1.1This test method determines the susceptibility of threaded plastic closures to failure due to environmental stress cracking (ESC).

1.2In use, threaded plastic closures can contact agents that appreciably reduce the stress at which cracks form. Examples of such agents are: soaps, detergents, oils, and liquid bleaches.

1.3Major factors that influence environmental stress crack resistance (ESCR) of threaded plastic closures include the closure material(s), closure design, molded-in stress, and applied stress.

1.4This procedure can be applied to all closures, but is particularly applicable to closures made from plastics based on polypropylene (PP) or polystyrene (PS).

1.5The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

1.6This 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 precautionary statements are given in Section 8 and 6.2.

1.7This 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.