Quantitative Fit Test (QNFT)
Definition - What does Quantitative Fit Test (QNFT) mean?
Safeopedia explains Quantitative Fit Test (QNFT)
During the test, a challenge agent is administered outside the face piece and the presence of the agent is detected and counted by an instrument.
There are three types of QNFT:
- Generated Aerosol: Uses corn oil and a photometer-based aerosol detector.
- Ambient Aerosol Nuclei Count: Uses laser technology to measure aerosol concentration inside and outside the respirator.
- Controlled Negative Pressure: Creates a vacuum in the mask and calculates airflow.