Met One Instruments HH Particle Counter vs. Paper Towels!
Are Paper Towel Masks Effective at Blocking Viruses? 2020-03-08 Paddy Robertson Coronavirus Masks Paper towel test at capturing virus-sized particles In a recent study, researchers tested household materials that could be used to make DIY masks, but they left out one common material—paper towel masks (also called “kitchen paper”). Could paper towel be an effective material for making homemade masks in times of crisis and shortages? Smart Air Engineer Paddy tested its effectiveness in the Beijing lab. DIY mask test of paper towel effectiveness Putting Paper Towel Masks to The Test
Paddy used a Met One GT-521S particle counter to test how well a single and double layer of paper towel filtered out particles down to 0.3 microns. Paddy ran the Met One for one minute, measuring the total number of particles passing through the kitchen paper versus the same setup with no filter. Paper towel test at capturing virus-sized particles How Big Are Viruses?
Just how small is 0.3 microns compared to viruses? On average, coronavirus particles measure approximately 0.1 microns in diameter, so 3 times smaller than measured in our test. However, 0.3 microns is an important size to test, because 0.3 micron particles are the most difficult to capture. Particle Sizes – Virus Labelled The crazy reality is that particles smaller than 0.3 microns are actually easier to capture. Don’t believe us; believe the data. Here’s the science behind it » Paper Towel Particle Capture The results weren’t great. A single layer of kitchen paper captured just 23% particles. Adding an extra layer only increased particle capture to 33%. Paper Towel Mask Particle Capture Effectiveness Microns For larger 2.5 micron particles, paper towel performed better. The single layer of kitchen paper captured 52% of these larger particles. Update: new data on paper towel masks – we’ve published new data on the effectiveness of paper towels in our Ultimate Guide to DIY masks article. This uses a new and improved testing method, which shows paper towels are more effective than originally thought! Learn more: The Ultimate Guide to DIY Face Mask Materials → Do Paper Towel Masks Fit Tight? One thing this test doesn’t cover is fit effectiveness–how leaky a DIY mask would be. Not surprisingly, masks that fit better will let fewer particles in. That’s one of the reasons why surgical masks score lower on fit tests than N95 masks. UMass Surgical Mask Study Virus EN Yet Studies Find Mask Leakage Has Small Effect on Flu Virus Transmission Although surgical masks (and presumably DIY masks) are more leaky than N95 masks, randomized studies that have tracked infection rates have found that surgical masks are just as effective as N95 masks at preventing the transmission of viruses.