Qualitative vs Quantitative Fit Testing: Which should you use?
A plain-English breakdown of when you can use qualitative testing and when OSHA requires quantitative.
The Core Difference
When you boil it down, Qualitative testing relies on a person's senses, while Quantitative testing relies on a machine.
Qualitative (QLFT)
This is a simple pass/fail test. We put a hood over the employee and spray an irritant (like saccharin, banana oil, Bitrex, or irritant smoke). If they can taste or smell it, the mask isn't sealing.
* Best for: Half-face negative pressure respirators (like N95s) and environments where the required fit factor is 100 or less.
* Pros: Fast, inexpensive, can test multiple people at once.
* Cons: Relies on the employee being honest about whether they taste the solution.
Quantitative (QNFT)
This uses a specialized machine to calculate the exact amount of leakage into the mask. It spits out a numeric "fit factor."
* Best for: Full-face respirators, or half-face reusable respirators used in highly hazardous environments.
* Pros: Indisputable numeric proof. No bluffing. No subjectivity.
* Cons: Slower (tests one person at a time), slightly more expensive.
Which do you need?
If you're using basic N95s or half-masks in standard hazard environments, qualitative is usually the most practical choice. If you're dealing with extreme hazards requiring full facepieces, OSHA requires quantitative testing.
Need help deciding? Contact Onsite Fit Testing to review your specific respirators and hazards.