Respiratory Fit Test
A respiratory fit test is a procedure used to assess the effectiveness of a respirator or respiratory protective device in creating a proper seal between the respirator and the wearer's face. This test is crucial to ensure that the respirator provides adequate protection against airborne contaminants, such as dust, chemicals, or infectious agents. The fit test determines whether the respirator can prevent the entry of these contaminants into the respiratory system.
Qualitative Fit Test
Qualitative Fit Test (QLFT): In a qualitative fit test, the wearer is exposed to a test agent, which is typically a harmless substance like saccharin or Bitrex. The test subject wears the respirator, and if they can taste or smell the test agent while performing specific exercises (such as speaking, moving their head, and breathing deeply), it indicates a poor fit. This type of fit test is often used for half-face respirators, N95 respirators, and other filtering facepiece respirators.
Quantitative Fit Test
​A quantitative fit test uses specialized equipment to measure the concentration of particles inside and outside the respirator. The fit testing machine quantifies the fit by comparing these concentrations. The fit factor (the ratio of particles outside to inside the respirator) should meet specific standards for the respirator to be considered adequately fitted. QNFT is often used for full-face respirators, powered air-purifying respirators (PAPRs), and other more complex respiratory protection devices.
