Puraka Masks manufactures pm2.5 filters to China’s GBT2626 standard for particulate reduction, with some additional elements of the more recent GBT32610-2016 standards (see attached). When we formed the company after the West Coast wildfires of 2016 and 2017, we found that these specifications for re-usable “pollution masks”, used since at least 2006 in much of Asia, achieved a healthy balance of filtration and comfort. This was especially relevant to our target customers: members of certain “sensitive groups” who found themself at greater risk from wildfire smoke but who also were potentially more susceptible to harm from prolonged respirator use. For them, the pm 2.5 carbon filter was the ideal solution.adhesive mask filter
Per our laboratory results, and backed up by our own testing, the combination of fabric mask with a pm 2.5 filter yields approximately 90% filtration in the sub-micron range that’s relevant to coronavirus protection, with an air flow resistance of approximately 6-7 mm H20, consistent with the Chinese standard. Since our pivot to face barriers earlier this year, we’ve added some additional protective elements to our pm 2.5 mask, most notably a layer of high-quality apertured polypropylene and silicone spacers.