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Flo Mask Test Reports

Because your trust is so important to us, we feel it's critical to be transparent with our test reports by making it publicly available.

The following reports prove that Flo Mask performs at the highest levels, as tested by renowned laboratory institutions in the USA and abroad. And unlike other elastomeric mask companies, we make it a point to test our masks as a complete system, not just the filter.

Flo Mask Pro FFP2 Declaration of Conformity (PDF)

    Flo Mask Pro KN95 Test Report (PDF)

    NIOSH Test Report (Mask Challenge Round 4)

    NIOSH + NIST Video (Mask Challenge Round 2)

    Additional Independent Test Reports


    Frequently Asked Questions

    Q. What tests has Flo Mask performed?

    Flo Mask Pro (adult mask in both sizes), has been tested by multiple institutions around the world:

    • NIOSH independently tested our Pro Filter to achieve over 99% filtration efficiency while our Everyday Filter achieves over 95%. This testing was performed as part of our participation in the Biden Adminstration's Mask Challenge.
    • Our Pro Filter has achieved European FFP2 certification.
    • Our Pro and Everyday Filters have been tested to meet KN95 standards.

    Flo Mask Kids has been tested by an independent lab called 4C Air. The filter media on our kids' masks were specially designed for little lungs to maximize breathability while maintain high filtration efficiency. Holding our kids' filter to adult test standards made no sense. But when adjusting the flow rate at 6.3 LPM to better match normal respiratory rates of most children, Flo Mask for kids achieved over 95% filtration efficiency.

    Independent test reports for kids and adult masks can be found in the links above


    Q. I live in Europe, can I get a mask?


    Yes! It's now available for pre-orders at


    Q. Will Flo Mask fit me and my child?

    Kids' mask recommended for 4 to 12 years of age. 

    Fit was our core pillar from day one. That's why our team invested heavily in utilizing the very best 3D scanning technology to scan elementary aged kids across various ethnicities. As a result, we believe we've created an optimal fit for most kids ages 4 to 12. Our incredibly soft silicone gasket has been engineered to flex and accommodate various face shapes and sizes among this age group. 

    Under 4 years of age. 

    Although our mask wasn’t designed for kids younger than 4, we’ve had many parents use Flo Mask on kids as young as 2 and the feedback we’ve received is that it fits quite nicely. However, this is a decision a parent must make. To better help you make this decision, our mask dimensions (measuring inside dims from silicone gasket to silicone gasket) are:

    Height (nose to chin): 60mm 

    Width (sides of mouth): 64mm 


    Two nose bridge sizes for adults.

    Our adult mask was designed as a one size fits most with just a single difference, the nose bridge size, which we offer in two sizes: low/med and med/high. Based on our data, it should fit over 90% of the world's adult population.

    Use our nose bridge print out tool here (to ensure accurate scaling, please print directly from Adobe Acrobat).

    Here are our mask dimensions (measuring inside dims from silicone gasket to silicone gasket).

    Height (nose to chin): 77mm 

    Width (sides of mouth): 86mm 


    Q. How often should I change the filter?

    Based on our load testing data, we recommend the following assuming an AQI of 100 or less (average air quality index in Shanghai):

    • Kid Filter - Up to 8 hours of use
    • Pro Filter - Up to 40 hours of use
    • Everyday Filter - Up to 20 hours of use

    Replace more frequently in poor air quality environments.

    Fresh filters help maintain good breathability and when not in use, please store the mask in the included microfiber pouch as the filters are electrostatically charged and will continue to attract particulates in the air if left sitting out.


    Q. Does Flo Mask have an exhaust valve?

    Flo Mask does NOT have an exhaust valve. We found that the high breathability of our filters reduced the need for an exhaust valve.


    Q. Is the filter recyclable?

    Unfortunately, the unique material and manufacturing process to create our filters does not allow it to be recyclable. Please properly dispose of the filter in the trash and remember to always wash your hands with soap after handling a used filter.


    Q. Can I use Flo Mask or Flo Mask Pro for an MRI? 

    The primary housing of Flo Mask and Flo Mask Pro are made of polycarbonate and silicone, which do not have any metal in them. However, the straps do contain metal in the buckle and push button lock. Therefore, if you're looking to use Flo Mask or Flo Mask Pro for an MRI, please be sure to replace both straps with your own pure elastic ones. 


    Q. Does Flo Mask contain latex rubber? 

    The elastic straps that come with each mask currently use latex rubber. We now sell latex-free replacement straps and are working through our supply chain to have latex-free as a standard offering with each mask. Please understand this will take us time to work through our inventory.


    Q. Where is Flo Mask made?

    One of the most important aspects of Flo Mask, the filter, is manufactured here in the United States. The mask itself is manufactured in China through a highly reputable manufacturer that makes products for some of the most notable brands in the world. All packaging is printed in California and we perform the final assembly here in the San Francisco Bay Area to ship out to you.