Masks that help protect against COVID-19, air pollution, and smoke from fires

  • Wildfire smoke and viral illnesses like COVID-19 pose serious airborne threats to people's health. In response, CHC has produced high-filtration masks made with an advanced nanospun fabric which can filter out 95% of sub-micron particles*, offering more protection against these threats.

  • Our DIY masks were tested and found to filter out nearly 90% of submicron aerosols in a real-life, quantitative fit test (University of North Carolina). By analogy to N95s commercially available in stores, which must filter out 95% of such particles, you might call it an "N85" (not a legal definition).

Build Your Own

 Our DIY masks have not been certified by the National Institute for Occupational Safety & Health (NIOSH). You can find information about the mask filtration material on filti.com, and independent testing results of the material at maskfaq.com/test-results.

With these DIY masks and other commercial masks we source, we aim to help fill the persistent gap between what is available and affordable, and what we need to protect health for everyone in our community. For anyone in or near the Bay Area, we can also recommend connecting with Mask Bloc Sunset SF, Mask Bloc East Bay, Mask Oakland (on hiatus), Mask Bloc San José, Mask Sonoma, Mask Bloc UC Davis, and Mask Bloc 916. Find other blocs near you at maskbloc.org.