Significance and Use
5.1 This test method is normally used to evaluate the barrier effectiveness against penetration of liquids through materials, seams, closures, or other planar assemblies used in protective clothing and specimens from finished items of protective clothing.
5.1.1 Finished items of protective clothing include gloves, arm protectors, aprons, coveralls, suits, hoods, boots, and similar items.
5.1.2 The phrase “specimens from finished items” is permitted to include continuous regions of protective clothing items as well as seamed or other discontinuous regions of protective clothing.
5.1.3 The types of specimens are limited to those that are relatively flat (planar) that are capable of being sealed in the test cell specified in this test method without peripheral leakage.
5.2 A substitute challenge liquid (for example, water or isopropanol) is appropriate in some cases to generalize material penetration resistance to liquids. However, it is possible that differences in chemical and molecular properties (for example, surface tension) may lead to different results.
5.3 In addition to the failure mode where a liquid finds a pathway for penetration through a void, imperfection, or defect in material or clothing subassembly, some selected chemicals cause degradation of barrier material, film, or coating, leading to penetration over extended periods of contact.7
5.4 Five different procedures for how the specimen is exposed to the liquid are provided in Table 1. In this test method, all procedures involve liquid exposure that is continuous over the duration of the test. These procedures entail different hydrostatic pressures and durations of liquid exposure.
5.4.1 Procedures A, B, and C apply a set pressure (6.9 or 13.8 kPa [1 or 2 psig]) for a specified period of time (1 or 10 min) over a 15 or 60 min liquid exposure time.
5.4.2 Procedures A and B represent the originally established methods of liquid contact developed by the National Institute for Occupational Safety and Health, where Procedure A involves the application of a test pressure (13.8 kPa [2 psig]) that has been found to discriminate the liquid barrier performance of materials, while a lower pressure (6.9 kPa [1 psig]) is used for Procedure B to accommodate materials that exhibit ballooning or extension when the 13.8 kPa (2 psig) pressure is applied.8,9 Both procedures entail exposure of the specimen for 5 min at ambient pressure followed by 10 min of exposure of the specimen to the test pressure.
5.4.3 Procedure C was developed to account for potentially longer exposures where failure may also occur as the result of material or assembly degradation. Procedure C uses a 13.8 kPa (2 psig) test pressure for a portion of the test where the specimen is first exposed to the liquid at ambient pressure for 5 min, followed by 1 min at 13.8 kPa (2 psig), and continuing for 54 additional minutes at ambient pressure.
5.4.4 Procedure D involves the sequential increase of pressure from ambient (0 kPa [0 psig]) to 68.9 kPa (10 psig) in increments of 3.5 kPa (0.5 psig) in 1 min intervals until liquid penetration is observed at a specific test pressure. The time interval between changes in pressure is set at 1 min to coincide with the time of applied pressure in Procedure C.
5.4.5 Procedure E permits the test method user to specify the pressures and duration of the specimen’s exposure to the liquid.
5.5 Different results are reported by the different procedures.
5.5.1 Procedures A, B, and C results are reported as “pass” or “fail” for each replicate. Passing results indicate that no liquid penetration was observed over the duration of the test exposure.
5.5.2 Procedure D results are reported as the test pressure at which liquid penetration was observed for each replicate.
5.6 The choice of pressure/time sequence and type of test result are dependent on the objectives of the testing.
5.6.1 Procedure C is specified in several different National Fire Protection Association standards for establishing the minimum barrier performance of protective clothing materials, seams, and closures of first responder protective clothing.
5.6.2 Procedure D may be used when the pressure where penetration occurs is sought without a set pressure pass/fail criterion. Procedure D also has utility for assessing the robustness of protective clothing materials and assemblies as part of quality systems. It is also possible to use Procedure D to supplement the pass/fail results provided by Procedures A, B, and C.
5.6.3 Procedure E permits setting a specific sequence of pressure/time exposures based on the specific needs for the testing.
