How often must respirators be "user seal checked"?

The correct answer states that respirators must undergo a "user seal check" every time they are put on. This practice is crucial for ensuring that the respirator fits properly against the user's face, creating an effective seal to prevent unwanted air from entering the respirator. A proper fit is vital in protecting the wearer from inhaling hazardous substances such as asbestos fibers.

Conducting a user seal check each time helps to identify any issues with the fit that may arise due to facial changes, such as beard growth or changes in facial structure, as well as environmental factors that may affect the integrity of the seal. This routine check minimizes the risk of exposure to harmful substances, thereby enhancing safety in the workplace.

Alternative frequencies such as daily, weekly, or monthly do not provide the necessary assurance that the seal is intact before each use. A user could be exposed to dangerous conditions if a seal is not properly checked each time the respirator is donned. Therefore, the requirement for a user seal check before each use is a vital safety measure in the use of respirators, particularly in environments where asbestos exposure is a concern.