字幕列表 影片播放 列印英文字幕 When you must wear a respirator to protect yourself against airborne contaminants in your workplace, it is very important to follow proper procedures for putting it on and taking it off. The process of putting on and taking off your respirator is also referred to as “donning and doffing.” Respirator manufacturers supply instructions on how to properly don and doff (put on and take off) each respirator they produce. The manufacturer also supplies instructions on how to properly conduct a user seal check. A “user seal check” is a way to verify that the respirator has been properly positioned on your face to assure a proper seal. Sometimes, workers confuse the term “user seal check” with the term “fit test,” which is different. A user seal check is not a substitute for a fit test, which is a more involved process that uses a test agent or instrument to verify the respirator’s fit. A fit test must be performed before you wear a respirator for the first time and at least annually thereafter. A user seal check must be performed each time you put on a respirator to check that it has been donned correctly. Remember, always follow the respirator manufacturer’s instructions for the specific respirator model that you are using. Here are some general instructions for properly donning and doffing and properly conducting a user seal check for the two most common types of respirators. Let’s begin with general instructions for a disposable filtering facepiece respirator, which is often referred to as an “N95” or a “dust mask”: Inspect the respirator, including the straps, for tears or damage. If you find any damage to the respirator, replace it. If your respirator comes out of its original container folded flat, open the folds fully, following the manufacturer’s instructions. Using one hand, place the respirator on your face with the nosepiece at your fingertips, allowing the headbands to hang freely. The nosepiece should span and cover the bridge of your nose, and the respirator should cup your chin. Pull the top strap over your head, resting it high at the back of your head. Pull the bottom strap over your head and position it around your neck and below your ears. Be sure not to criss-cross the straps. Make sure that your mouth and nose are covered by the respirator. If the nosepiece has a metal nosepiece or strip, use both hands to mold the nose strip to conform to the shape of your nose by pushing inward while moving your fingertips down along both sides of the nosepiece. Next, conduct a user seal check. It’s essential to follow the manufacturer’s user seal check instructions because the manufacturer knows the best method for checking their respirator. Generally speaking, the manufacturer’s instructions are based on covering the surface of the respirator, usually with your hands, so that air is prevented from passing through the filtering facepiece. A positive pressure seal check is performed by gently exhaling to see if the facepiece bulges slightly. For a negative pressure seal check, take a quick, deep breath to see if the facepiece collapses slightly. During either test, if air leaks out between your face and the respirator’s faceseal, the respirator may not fit your face properly. One way that you can identify leakage is if you feel air blowing through the seal onto your face or eyes. If you feel leakage, readjust the fit of your respirator and check the seal again. If you cannot achieve a proper seal, you are not protected and should not enter a hazardous area. See your supervisor to determine what the problem may be. When you’re finished wearing the respirator, carefully remove it without touching the exterior, because the exterior may be contaminated. Discard your respirator according to your company’s procedures. Now, let’s explore the general instructions for properly donning and doffing and properly conducting a user seal check for a half facepiece elastomeric respirator, sometimes referred to as a “half mask.” Remember, these are just general instructions. You should always follow the manufacturer’s instructions for the specific respirator model that you are using. To begin, inspect the respirator, including the straps, valves, and gaskets, for loose, missing, or damaged parts. If you find any damage to the respirator, repair or replace it. Then, pull the bottom strap over your head. Place the respirator facepiece under your chin and over your nose, with the narrow part of the facepiece over your nose. Pull the head harness over the crown of your head and adjust its placement until it is stable, but comfortable. Be sure that the neckstrap is flat and smooth against the back of your neck. Adjust the neckstrap, but be careful not to over-tighten the respirator to your face. Next, perform a positive pressure user seal check. Place the palm of your hand over the exhalation valve outlet. Do not push so hard that you distort the natural shape of the facepiece. Exhale gently and hold your breath to create and maintain a slight positive pressure inside the facepiece. If the facepiece bulges slightly and no air leaks are detected between your face and the facepiece, a proper fit has been achieved. If, on the other hand, you detect faceseal leakage, reposition the facepiece and readjust the straps, and then retest. If you cannot achieve a proper seal, you are not protected and should not enter a hazardous area. See your supervisor to determine what the problem may be. Next, perform the negative pressure seal check. Cover the respirator cartridges or filters with the palms of your hands. Inhale gently. If you feel the facepiece collapse slightly and pull closer to your face with no leaks between the face and facepiece, a proper seal has been made. If you detect faceseal air leakage, reposition the respirator on your face and readjust the straps, then recheck. If you cannot achieve a proper seal, you are not protected and should not enter a hazardous area. See your supervisor to determine what the problem may be. When you have finished wearing the respirator, carefully remove it by loosening the straps and taking it off without touching the cartridges or filters, because they may be contaminated. Follow your company’s procedures for maintenance of the respirator, including proper cleaning and disinfecting and storage. Remember, respirators must be used in the context of a comprehensive respiratory protection program, according to OSHA standard 29 CFR 1910.134.