Reusability of face masks: Influence of washing and comparison of performance between medical face masks and community face masks

ABSTRACT

Reusability of masks is a rising environmental concern. Community face masks present a more eco-friendly option as they can be washed and reused several times. The potential reuse of single use medical face masks is also of interest. In this work, the impact of 20 wash cycles (at 60 degrees C with detergent and air-drying) on the particle filtration efficiency (particle size range 0.1-6. 5 mu m) and breathability of masks was studied. With regards to the performance of new masks, the medical mask had breathability of 31 Pa.cm(-2) whilst it ranged from 9 to 59 Pa.cm(-2) for the community face masks. Additionally, for 3 mu m particles, the filtration efficiency was 99% for the medical mask and ranged from 28%-89% for the community face masks. Mixed fabric masks were able to maintain their performance up to 20 washing cycles. The washed 100% cotton masks were less breathable but with higher filtration efficiency because of shrinkage of the fabric. The washed medical face mask was able to maintain its breathability and filtration efficiency for sizes >= 3 mu m, however the filtration efficiency was significantly reduced for the submicron particles. This was because the presence of detergent caused the loss of electrostatic charges and led to a decrease of the particle collection by the electrostatic forces. All things considered, both the medical face mask and community face masks can be reused several times, with performances in terms of breathability and filtration efficiency (for particle sizes >= 3 mu m) that remain globally little changed after washing. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http//creativecommons.org/licenses/by-nc-nd/4.0/).