It's worth noting that this is backwards in function of the surgical masks. The surgical mask which strap on over the nose and mouth are about preventing the wearer from spreading disease by catching the exhaled droplets and crud. They help for inhaling, but lots of inhaled air gets in around the edges. It's right there in the name "surgical mask", you wear it in surgeries to avoid infecting the patient.
The positive pressure mask is about providing only safe air to the wearer, protecting them from others.
The passive respirator I wear when sanding or working with solvents is P100 (P means tolerates oil, N means doesn't and the 100 is better than the 95 you see in N95), but it is also backwards. It protects my airways, but has an exhale valve which lets my lung leavings right out into the atmosphere, and it does nothing for my eyes.
It seems literally to be designed to expel the air within the mask and replace it with external air. Which is the opposite of what most masks aim to achieve (contain droplets within the mask to prevent them from reaching others), and would seem to increase the risk to people nearby.
The positive pressure mask is about providing only safe air to the wearer, protecting them from others.
The passive respirator I wear when sanding or working with solvents is P100 (P means tolerates oil, N means doesn't and the 100 is better than the 95 you see in N95), but it is also backwards. It protects my airways, but has an exhale valve which lets my lung leavings right out into the atmosphere, and it does nothing for my eyes.