Sealable air sampling bag

An air sampling device for obtaining an air sample from a person's lungs, and a method for using the same. The air sampling device is comprised of generally of a breath intake structure (22), an expandable bag structure (30), an adhesive patch (50), and a removable adhesive patch cover (60). Optionally an adhesive inlet seal patch (70) also seals either the expandable bag inlet (36) or an outer shell (90). The outer shell (90) is provided to capture the air sample should the expandable bag structure (30) fail. A person breathes into the breath intake (22), the device directing a first predetermined volume of breath into the expandable bag structure (30), and the remainder of breath also into the expandable bag (30), the remainder of the breath expelling the first predetermined volume of waste air from the expandable bag structure (30). The breath intake structure (22) and removable adhesive patch cover (60) are removed and the adhesive patch (50) seals the interior surfaces (38,40) of the expandable bag structure (30). The expandable bag stucture (30) can include preloaded desiccant or chemical indicator, in order to perform a variety of tests.