To generate a properly inflated collection bag, the user should hold the uncapped collection bag by the stem of the mouthpiece–valve (Illustration 3a).
Then, the patient should inhale comfortably, hold breath for 10 seconds, exhale a small amount in the room, and then immediately put their mouth to the valve and exhale thoroughly into the bag (Illustration 3b). The patient must breathe out a small bit of air first so the bag will fill from their lungs and not their mouth. As soon as the user has exhaled fully, they should quickly put the cap onto the mouthpiece-valve and twist the cap clockwise until it has reached a stop. (Illustration 4).
Alternatively, the patient can follow the steps above and quickly hand the bag to the person overseeing the collection. The person overseeing the collection should hold the uncapped collection bag by the stem of the mouthpiece–valve, quickly put the cap onto the mouthpiece-valve and twist the cap clockwise until it has reached a stop. The bag should be closed right away. Holding the bag or pressing on the bag without closing the cap may cause the bag to deflate (Illustration 5). If by chance this happens, the patient can remove the cap by twisting left (counterclockwise) and recollect the sample.