5.1 The purpose of this specification is to establish a recognized criterion for “waterproofness” in terms of a minimum hydrostatic resistance. The necessary definitions to provide a common understanding of the meaning of this characteristic when it is used to describe a fabric coated with rubber or plastics are also given. The specification does not cover requirements for water repellency or water resistance of fabrics coated with rubber or plastics.

This specification establishes the minimum requirements for the hydrostatic resistance or "waterproofness" of fabrics coated with rubber or plastics. This document does not cover water repellency or water resistance of the same materials. The test specimens should be cut to specifications and at random from a roll of coated fabric. The hydrostatic tester should be able to apply the required amount of pressure and sustain it for a specified time. The apparatus should be equipped with two concentric ring clamps with rounded inside edges to avoid cutting the specimen. The lower clamp should be fitted with a seal to prevent leakage during testing.

1.1 This specification sets forth the minimum requirements for hydrostatic resistance of fabrics coated with rubber or plastics. Coated fabrics satisfying these requirements are considered to be waterproof.

1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.

1.3 The following precautionary caveat pertains only to the test method portion of this specification: 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 and health practices and determine the applicability of regulatory limitations prior to use.