In this guest blog post Ania Mitros, Ph.D. discusses the laboratory testing data and science behind her preferred fabric combination for masks: two layers of ~65 gsm (gram/m²) spunbond nonwoven polypropylene (NWPP) plus one layer of ~130 gsm woven cotton. Her recommendation comes after reading dozens of scientific publications on the subject and investing thousands […]
In the spring of 2021 the CDC published advice on double-masking which was based on the results of a study published in February of this year. Although some people that have been fully vaccinated are wearing masks less frequently (per the CDC guidance published in May), there are many instances where mask use is still […]
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 […]
Since February of 2020, we’ve been asking for standards for masks/face coverings used by our communities. Finally, the American Society for Testing and Materials (ASTM) has established a national standard for “Barrier Face Coverings” (ASTM F3502) that are neither medical masks according to ASTM F2100 standards nor respirators according to NIOSH standards. This new standard […]
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 […]
Key result: Quantitative testing shows that fabric masks constructed from spunbond nonwoven polypropylene (NWPP) and/or quilting cotton are breathable and can satisfy NIOSH criteria for breathability. Ready for more testing? Visit our MakerMask Lab Testing Campaign for details. Introduction: Breathable Masks Breathing isn’t optional, and as COVID continues and mask wearing becomes commonplace, we are […]
This post is the first in a series of “Research Highlights” where we discuss select data and research from the literature in the context of community mask making efforts. In this post, we take a look at the filtration and breathability data for nonwoven polypropylene (NWPP) mask materials presented in: Long KD, Woodburn EV, Berg […]
In this guest post, our collaborators from the ROSE Project (Reusable Open Source Equipment) debunk some common myths about face masks for COVID-19 and share the facts about masks.