N95 masks protect against dangerous fine particulate matter, including from wildfire smoke, according to federal environmental authorities. When worn correctly, certified N95 masks block 95% of airborne particulates from entering the respiratory system. The masks are certified by the National Institute for Occupational Safety and Health, which is responsible for approving respirators for U.S. workplaces. Short-term exposure to wildfire smoke can lead to difficulty breathing and more serious respiratory and cardiovascular conditions. The Colorado Sun partners with Gigafact to produce Fact Briefs — bite-sized fact checks of trending claims.