title: Nonrebreathing valve competence.
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis; D004868:Equipment Failure; D006801:Humans; D008168:Lung / Q000502:physiology; D008954:Models, Biological; D010969:Plastics; D011175:Positive-Pressure Respiration / Q000295:instrumentation; D012121:Respiration, Artificial / Q000295:instrumentation*; D012129:Respiratory Function Tests / Q000295:instrumentation
chemical_list: D010969:Plastics; D002245:Carbon Dioxide