TiO2Mask - Identification, physicochemical characterisation and estimation of release of titanium dioxide particles from face masks applied during the COVID-19 crisis in view of risk analysis

Last updated on 28-10-2021 by Wesley Van Dessel
May 1, 2021
September 30, 2023

Financial Source


Evelien Frijns
Kristof Tirez
Lieva Van Langenhove
Johanna Louwagie
Magdalena Georgievska
Sofie Moorkens

In short

To introduce new solutions to the challenges associated with the COVID-19 pandemic, textile companies are incorporating nanofiber, nanocomposite and nanoparticle technology into face masks. For example, titanium dioxide nanoparticles are added in the production of chemical fibres as a white colorant, as a matting agent and as UV-filter. In the TiO2Mask project we aim to assess if they are safe to use in facemasks.

Project summary

The TiO2Mask project focuses on the identification, the physicochemical characterization and the estimation of release of titanium dioxide particles from commonly used face masks. Information regarding the amounts of titanium dioxide particles that are released and inhaled from face masks in normal and intensive use conditions is lacking. Titanium dioxide is classified as a carcinogen when inhaled, Carc.cat.2, H351 according to the European classification, labelling and packaging (CLP) regulation and therefore requires further research. We carry out in-situ physicochemical characterisation and an assessment of possible release of particles, which are essential to identify risks associated with wearing face masks containing titanium dioxide particles..

To determine which type(s) of face masks contain titanium dioxide, we perform an initial screening by Inductively coupled plasma — optical emission spectroscopy (ICP-OES), measuring the total amount of titanium dioxide in a selection of face masks. The measured total amount of titanium dioxide is used as a proxy for the presence of titanium dioxide particles.

The titanium dioxide particles are characterized in-situ by electron microscopy (EM). The aim is to detect, localize and measure the size, morphology, agglomeration state and elemental composition of the titanium dioxide particles in sections of the face masks. We assess the number of particles per surface area and the fraction of particles located on the edge of the fibres, most likely to be released.

Specific inhalation exposure data is essential for risk assessment. Inhalation exposure due to release of titanium dioxide particles is estimated for conditions that mimic real life conditions. This includes inhalation exposure during normal use and under specific external conditions (dry air, humid air).

We also investigate if alternative, more simple methods for evaluating the release of titanium dioxide particles can be developed. Such methods should allow assessing the fraction of particles that can be released under both normal use and extreme conditions, as well as differences in release of titanium dioxide particles between the different types of face masks.

The results of this project will provide essential information for the risk analysis of wearing face masks containing titanium dioxide (nano)particles.  


An intermediate report on the first results of the project has been published. Read the news item, the executive summary or the full report

Frequently asked questions about the TiO2Mask project

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