# Riboflavin based setup as an alternative method for a preliminary screening of face mask filtration efficiency

## TL;DR

This study introduces a new, eco-friendly method using riboflavin to test face mask filtration efficiency as an alternative to traditional bacterial testing.

## Contribution

A novel, low-cost, and rapid riboflavin-based setup for preliminary mask filtration screening is proposed.

## Key findings

- The riboflavin-based setup showed filtration efficiency values about 2% higher than bacterial filtration efficiency.
- The method correlates well with traditional bacterial testing and can be used in chemical-physical labs.
- The setup is eco-friendly, rapid, and does not require biosafety labs or specialized staff.

## Abstract

Face masks are essential in reducing the transmission of respiratory infections and bacterial filtration efficiency, a key parameter of mask performances, requires the use of Staphylococcus aureus and specialised staff. This study aims to develop a novel method for a preliminary screening of masks or materials filtration efficiency by a green, easy and rapid setup based on the use of a riboflavin solution, a safe autofluorescent biomolecule. The proposed setup is composed of a commercial aerosol generator commonly used for aerosol therapy, custom 3D printed aerosol chamber and sample holder, a filter for downstream riboflavin detection and a vacuum pump. The filtration efficiency of four different masks was assessed using the riboflavin-based setup and the bacterial filtration efficiency (BFE). The averaged filtration efficiency values, measured with both methods, were similar but were higher for the riboflavin-based setup (about 2% for all tested samples) than bacterial filtration efficiency. Considering the good correlation, the riboflavin-based setup can be considered validated as an alternative method to bacterial filtration efficiency for masks and related materials fabrics filtration efficiency screening but not to replace regulation approaches. The proposed setup can be easily implemented at low price, is more rapid and eco-friendly and can be performed in chemical-physical laboratories without the needing of biosafety laboratory and specialised operators.