IDENTIFICATION, PHYSICOCHEMICAL CHARACTERISATION AND PRELIMINARY RISK ANALYSIS OF TITANIUM DIOXIDE PARTICLES IN FACE MASKS Intermediate report TiO2-Mask COVID-19 project September 2021

In situ analysis of titanium dioxide (TiO2) particles in face masks demonstrated the presence of agglomerated TiO2 (nano)particles in all examined face masks that contain polyester or polyamide (nylon) fibres, or that are made of non-woven, synthetic fabrics. These particles resemble fibre-grade TiO2 particles. Because there are no methods available for measuring exposure directly, the methodology that ANSES applied to determine the professional exposure limits to titanium dioxide in its nanoform, was applied for a scenario with intensive use of face masks. Our calculations show that a health risk cannot be excluded for most of the examined face masks when intensively used. The applied approach may overestimate the health risks because of the conservative inhalation exposure assumptions. However, for some face masks the amount of titanium dioxide is so high that a health risk cannot be excluded even when only a small fraction of the titanium dioxide particles are released and inhaled. Currently, we have no indications that TiO2 particles are released in amounts which might result in public health risks, but so far, research and publications of TiO2 particles in textiles, and particularly of their release, are limited. In view of EFSA's conclusion that TiO2 cannot be considered any longer as safe to be used as a food additive because a concern for genotoxicity cannot be ruled out, it is advisable to issue precautionary standards to limit the presence of TiO2 particles in face masks.