Can Japanese Pitta Masks Protect Against Coronavirus?

pitta masks protect us from coronavirus

With the outbreak of the 2019 novel coronavirus, interest has surged in Japanese Pitta masks. Smart Air has received a flood of questions about how well they filter the coronavirus and other viruses.

Japanese Pitta mask popular in Chinese cities as well as India and Korea


The Japanese Pitta masks are sleek and incredibly popular, but there’s little information available on how well they filter out tiny virus-sized particles.

How Big Are Coronavirus Particles?

Scientists have taken electron microscope images to measure the size of the coronavirus SARS-CoV-2. They found that the “virions” (or particles) are approximately 125 nm (0.125 microns) in diameter. The smallest particles are 0.06 microns, and the largest are 0.14 microns.

Coronavirus virus particle size

That makes the coronavirus particles smaller than PM2.5 particles, but bigger than some dust particles and gases. However, sometimes the coronavirus hitches a ride on water droplets, which will make the size bigger.

Coronavirus particle size compared to other pollution types

How Well Can Japanese Pitta Masks Capture Virus-sized Particles

Coronavirus & Mask Livestream

Wondering whether masks work to protect you against the coronavirus? Check out our livestream recap covering all the info here!

To test how well the Pitta masks can capture tiny particles, Smart Air engineer Kang Wei purchased a pack of Pitta masks and tested them against 3M N95 masks.


To measure particles, we used a Met One 531, which measures particles as small as 0.3 microns. That’s about 3 times bigger than the coronavirus. Research shows that 0.3-micron particles are the hardest to capture. So if a mask does a good job at capturing particles 0.3 microns in diameter, then we can be confident it can also capture smaller, 0.1 micron particles.

Not sure why? Check out the science behind the magic ‘0.3 micron’ particle size »

Pitta Mask Effectiveness

We compared the Japanese Pitta mask with two 3M N95 masks. The results weren’t pretty.


comparison graph and data of effectiveness of Pitta mask and 3M mask at filtering PM0.3 and PM2.5


The Pitta mask captured an astounding 0% of 0.3-micron particles and only 64% of larger 2.5-micron particles. Maybe the result is a fluke? Separate tests from AQ Blue found similar results.

Pitta Mask PM2.5 Test

This result strongly suggests that the Pitta mask does a very poor job of capturing 0.1 micron particles, like the coronavirus particles. Meanwhile, the 3M masks captured over 90% of 0.3 micron particles.

In fact, data shows even a surgical mask would provide more protection from the coronavirus than the Pitta mask. Tests from researchers at the University of Massachussetts found that a surgical mask they bought on the streets of Nepal captured over 60% of 0.1 micron particles. A 3M N95 mask captured over 80%.



In short, this data shows the Pitta mask is not effective at capturing small particles. That means it won’t do a good job filtering things like PM2.5, viruses, bacteria, or fine particles.


Does Pitta Claim It Filters Viruses?

In defense of Pitta, their official store never claims that it is effective against PM2.5 or smaller particles for that matter.

Pitta mask official store claim PM10


The Pitta masks claim to be 99% effective at filtering out pollen and dust particles, which range from 5-100 microns in sizeThe Pitta mask might be great at capturing pollen, but for viruses such as the coronavirus and flu, the Pitta mask doesn’t cut it.

Bottom Line: How Well Pitta Masks Can Capture COVID-19 Virus

Pitta masks can capture large pollen particles and are stylish to boot! However, they are completely ineffective against 0.3-micron particles.

This means they do a very poor job of capturing the coronavirus or any other virus for that matter. A far more effective and affordable solution to filter out viruses such as the coronavirus would be to use any of one of the high-scoring, scientifically validated masks.

Read more on the method we used to test how well Pitta masks capture tiny, coronavirus-sized particles »

Covid19 coronavirus best masks materials fundraiser

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Are the Pitta masks washable & reusable?
And are they at least as effective as the homemade cotton masks?


Depressing… Cool, likely rewashable masks… Completely useless. I guess a leather mask with no pores at all, assuming I won’t suffocate?


Can cloth or N95 masks be sterilized with a steam iron?

Liz - Smart Air

Hi Michael, Liz here. We haven’t tested steam iron yet. We know there’s a huge demand for reliable, science-backed data right now, so we’ve created a campaign to gather information on what our readers wants to test. To vote on what test you expect to see and support our campaign, visit our page here:

Stephanie P.

I had a Nurse from 1 of the big Philadelphia hospitals tell me to remove my mask place in a paper lunch bag and leave in the hot car for a few days ad it could be worn again… is that true Paddy/Michael????

Liz - Smart Air

Hi, Stephanie, we only know that simply leaving mask out for dry will disinfect it. Here is our original article:
Did you friend tell you why wrap it up in a lunch bag? Personally I would feel that slows the mask to dry and because it’s damp in the bag, it’s easier to generate more bacteria.


How would the Pitta compare to cloth masks? Especially with the trend of people making their own cloth masks now.

Harrison Anderson

Can a mask be microwaved to quick sanitize it?

Ethel - Smart Air

We’ve just published an article on microwaving masks, feel free to check it out!