Validity of WPF study defended (Letter to the Editor).
Am Ind Hyg Assoc J 1996 Apr; 57(4):395-396
In a letter to the editor, authors of Workplace Evaluation of a Disposable Respirator in a Dusty Environment (Applied Occupational and Environmental Hygiene 2(2): pages 53 to 56, 1987) discuss the quantitative fit test used for the respirator used, and characteristics of the material being measured, a cement product. The quantitative fit tests were conducted before the start of each work shift to ensure that gross leakages were identified and corrected before data collection began. The effect of humidity in the mask on the cement product was considered. Cement product in the inside of the mask samples would have been in a humid environment which would have included moisture chemically trapped in the cement matrix. A sample of the concrete patching compound packaged at the time of this study was tested to evaluate the moisture content after exposure to high relative humidity. Nineteen filters in two piece cassettes were loaded with the material from an aerosol created by a sonically fluidized bed generator and then subjected to high relative humidity conditions. Filter loadings were similar to those of the in mask air samples. Results indicated that even under a worst case scenario, the contribution of moisture would have been small.
NIOSH-Author; Industrial-factory-workers; Respiratory-protective-equipment; Dust-exposure; Respiratory-protection; Dust-sampling; Cements
American Industrial Hygiene Association Journal