ASTM F 2338-09 (2020) is a standard test method for nondestructive detection of leaks in Encasement using vacuum attenuation. This method is suitable for medical apparatus, pharmaceutical, and food Encasement. It can effectively detect the possible leakage of Encasement during transportation and use, and prevent harmful gases, microorganisms, or particles from entering the Encasement. The test operation can be performed semi-automatically, automatically, or manually, and the test results are judged by the pressure change in the vacuum test chamber. This standard does not require the introduction of additional dyestuff or gases, and can be used for various Encasement types, including Encasement for sealing of rigid, flexible, and porous barrier cover materials. The use of ASTM F 2338-09 (2020) helps to optimize Encasement sealing performance and compare the performance of different Encasement materials for online or statistical sampling testing in a production environment.