What role does a user seal check play in the use of tight-fitting respirators?

A user seal check is a crucial procedure in ensuring the effectiveness of tight-fitting respirators. This check is conducted to confirm that the respirator forms a proper seal against the wearer's face, which is essential for the device to function as intended. A proper fit helps to prevent contaminated air from leaking into the respirator. If the fit is not adequate, the user may be exposed to hazardous airborne contaminants, undermining the protection provided by the respirator.

The process typically involves two types of checks: the positive pressure check, where the wearer exhales gently to see if the facepiece bulges slightly, and the negative pressure check, where the wearer inhales to ensure the facepiece collapses slightly. These checks should be done every time the respirator is worn to ensure that it continues to fit well throughout usage.

While other options relate to aspects of respirator use, they do not specifically address the essential function of user seal checks. Cleaning the respirator, evaluating breathing capacity, or assessing chemical exposure levels are not directly related to verifying the fit of the respirator and ensuring it provides a secure barrier against inhalation hazards.