What does a negative pressure check evaluate?

A negative pressure check is designed to evaluate the fit of the respirator. This check ensures that the respirator forms a proper seal against the wearer’s face, preventing contaminated air from entering. When the wearer inhales, the negative pressure created should cause the respirator to collapse slightly against the face, indicating that it is effectively sealing. This is essential for ensuring proper respiratory protection, as a poor fit can expose the wearer to harmful substances in the environment.

In this context, the other options do not accurately reflect what a negative pressure check assesses. For instance, the supply of air pertains to the functioning of the respirator’s air supply system rather than its fit. The quality of the filter involves assessing its effectiveness in trapping harmful particles, which is not evaluated by the negative pressure check. Similarly, the durability of the facepiece relates to the material strength and condition over time, which is unrelated to the fitting process. Hence, the correct focus of a negative pressure check is specifically on the fit of the respirator.