MakerMask collaborated with the Energy and Aerosols Laboratory at the University of British Columbia (UBC) to explore filtration and breathability of nonwoven and woven fabrics for reusable masks before and after washing. This post summarizes the key findings. See the paper for details: https://doi.org/10.4209/aaqr.220044 Motivation Although mask mandates have been rescinded, washable masks remain widely […]
The Spectrum of Masks: Exploring Mask Options
Two years into the COVID-19 pandemic, a wide variety of mask options are available. How do they compare? Figure 1 shows masks arranged into a spectrum, roughly in order of their filtration efficiency. Different masks serve different tasks. A mask can function as source control (my mask protects you) and/or personal protective equipment (PPE) (my […]
Masking Children for School
The highly infectious Delta variant of COVID-19 is on the rise just as the school year begins. Vaccination is one of the most powerful tools to protect students and broader school communities. However, there is currently no authorized COVID-19 vaccine for children under 12. We must rely on other mitigation measures to protect them. In July 2021, the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) both updated their guidance to recommend universal indoor masking for everyone in school, regardless of vaccination status, along with other mitigation measures. What masks should parents select to protect their children as they return to school?
Fabric Mask Material Testing Results! ASTM 2100 and F3502
A huge thank you to everyone that has contributed to our fabric mask material testing campaign! The results from the testing campaign are finally in. We tested two different 3-layer fabric combinations to establish baseline performance for fluid resistance, breathability, bacterial filtration efficiency (~3um particles), and submicron particle efficiency (~0.3um). These tests focused on two […]
Masks for COVID: Literature Highlights
In this post we share some of our favorite articles about mask science. Since the beginning of this pandemic over 6000 papers have been published on masks. For scientists and sewists alike, sorting through all this information can be daunting! We have gathered our top recommendations for those looking to join us in immersing themselves […]
Washing Fabric Masks: Knowns and Unknowns
Recently, we’ve been hearing a lot of questions about washing and reusing fabric masks. There are a wide range of “best practices” emerging from government organizations, sewist groups, and journalists. This post discusses cleaning of masks containing spunbond non-woven polypropylene (NWPP) layers, and clarifies some distinctions between washing and disinfection. Introduction First, a caveat — […]
Mask Material Testing Plan
Update (February 12, 2021): Thanks to our generous community and a grant from Helpful Engineering, we exceeded our fundraising goal for mask testing! In addition to the originally planned fluid resistance, breathability, and bacterial filtration testing of our fabric combinations, we were able to add mask-level NaCl aerosol filtration tests to our campaign. Thank you […]
WHO Fabric Mask Guidance – December Updates
On December 1, 2020, the World Health Organization (WHO) updated their guidance on fabric masks, “Mask Use in the Context of COVID-19 (December, 2020)”, including their “Updated Guidance on Non-Medical (Fabric) Masks” (p. 19-22). This post pulls out key quotes from the new WHO guidance, touching on their recommendations for layering, mask performance standards, and […]
Finding and Selecting Polypropylene for Washable Masks
In this post we discuss how we think about selecting spunbond nonwoven polypropylene (NWPP) fabrics for washable masks, where we have found spunbond NWPP, and why we’ve chosen Smart-Fab® Double-Thick for our next round of testing. Our Mission Our mission is to share information with the public about the best emerging mask science to help […]
Adopting WHO Guidance on Fabric Masks for COVID-19
This paper describes key differences between the WHO and the CDC fabric mask guidelines, including the rationale for the inclusion of hydrophobic polypropylene materials in the WHO guidance, and was initially shared on the SSRN Preprint Server on June 26, 2020. [Update: December 2020)] The WHO updated their guidance on Fabric Masks December 1, 2020. […]
