The ASTM F 2476-20 standard provides a method for measuring carbon dioxide gas transmittance (CO2TR) using an infrared detector. This method is suitable for evaluating the steady-state carbon dioxide transport rate of various barrier materials such as films, flakes, laminates, and plastic-coated materials. The test results include carbon dioxide gas transmittance, membrane permeability to carbon dioxide gas, and permeability coefficient. CO2TR is an important factor in judging the protective performance of Encasement materials, but it is usually necessary to combine Miscellaneous testing to fully evaluate Encasement effect. This method is also suitable as a referee test method, provided that the buyer and seller agree on the sampling, test conditions, and standards. Users should establish appropriate safety practices and comply with relevant regulations.