Definition - What does user seal check mean?
A user seal check is a procedure that is performed to confirm that a tight-fitting respirator is adequately sealed against the face of the wearer. Each wearer of this type of personal protective equipment (PPE) must perform a user seal check whenever he or she puts on a tight-fitting respirator. During a user seal check, the wearer will assess the adequacy of the mask facepiece's seal. The seal check may be performed using a positive or negative pressure check as prescribed by U.S. Department of Labor standards or the procedure recommended by the respirator's manufacturer.
SureHire explains user seal check
A tight-fitting respirator is only effective at protecting the wearer from airborne contaminants if it fits securely against the wearers face, forming a leak-proof seal. To test for a proper seal, a wearer may conduct either a positive or negative air pressure test.
To perform a positive user seal check, the user puts on the mask then exhales while covering the mask's openings or exhaust ports. If the mask is securely sealed, no air should escape around the edges of the mask. To perform a negative pressure check, the user again cover the mask with his or her hands. Then with all openings to the mask covered, he or she inhales. When the wearer inhales, no air should leak in through the edges of the mask if it is sealed properly.
For some types of masks the positive or negative pressure test may not be suitable. If the manufacturer's recommendations indicate that these tests are not effective, then the test prescribed by the manufacturer should be used instead.
If an initial user seal check fails, the problem can often be alleviated by adjusting the mask against the wearers face. If these adjustments are not successful in eliminating all leaks, then the user should not enter any contaminated areas. He or she will need to be refitted with a mask that provides a safe seal.