Which type of respirator must be tested for fit?

Air-purifying respirators must be tested for fit because proper fit is essential for these devices to function effectively. They are designed to filter harmful particles, gases, or vapors out of the air, and if the respirator does not fit correctly, there can be leaks around the edges, reducing the level of protection provided.

Fit testing ensures that the respirator seals properly to the face of the user and that they can operate safely within an environment where contaminants are present. Since air-purifying respirators rely on a good seal to be effective, it is crucial to assess the fit for various facial shapes and sizes to safeguard the user's health.

Other types of respirators, such as self-contained breathing apparatus and atmosphere-supplying respirators, typically provide a separate source of clean air and might not require fit testing in the same way since they do not rely on filtering contaminated air. Disposable masks, on the other hand, are often designed for one-time use and are made to fit a range of users without the same concern for a tight seal that fit testing would address.