*Clearing and Sealing Protective Mask*
23 March 2003
You should already have cleaned your mask and conducted a mask fitting. Now you are in an environment that has become contaminated. How do you put your mask on without breathing in any more contaminates? Easy. First, when you realize the area around you is unsafe you IMMEDIATELY stop breathing and close your eyes. Grab your mask and put it on. This should be easy for you since you have fitted your mask and have practiced putting it on in a hurry. OK, so you’ve got your mask on, how do you make sure you’ve got a good seal? You’ve first got to clear your mask. This is done by covering up the outlet valve with one hand. Each type of mask has a different location for the outlet valve, but it is generally located in the front towards the bottom of the mask.
With the outlet valve covered, blow out as much air as you can. You should feel air escaping around the edges of the mask, it may even sound somewhat like a "fart". This is good. Now, before you can begin to breathe normally, you have to "seal" your mask. To do this, you take the hand that was covering the outlet valve and move it so you are covering the inlet valve (Filter Canister).
Now, breathe in. If you have a proper seal, you should feel the mask suction to your face. If you do not get the suction effect, make sure that there is no hair or any other obstructions around the edges of the mask where it should be just touching skin. Repeat the process. Once you have the suction effect, ensure that all straps are sufficiently tightened to hold the mask in place and continue to breathe normally. By the way, you can now let go of the mask and continue about your business.