>> Welcome back everyone to Inside Infection Control, our video series here at CDC's Project Firstline. I am Abby Carlson. I'm an infectious diseases doctor at the CDC, and it's great to have you here today. In an earlier episode, we talked about respirators, what it is and what it does. Now let's talk about a specific type of respirator that's recommended for COVID-19 and that we use a lot in healthcare, the N95. Let's start with this question. What does N95 actually mean? N95 is a term that's given to certain respirators tested and approved by our colleagues over at the National Institute for Occupational Safety and Health, or NIOSH. NIOSH is the part of the CDC that does this important work of studying worker safety and health and giving employers and workers the tools that they need to create safe and healthy workplaces. Some N95s for healthcare might also be regulated by the FDA, the Food and Drug Administration. There are two big things to remember about N95s and how they protect you: filter and fit. N95s are made of special filtering materials and the term N95 means that NIOSH has tested the material and proven that it filters out at least 95% of those very small particles in the air that we are worried about, hence the N95. You may also hear the term surgical N95, and a surgical N95 has features that are needed in certain situations in healthcare where there might be more splashes and sprays like surgery, so they're a little bit more resistant to getting that watery material on it and not breaking down. That's not all there is to it though because not every N95 is the same. NIOSH approved N95 are necessary, and you should use a respirator that's NIOSH approved. Your employer is responsible for making sure that this has been approved, and we've put a link to the NIOSH website in the comments so that you can learn more about which respirators, which N95s in particular, are approved by NIOSH. The other part of it is that they all have filtering material but they may not all fit your face the same. For example, NIOSH approved N95s are going to have two straps that go around your head and not loops that go around the ears because they aren't able to give you the good fit and seal that you need. You also need to have fit testing to make sure, like clothes, that they fit your face the way they're supposed to. We're going to talk about that in just a minute in more detail because it's a really important step. But let's talk first about how your N95 works. N95s are designed to filter out certain sizes of particles including droplets in the air before that air reaches your mouth, your nose, and your lungs. And we need that in healthcare because some of those droplets might be carrying a virus, which we talked about in an earlier episode. N95s can do this job because of the filtering material but also because of how they fit. They're put together in a way that makes sure that all the air that you're breathing in goes through that filter first. And in order to be certain that that's happening, you have to find an N95 model that fits your right. We do that with a fit test. The first step of a fit test is actually a medical evaluation. It makes sure that the N95 is the right respirator for you, that it's not going to hurt you, or you don't have a medical condition where it would be made worse by using an N95. And your employer, again, is responsible for making sure that you get that medical evaluation done before the fit test. Then, you need to be fit tested for each model that you might wear at work to make sure that it fits right around your face because if it doesn't, you might breathe in air through gaps around the edges of the respirator and then that air won't be filtered, and it could end up making you sick. So that snug fit, it's not having to be super-tight. It's not supposed to hurt you, but it should be a snug fit all the way around and that's important for getting all of your air through the filter. It's also important to put on, or don, the N95 correctly and to check, each time, the seal of your N95 with something we call a user seal check. We're going to talk about that in another video. Most N95s are also good at blocking your own respiratory droplets when you wear them so that any germs that you might be breathing out don't reach the air and infect other people like SARS-CoV-2, if you're infected and that's one of the main reasons we really like to use N95s in healthcare. They do two jobs at once. They protect you from viruses, but they also protect everyone else from any viruses that you might be carrying and breathing out. So because N95s are specially tested and fitted to filter the air we breathe before we breathe it in, we know that almost all these droplets that others are breathing out, some which might have virus inside, will be caught by the filter before getting to us. And this protects us from getting sick even when we're around people and very close to people who are breathing out a lot of respiratory droplets with a lot of virus inside of them like our patients with COVID-19 and other people who might be infected. So as always, thank you for joining us. Be sure to follow up with us on Twitter, on Facebook and, of course, on our website cdc.gov/projectfirstline. We will see you guys back at the next episode.