at 340 nm and are used to estimate the damage to structural cell amino acids. Lipid oxidation is detected by the conjugation of oxidized polyunsaturated lipids with thiobarbituric acid, forming a molecule that absorbs light at 532 nm. Polyunsaturated lipids are oxidized as a result of a free-radical-mediated chain of reactions. The most exposed targets are usually membrane lipids. The macromolecular damage could represent a deadly danger if it is too extensive, and this might be the case. Moreover, it could be observed that cellular damage continues further and becomes irrevocable after 6 h and MDA could not be detected. This may be due to the fact that the lipids were completely degraded and cells were no longer viable. Lipids from the cell membrane are the most prone to oxidation. In fact, lipid peroxidation biomarkers are used to screen the oxidative body balance [51]. At the same time, AOPP values are up to 30 times higher for bare nanoparticles in comparison to the functionalized ones.

Moreover, the gravimetric method's inherent accuracy makes it a preferred choice for regulatory compliance. Many manufacturing processes are subject to stringent quality regulations, and having reliable methods for determining material composition is fundamental to meeting these standards. Accurate gravimetric analysis assists manufacturers in minimizing waste, optimizing formulations, and ensuring that end products are both effective and safe.

The disadvantage of Titanium Dioxide is that it's not cosmetically elegant, meaning it's a white, unspreadable mess. Sunscreens containing Titanium Dioxide are often hard to spread on the skin and they leave a disturbing whitish tint. The cosmetic industry is, of course, really trying to solve this problem and the best solution so far is using nanoparticles. The itsy-bitsy Nano-sized particles improve both spreadability and reduce the whitish tint a lot, but unfortunately, it also introduces new health concerns.