Ability of Fabric Facemasks Materials to Filter Ultrafine Particles at Coughing Velocity

Objectives

We examined the ability of fabrics which might be used to create homemade face masks to filter out ultrafine (0.1μm and smaller in diameter) particles at the velocity of adult human coughing.

Method

Twenty commonly available fabrics and materials were evaluated for their ability to reduce air concentrations of ultrafine particles at a face velocity of 16.5 m/s. Further assessment was made on the filtration ability of select fabrics while damp and of fabric combinations which might be used to construct homemade masks.

Results

Single fabric layers blocked a range of ultrafine particles. When fabrics were layered, significantly more ultrafine particles were filtered. Nonwoven fusible interfacing significantly increased filtration.

Conclusions

The current coronavirus pandemic has left many communities without access N95 facemasks. Our findings suggest that face masks made from layered common fabric can help filter ultrafine particles and provide some protection for the wearer when commercial facemasks are unavailable.

STRENGHTS AND LIMITATIONS OF THIS STUDY

• Tested a large number of potential facemask materials, including materials currently in common use such as Lycra which have not been previously tested

• Evaluated filtration efficiency at coughing velocities, more closely mimicking use-case of masks worn for community protection than previous studies

• Assess the data from prior published work and current study, creating a picture of Filtration Efficiency and the impact of velocity

• Did not discriminate between pathogenic and non-pathogenic particles

• Breathing resistance was estimated based on qualitative feedback