5.6.4 In this test method, a hydrostatic pressure is applied but does not necessarily correlate with a mechanical pressure against a semi-rigid or rigid surface.
5.6.5 It is recommended that a human factors investigation, hazard/risk exposure assessment, or similar study be conducted to determine the most suitable procedure for relating the choice of a specific procedure for measuring protective clothing material liquid penetration resistance to the intended protective performance of the clothing material.
5.7 This test method permits the use of a retaining screen for preventing the overextension of a specimen as pressure is applied. However, it is important that the selected retaining screen does not interfere with the observation of liquid penetration or affect the sealing of the specimen in the test cell.
5.8 A critical feature of the test is how the specimen is sealed in the test cell. Inadequate sealing of the specimen can lead to a false result (observed liquid penetration that is due to the method of sealing rather than penetration through the specimen). It is recommended that any special means used to seal specimens in the test cell be validated for providing sufficient integrity of the specimen in the test cell, for not contributing to specimen damage, and for not interfering with the observation of liquid penetration. Special means used to seal specimens in the test cell must be documented in the report.
5.8.1 The proper technique of sealing specimens can vary based on the physical and chemical properties of the liquid and/or material.
5.8.2 Two cell options for sealing are typically utilized. Option 1 contains most of the specimen perimeter clamped between two flat gaskets. Option 2 suspends the specimen perimeter completely outside the sealing means to allow any leaks the ability to drip off the specimen. Alternative methods are permitted as long as proper sealing is achieved.
5.8.2.1 Option 1 may be advantageous when the physical and chemical properties of the liquid and/or material make encapsulation of the outer perimeter of the specimen necessary, such as when both outer surfaces of the specimen are highly absorbent of the challenge liquid. Or, the surface tension of the challenge liquid is sufficiently low that any leak will effectively drain the liquid chamber within the test period.
5.8.2.2 Option 2 may be advantageous when seams and other planar imperfections make obtaining a flat seal difficult and at least one outer surface of the specimen is not highly absorbent of the challenge liquid.
Note 2: A rough evaluation of absorbency or surface tension is the time for which a bead of liquid will remain on a given surface.
5.9 A minimum number of three test specimens is established for this test method. However, it is also appropriate to establish sampling plans based on a specific acceptable quality limit using a larger number of specimens, depending on the application of the test method. Potential sampling plans for this approach are found in MIL-STD-105E, ANSI/ASQC Z1.4, and ISO 2859-1.
5.10 This test method does not address the liquid penetration of full protective clothing or ensembles. Use Test Method F1359/F1359M to provide a complete evaluation of the liquid integrity of protective clothing or ensembles, particularly areas of the clothing or ensembles that cannot be directly assessed by this test method, such as interface areas between different items of clothing and equipment.
Scope
1.1 This test method is used to test specimens of protective clothing materials, assemblies such as seams and closures, or interfaces used in the construction of protective clothing. The resistance to visible penetration of the test liquid is determined with the liquid in continuous contact with the normally outside (exterior) surface of the test specimen.
1.2 This test method includes different procedures for maintaining the liquid in contact with the test specimen in terms of the length of exposure and the pressure applied. Suggestions are provided for how to select an appropriate procedure for liquid contact.
1.3 In some cases, significant amounts of hazardous materials will permeate specimens that pass the penetration tests. For more sensitive analyses, use either Test Method F739 or F1383 to determine permeation.
1.4 This test method does not address penetration of vapors through protective clothing materials.
1.5 This test method is not applicable to non-planar protective clothing materials, interfaces, or assemblies such as the fingertips or crotch areas of gloves, which are possible failure points.
1.6 This test method does not address the liquid penetration resistance of full protective clothing items or ensembles. Use Test Method F1359/F1359M for this purpose.
1.7 The values as stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information only.
Note 1: Past testing allowed different screen designs to be used without sufficient documentation to allow duplication. The results with recommended screens and with documentation to allow duplication may be different from previous results.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazards are given in Section 7.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
