FAQ

We offer 3 different mask sizes for ages 3+ (Kids, Medium, Large).  Use the graphic below to determine the proper size you need: 

 4C air started with our headquarters of operation located in Sunnyvale, CA and our patented nanomaterial was developed at Stanford University.  We have partnered with a very trusted mask manufacturer located in China who completes final production.  We regularly test our mask shipments for quality and efficiency to ensure the quality of our products.

Our masks are designed to be disposed after use and due to liability concerns, we cannot advise reusing them.  There are however, several EUA methods the CDC provides which have been used on our masks with reported success from our customers. These can be reviewed here: https://www.cdc.gov/niosh/npptl/cleaning.html

Our masks are comprised of 5 very thin layers.  Thanks to our innovative nanomaterial, our masks provide N95 level or higher filtration efficiency while offering exceptional breathability and thinness. 

There is no risk of breathing in fibers from our mask. The nanomaterial is bonded with two outer layers and is produced in a similar way to other masks which have been tested for safety.  Several studies have been performed verifying the general safety of masks which you can reference below:

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7773316/
• https://pubs.acs.org/doi/10.1021/acsanm.0c01562

 Additionally, in a study conducted by the US National Library of Medicine National Institute of Health, nanofiber material was shown to be completely safe for use in masks

Our masks provide filtration efficiency up to 99% and above while being more breathable than similar level masks such as N95.  Our masks are nearly paper thin and use less overall material than traditional masks.

If worn properly our masks do not fog up glasses thanks to allowing more air pass through the filtration membrane.