When mechanical engineer Aaron Collins uploaded his first mask test video to YouTube in August 2020, it was a break from the previous 150 videos of him riding his bicycle.
In the new video, Collins stands in his bathroom, filming with his cell phone and trying on different masks to test for fit and filtration. It was only meant to be seen by a few friends and fellow scientists, but its reach soon became wider. The video started receiving comments from people Collins didn’t know and eventually reached 20,000 views.
Since then, his YouTube channel has garnered more than a million views. Collins said he’s filling a need for people who are looking for information on how to find the most protective masks.
“I think a lot of people recognize that it was nice to be able to have someone who was evaluating masks and then publishing the data,” Collins said.
At the beginning of the COVID-19 pandemic, the usefulness of masks was a topic of debate, but Collins knew they would be an important tool. The Minnesota-based mechanical engineer had studied aerosols as an undergraduate and graduate student, which included lessons on the 2002-2004 SARS outbreak. Like COVID-19, SARS was spread by respiratory aerosols and masks were used to help contain the spread.
“It was, in the aerosol world, kind of common knowledge that if this happened again, one thing you would consider for a SARS virus would be really good respirators, protective masks and air handling and air cleaning equipment,” Collins said.
Not all masks are created equal, however, and they come in many forms with little guidance on how protective they are. Collins had hoped universities or government agencies, like the Centers for Disease Control and Prevention, would start promoting research on mask efficacy, but neither were publishing work in that area.
“I kind of was baffled by the fact that there was very little science-based discussion on that topic,” Collins said.
When highly-effective N95 masks were hard to come by in 2020, Collins started using the South Korean equivalent, KF94s. He told his wife that he wished he knew whether the masks were living up to their claim of filtering out at least 94% of particles.
“So I told her that and she’s kind of looking at me like why don’t you just test it?” Collins said. “And so then I said, ‘Yeah, why not?’”
Collins used his background in aerosol research and some scientific equipment he had in his basement to set up a lab in his bathroom. Each test begins by using an aerosol generator that uses salt and water to fill the room with particles. Then he puts on the mask he’s evaluating and uses a condensation particle counter to compare the number of particles inside the mask with the number of particles outside it. From there, Collins calculates how effective the mask is at filtering out particles.
Collins shares these tests on his YouTube channel along with more in depth mask reviews that take into account not only filtration, but fit and comfort as well. He also publishes all of his data in a public Google Doc. As of Nov. 18, he had completed 325 mask tests.
“So everything is transparent.” Collins said. “I have no financial incentive in any of this is all my own money in time.”
Collins’s research has shown that many of those KF94s were extremely effective. So are N95s and KN95s, but consumers need to be careful with counterfeit KN95s that are not as protective. He’s also found that the efficacy of surgical masks can be greatly improved by wearing a brace that holds it tight to the face and prevents air gaps.
Collins hopes the investment he’s making in his videos helps inform his viewers on the best way to protect themselves from COVID-19. If there’s one takeaway he wants people to get from his work, it’s that we have what we need to slow the spread of COVID-19, whether that’s through portable HEPA units, MERV-13 filtration systems, or masks
“All of the technology to combat [COVID-19] is readily available and inexpensive,” Collins said. “So whether that’s N95 masks or KF94s, or KN95s, … they’re all highly effective at protecting not only others, but also yourself.”