A qualitative fit test (QLFT) for respirators may only be used for which type of respirator?

A qualitative fit test (QLFT) is designed to assess the fit of respirators, specifically those with tight-fitting facepieces. This testing method relies on the subject's ability to detect a specific odorous or irritating substance while wearing the respirator. The fit test is suitable for half-mask respirators, which include both half-face and full-face respirators, though the qualitative fit test is specifically recognized for half-face models.

The reason half-mask respirators are the focus here is due to their structure and the testing method itself. QLFT is not approved for use with powered air-purifying respirators (PAPRs) or other types of respiratory protection that do not fit tightly to the face. This ensures that any fit test conducted will yield reliable results, as the nature of the seal against the face is critical to the respirator's effectiveness, which is well-represented in half-face designs.

Thus, when conducting a qualitative fit test, it is essential to limit its application to half-face respirators to maintain testing standards and reliability in assessing proper fit.