Study on the presence of titanium dioxide in face masks: initial findings

Published on: 
Thursday, October 28, 2021
Last updated on 28-10-2021 by Wesley Van Dessel

Sciensano is conducting a study on the possible health effects of (nano)particles in face masks. The first results of the TiO2Mask project show the presence of varying amounts of titanium dioxide particles in face masks. We still need to investigate whether and to what extent these particles can actually be released and pose a health risk.

Titanium dioxide is used, among other things, to whiten textile fibres, to make them matt or to protect them from UV radiation and discolouration. Tests on a sample of masks on the Belgian market show that this substance is also widely used in the production of face masks. The quantities vary greatly, ranging from a few micrograms to 0.15 grams of titanium dioxide per mask. The (nano)particles are located both on the surface and in the core of the textile fibres.

Titanium dioxide particles are classified as potentially carcinogenic to humans if inhaled. In contrast to the particles inside the fibres, the particles on the surface of the fibres may potentially be released. There is currently no reliable method to measure the release of these particles and the actual exposure to the particles released by the masks. Therefore Sciensano has mathematically approximated the release of these particles and the possible health risk to the user, based on a scenario where the face mask is worn intensively. This approach may lead to an overestimation of the possible health risks as we currently have no indication that titanium dioxide particles are released in large quantities, but some masks contain so much titanium dioxide that a potential risk cannot be ruled out.

In its scientific opinion of July 2021 on nanoparticles in mouth masks (available in Dutch and French), the Belgian Superior Health Council states that the potential health risk of using mouth masks does not outweigh the benefit of using them to prevent COVID-19 infection. The current study results do not show any acute evidence to contradict this opinion.

Sciensano has sent the report containing the first results of the study to the competent authorities in Belgium.

In the next phase, we will work on the development of a method to measure the actual exposure to the released particles with the help of our colleagues at VITO and UGent.


More information on the TiO2Mask project

Frequently asked questions

Executive summary of the report and full report

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