ISO 17491-1:2012 Protective clothing - Test methods for clothing providing protection against chemicals. Part 1: Determination of resistance to outward leakage of gases (internal pressure test)

First edition. ISO 17491-1 was prepared by Technical Committee ISO/TC 94, Personal safety — Protective clothing and equipment, Subcommittee SC 13, Protective clothing. This edition of ISO 17491-1, together with ISO 17491-2, ISO 17491-3, ISO 17491-4 and ISO 17491-5, cancels and replaces ISO 17491:2002 which has been technically revised. — 12 p.
This part of ISO 17491 specifies a method to be performed either at minimum test settings (Method 1) or at more rigorous test settings (Method 2), for assessing the resistance of a gas-tight suit to outward leakage of air through, for example, essential openings, fastenings, seams, interface areas between items, pores and any imperfections in the construction materials.
This test does not simulate penetration by gases in an inward direction. Although the danger to the wearer arises from leakage in an inward direction, this test method assesses the outward leakage of air after the gastight suit has been inflated so as to stretch the construction material, thereby enabling the test method to detect very small imperfections, such as holes, splits or tears.