There are two basic types of fit tests. Qualitative fit tests use a testing agent, like smoke or smell, to see if a respirator is getting a good seal. Quantitative fit tests count the actual amount of particles that are getting into the respirator.
Qualitative fit tests are easier, less expensive, and less accurate. Quantitative fit tests are more accurate, but require special equipment.
When Qualitative Fit Tests Can Be Used:
Understanding the Required Protection Factor
The required protection factor is the amount of protection required for employees to be below the permissible exposure level (PEL). For instance, if the PEL for a airborne contaminant is 10 ppm, and the atmospheric contamination level is 200 ppm, then the required protection factor is 20 or greater.
Qualitative fit tests may only be used on negative pressure respirators when the required protection factor is 10 or lower, and the atmosphere is not IDLH.
When Quantitative Fit Tests Must Be Used:
Quantitative fit tests are required for negative pressure respirators when the required protection factor is greater than 10, or the atmosphere is immediately dangerous to life and health.
- 29 CFR 1910.134 - Respiratory Protection
- 29 CFR 1910.134, Appendix A - Fit Testing Procedures
- OSHA Respirator Compliance Guide