Penetration of liquid through small holes using a standard test method.
Hewett-DJ; Berardinelli-SP; Noonan-GP; Hall-RC
American Industrial Hygiene Conference and Exposition, May 15-21, 1993, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 1993 May; :2
The American Society for Testing and Materials (ASTM) Penetration Test Method F903-87 is regarded as a standard method to qualitatively test chemical protective clothing (CPC) for pinholes. The method uses atmospheric (zero gauge) and 6.9 kPa (1.0 psig) pressure tests. The purpose of this study was to determine to what degree hole diameter and surface tension variables affect the determination of a pass/fail result. An additional pressure test of 13.8 kPa (2.0 psig) was added to the protocol for this study. (The 13.8 kPa test was discontinued and replaced by the 6.9 kPa pressure test in the 1987 revision of ASTM F903.) Four challenge liquids were selected to represent a wide range of surface tensions encompassing those typical of blood and body fluids: 73.4, 45.3, 29.9 and 19.4 dynes/cm. A Mylar polyester film served as a barrier. Holes were melted through the film and were measured by electron microscopy in the range of 4 to 232 /u/m. Regression analysis shows that surface tension and hole size are significant (p < .0001) predictors of test outcomes (pass/fail) at atmospheric pressure. At atmospheric pressure, liquids with low surface tensions were more likely to penetrate smaller size Mylar film holes than higher surface tension liquids. The 6.9 kPa pressure test results (99% failures) and 13.8 kPa results (100% failures) were not dependent upon hole diameter and surface tension effects. This indicated that a 6.9 kPa test provides the same level of utility as the discontinued 13.8 kPa test, for a Mylar barrier challenged by the range of hole sizes and surface tensions used in this study.
NIOSH-Author; Materials-testing; Protective-clothing; Personal-protective-equipment; Skin-protection; Physical-properties
American Industrial Hygiene Conference and Exposition, May 15-21, 1993, New Orleans, Louisiana