Suitability survey on N95 filter masks for public health emergency personnel / 上海预防医学

ABSTRACT

Objective To assess the suitability of N95 masks for public health emergency personnel, and to compare the consistency between mask suitability test result and subjective evaluation of mask air tightness so as to guide scientific selection and use of protection masks for emergency personnel. Methods By ambient aerosol condensation nuclear counter method, qualitative suitability test was done among 235 public health emergency personnel from both municipal and district disease control centers.Questionnaires were conducted among them for investigation and comparison of their subjective evaluation of mask air tightness and mask suitability test results. Results Of the 235 subjects, 160 passed the suitability test with the pass rate being 68.1%. With various wearing actions for the test, the subjective evaluation for mask air tightness was compared with suitability test pass rate in terms of consistence, the kappa value range being from -0.09 to 0.43.The kappa value of the action 5 (loudly speaking) was above 0.4, while the kappa values of other 6 actions were all below 0.4.Both kappa value (0.09) and consistency rate (49.7%) were the lowest for action 8 (normal breathing) among all test actions. Conclusion The accuracy of the subjective evaluation for air tightness of the mask proves to be poor, unable to reflect the true protective effect and unable to substitute the suitability test.It is advised that the public health personnel should rely on the suitability test results to correctly choose and use suitable respiratory protective products.