What is being tested when a worker closes off the respirator inlet and inhales for 10 minutes?

The process of closing off the respirator inlet and inhaling for a period of time is a method used to assess the effectiveness of the respirator's seal against the wearer's face. This method is known as a negative pressure test. During this test, if the seal is effective, the wearer will feel resistance or a slight vacuum, indicating that no air is leaking in. This step is crucial for ensuring that the respirator provides the necessary protection by preventing contaminated air from entering.

When conducting this test, it's important to verify that the respirator fits properly and creates a satisfactory seal, which is essential for preventing exposure to potentially harmful airborne contaminants, such as asbestos. A negative pressure test is particularly relevant in ensuring the safety and health of workers who may be exposed to hazardous materials.

The other options represent different testing methods or concepts. A positive pressure test involves ensuring that air flows out of the respirator, indicating a proper seal under slightly elevated pressure, while a fit test typically encompasses a broader evaluation of how well the respirator conforms to the shape of a worker's face. An airflow test would measure the air coming through the respirator but is not specifically about seal integrity. Understanding these distinctions is important for proper respirator selection and safety practices in environments