While a P95 can also filter out 95% of small particles, it has the additional ability to strongly protect the wearer from oil particles. ... In the same way an N95 filters out 95% of small particles, an N99, R99, or P99 filters out 99% of small particles, and an N100, R100, or P100 filters out 99.97%.
What kind of mask should I wear during the COVID-19 pandemic?
COVID-19Common questionWhat kind of mask should I wear during the COVID-19 pandemic?People must wear masks that completely cover the mouth and nose. Masks should fit snugly against the sides of the face. See CDC's guidance for attributes of masks needed to fulfill the requirements of the Order.
What types of masks are most and least effective at preventing the spread of COVID-19?
COVID-19Common questionSee full answerWhat types of masks are most and least effective at preventing the spread of COVID-19?Researchers at Duke University created a simple setup that allowed them to count the number of droplet particles released when people spoke the phrase "Stay healthy, people" five times in a row. First, the study participants spoke without a mask, and then they repeated the same words, each time wearing one of 14 different types of face masks and coverings.As expected, medical grade N95 masks performed best, meaning that the fewest number of droplets got through. They were followed by surgical masks. Several masks made of polypropylene, a cotton/propylene blend, and 2-layer cotton masks sewn in different styles also performed well.Gaiters ranked dead last. Also called neck fleeces, gaiters tend to be made of lightweight fabric and are often worn by athletes. Bandanas also ranked poorly.