[Protective performance and subjective evaluation of N95 filtering-facepiece respirators].
OBJECTIVE
To evaluate the protective performance of N95 filtering-facepiece respirators (FFRs) used widely in China and to investigate participants' subjective evaluation about them.


METHODS
Four models (A1, A2, B1, B2) of N95 FFRs from two manufactures were chosen to measure the filter penetration and inhalation resistance. Inward leakage was measured by Condensation Nuclei Counting method (CNC) in 50 participants selected using the Chinese respirator fit test panel. Each participant was asked subjective feelings after wearing a respirator by questionnaire survey.


RESULTS
The filter penetration and inhalation resistance of four FFRs complied with national standard (GB 2626-2006). The geometric mean fit factors (GMFFs) for four models were 20.9, 14.6, 74.0, 49.1 and there passing rates were 4%, 4%, 42%, 10%. All of four models had bad seal performance, especially the passing rate of A1 and A2 were lower than 10%. The self-feelings about the resistance for FFRs had no significant difference (P > 0.05). The results indicated that B (B1 and B2) has a better fit than A (A1 and A2) according to participants' subject evaluation (P < 0.05). The folding style respirator (B2) was significant more comfortable than the cup style respirator (B1). The subjective feeling of respirators leakage by participant was poor consistent with objective inward leakage test. The kappa index was 0.067 (95%CI: -0.029∼0.163, P = 0.18) and the consistent rate was 50%.


CONCLUSIONS
The poor seal performance was the biggest problem of N95 FFRs in Chinese market. Respirators should be resigned or improved rely on Chinese facial features. Dust workers should choice a fit respirator according to the result of objective leakage test rather than subjective feeling of leakage.
School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Lu-man
LM
Jiang
Yan-yan
YY
Yu
Yi
Y
Rong
Xiu-qing
XQ
Cui
Xin-yan
XY
Wang
Wei
W
Lu
Ying
Y
Tao
Wei-hong
WH
Chen
D000328:Adult; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000517:prevention & control*; D008297:Male; D008422:Materials Testing / Q000379:methods; D016273:Occupational Exposure / Q000517:prevention & control*; D012134:Respiratory Protective Devices; D055815:Young Adult