Learn how to properly use an N95 respirator
As wildfire smoke pervaded the capital region this week and the air quality index plunged into its worst levels, Sacramento officials and others are handing out free respirator masks to residents to help them reduce the pollutants they’re breathing into their lungs.
The respirators, however, are completely ineffective — even harmful — if users don’t take the time to learn how to use them properly or to understand their limitations, say Cal-OSHA regulators and others who train people to use them properly. That’s because users might be tempted to stay outdoors longer because they think they’re protected.
“There could be a real false sense of security if somebody puts one on and they’re not wearing them properly,” said David T. Dyjack, a certified industrial hygienist who leads the National Environmental Health Association. “That’s why I always say: If you can, stay indoors. If you can’t, of course wear a respirator, but of course, understand the use and limitations.”
For instance, Dyjack said respirators offer no protection to bearded men. A human hair measures about 75 microns in width. The fine particulates in the air can be as tiny as a fraction of 1 micron.
That means that anyone with facial hair will not be able to achieve the tight seal needed to offer any protection, Dyjack said, because unfiltered air can glide through the gaps between hair and face.
At SacBee.com, Cal-OSHA’s David Hornung demonstrates how to put on the N95 respirator — one of the most commonly used devices for filtering out smoke particulate — and how people test whether they have an effective seal.
Here’s what Hornung, a senior safety engineer, suggests residents do to ensure they’re correctly using respirators:
▪ Check the front of the mask for an N95 or P100 rating. The N95 respirators are 95 percent effective against particles in the air that are 0.3 microns or larger, and their N95 rating is given to them by the agency that tests them, the U.S. National Institute for Occupational Safety and Health.
▪ Read instructions on how to use the respirator and follow them. Also read and understand the device’s limitations.
▪ All N95 masks will have two straps. Use both and place them properly. (One strap goes over and around your head, resting against your head and above your ears, and the other one over and around your head, resting against your head below your ears.)
▪ Position the mask to get the tightest seal around your face. With your hands, push the nose piece down. Test the seal as the manufacturer recommends.
For the mask Hornung tested, the manufacturer had him cover the facepiece with his hands, breathe in and determine whether he could feel air being sucked into through gaps around the facepiece. After that, he expelled air and checked whether he could feel air coming out under the sides of the facepiece. Air quality experts said people should also understand the limitations of the masks. For instance, they said, they don’t protect users from gases or vapors. In some cases, respirators can be used only once, experts said, and if you take them off, they must be discarded. Other respirators can be used only for one day, or until they show visible signs of dirt and debris.
Dyjack warned against using the mask while running or doing other exercise, if you’re asthmatic or if you have a serious medical condition. It takes effort to pull air through the mask, he said, and it can feel like you’re drowning if you overexert yourself or hyperventilate.
“I would never want anyone to think that just because they have a mask on, they can stay out all day,” Dyjack said. “Respirators are sophisticated pieces of personal protective equipment, and they need to be respected.”
Don’t confuse respirators with surgical masks, Dyjack and other experts said. Surgical masks offer no protection against fine particulate, Dyjack said. They are intended to protect patients from any germs their clinician has.
On Thursday, the Air Quality Index was “very unhealthy” in the overall Sacramento region for the eighth day this year, but three of 14 air monitoring stations in the region — Lincoln, downtown Sacramento and Woodland — actually jumped into the index’s worst level: hazardous. Officials advised staying indoors and avoiding any prolonged physical exertion outdoors.
A change in wind direction is expected to provide a slight improvement in air quality over the weekend, said Lori Kobza, a spokesperson for the Sacramento Air Quality Management District, but winds will likely shift back this way Monday. Weather forecasts have said the region could get rain Tuesday or Wednesday of next week, Kobza said, and if we do, that will dissipate the particulate matter.
“It will pull all those particles down into the dirt,” Kobza said. “We live in a bowl, and right now … the lid is on top of the bowl. That lid is the pressure system, and right now it’s clamped down over all of Northern California.”
UC Davis researcher Keith Bein has seen worse. He has been studying the air and ash left in urban areas after devastating wildfires swept through in an effort to discover what gases and particulate matter wildfire releases when it burns through an urban neighborhood.
He was in Santa Rosa’s Coffey Park months after last year’s Tubbs Fire, and he felt no need to wear his respirator because the level of particulate matter was no different than on an average day in Sacramento.
But when he went to Redding’s Lake Keswick Estates one or two days after the Carr Fire devastated the neighborhood, he wore the respirator that UCD’s environmental safety team had specially fitted for him.
“The fire ... was still all around the place,” he said. “The concentration of PM in the atmosphere was so high that I’d never seen anything like it before. We’re talking 500 micrograms per cubic meter, whereas that area may typically see something like 10. It was a factor of 50 higher. It was all day and all night, and there was no way ever to escape. “
The Bee’s Phillip Reese contributed to this report.