Beijing smog by Kentaro Iemoto
Wikimedia Commons

Air pollution was linked to 6.5 million deaths in 2015…

In growing countries like India, China, Pakistan, Bangladesh, Madagascar and Kenya, the researchers say that up to 1 in 4 deaths can be tied to pollution.

Particulate Matter with diameter less than 2.5 microns (PM2.5) [mainly from fossil fuel burning and vehicular emissions] is the most consistent and robust predictor of mortality in studies of long-term exposure.


4C Air has developed a method to mass produce nanofibers which are suitable for filtration. Roughly one hundred times smaller in diameter than the fibers in commercially available filters, the increased surface area to volume ratio makes them excellent at PM2.5 capture and filtration.

These fibers have an ultra-low basis weight, are optically transparent, and have low resistance to air flow, making them ideal for innovative PM2.5 window screens and integration into personal face masks. We are also exploring integration into filters for HVAC and automotive exhaust.

We are also developing fibers with high temperature stability, providing a potential solution for high temperature filtration.


Nanomaterial-based filters

4C Air Window Screen

Home and commercial solution

By integrating our nanofiber with perforated or mesh based materials, we have developed a new and innovative PM2.5 filtering window screen which has:

  • Up to 99% efficiency for particles of 2.5 microns
  • High optical transparency
  • Low air resistance

  • The filter is ideal for spring and fall ventilation, as it can also be used as a pollen filter. The product is not recommended to be used during high or dangerous pollution levels (AQI>200), when windows should be closed.

    *Efficiency is determined using TSI's standard CertiTest Filter Tester Model 8130A, rated for 0.3 micron particles (90% efficiency).

    4C Air Face Mask

    Personal use

    Using our nanofiber technology, we are developing face masks for personal use. We are exploring developing our own face masks as well as integrating our material into more traditional face masks.

    More information will be available soon.

    For more information or any inquries