Freshwater algae show low-to-moderate susceptibility to TiO2 exposure, with more pronounced toxic effects in the presence of UV irradiation. It has also been shown that nano-sized TiO2 is significantly more toxic to algae Pseudokirchneriella sub-capitata than submicron-sized TiO2. Hund-Rinke and Simon reported that UV irradiated 25 nm TiO2 NPs are more toxic to green freshwater algae Desmodesmus subspicatus than UV irradiated 50 nm particles, which is in agreement with Hartmann et al. UV irradiated TiO2 NPs also inactivated other algae species such as Anabaena, Microcystis, Melsoira and Chroococcus. It was demonstrated that smaller particles have a greater potential to penetrate the cell interior than submicron-sized particles and larger aggregates. Studies have shown that the amount of TiO2 adsorbed on algal cells can be up to 2.3 times their own weight.
Genotoxicity refers to the ability of a chemical substance to damage DNA , the genetic material of cells. As genotoxicity may lead to carcinogenic effects, it is essential to assess the potential genotoxic effect of a substance to conclude on its safety.
Fig. 7. Lipid peroxidation measured on samples of MSSA with: A) 0.2 mg/mL P25TiO2NPs; B) 0.02 mg/mL P25TiO2NPs; C) 0.2 mg/mL VitaminB2@P25TiO2NPs; D) VitaminB2@P25TiO2NPs 0.02 mg/mL after 3 h of irradiation (red) and 6 h (blue). MDA could not be detected after 6 h of irradiation in a sample with P25TiO2NPs. Error bars are too small to be seen in graphic and p < 0.05 between C-D and A-B.
In Home Care products, the presence of titanium dioxide is declared in line with local regulations, which can vary across the world. In some countries, titanium dioxide is not declared if only a small amount of the ingredient is used. In other countries titanium dioxide is grouped under ‘colourants’ in the ingredients list. In Europe, regulation requires all home care ingredients to be disclosed through a supporting website. You can find our product ingredient information page by visiting ‘