Additionally, a major respirator manufacturer has stated:
Ideally, respirator performance as described by 5th percentile values should be based on variability caused by the fit and filter efficiency of the respirator alone.
Thus hazardous leakage of a contaminant into a respirator can result when either or both of excessive filter leakage or excessive face-seal leakage occur. Employers are responsible for testing for face-seal leakage with procedures known as fit tests, which
can be either qualitative (QLFT) or quantitative (QNFT).[1] In several OSHA rulemakings, NIOSH has suggested numerous factors that affect respirator effectiveness for individual wearers in the workplace.[2][3]
NIOSH recognizes that the likelihood of each respirator wearer achieving adequate
protection during each respirator wearing is a strong function of the inherent protec-
tive capabilities of the make and model respirator used. In addition, the Institute
also recognizes that the likelihood of achieving adequate wearer protection is also a
strong function of two types of determinant factors:
the determinant factors affecting excessive face-seal leakage at the time of the
initial and periodic fit factor screening (fit testing with QLFTs or QNFTs)
the "point-of-use" determinant factors affecting both excessive filter leakage
and excessive face-seal leakage during the time of each wearing.
As generally performed, QLFTs or QNFTs are performed to detect only face-seal
leakage existing at the time of testing. They are not capable of detecting excessive
filter leakage. No matter how effective they are or how well they are performed, fit
tests can only help identify compromised protection resulting from the first type of
factors for face-seal leakage. The fit tests cannot detect excessive filter or face-seal
"National Institute for Occupational Safety and Health: Comments to OSHA for Docket H-160:
Health Standards: Methods of Compliance, (June 1983), p. 7.
- ↑ Gosselink, D. W., Wilmes, D. P, and Mullins, H. E.: Workplace Protection Factor Study for Airborne Asbestos (a.k.a. The Shiloh Brake Study conducted by representatives of the 3M Company), presented at the American Industrial Hygiene Conference, Dallas, Texas (May 1986), p. 7.
- ↑ For example, but not limited to, 29 CFR 1910.134(e)(5).
- ↑ National Institute for Occupational Safety and Health: Supplemental Report to OSHA for Docket H-049A: Evaluation of Quantitative and Proposed Qualitative Screening Tests for Inadequate Fit Factors of Respirator Users, (October 1982), pp. 20-21.
