What is a negative pressure check in the context of respirator fit testing?

In the context of respirator fit testing, a negative pressure check specifically involves the user breathing in while exerting negative pressure to assess the effectiveness of the respirator's seal. During this process, the wearer inhales sharply, creating a vacuum effect that should draw the respirator facepiece inward if a proper fit is achieved. This action helps to ensure that there are no leaks between the respirator and the user's face, indicating that the respirator will provide adequate protection against airborne contaminants.

This method is essential for confirming that the respirator is fitted correctly to the individual's face shape and size, thereby maximizing its protective capabilities. Failure to create this negative pressure indicates that adjustments may be needed in the fit or positioning of the mask.

While other options might involve various types of seal checks or assessments for fit, they don't accurately describe the specific mechanics of the negative pressure check, which is why the chosen answer is the most appropriate in describing this fit testing method.