Quantification and Characterization of Nanomaterials Shed from Face Masks

RYM MEHRI, Timothy Sipkens, Joel Corbin, Zuzana Gajdosechova, Gregory Smallwood, National Research Council Canada

     Abstract Number: 483
     Working Group: Nanoparticles and Materials Synthesis

Abstract
During the COVID-19 pandemic, novel face masks, containing nanomaterials, have been developed and are available in the Canadian and international markets. However, little research has considered the potential health risks associated with these nanomaterials should they become dislodged (shed) from the masks and inhaled by the wearer. This makes it exceptionally challenging to drive standard development and regulation of these new materials. In this work, we develop a novel approach to quantify the nanomaterials shed by face masks, including the composition of the released nanomaterials. Particular is placed on products containing titania (TiO2).

The face masks themselves are first analyzed using inductively-coupled plasma mass spectrometry (ICP-MS) and electron microscopy with energy dispersive X-ray analysis (EM-EDX), to determine the morphology, location and composition of the particles in the samples. Next, the masks will be subject to a variable flow of air to prompt particle shedding. Flow rates will vary up to 85 L/min, roughly mimicking different breathing conditions from light to heavy physical activity. Released particles will be characterized in terms of their number concentration and particle size distribution, using a condensation particle counter and scanning mobility particle sizers, respectively. Shed particles will also be collected onto filters to determine the composition and size of the released particles using EM-EDX and single particle ICP-MS.

These combined measurements will lead to assessments of the particle mass concentration, elemental composition and particle size distribution of the shed particles, which can help in performing risk assessments on these products.