Airflow, CO2 Inhalation, and Firmness Characteristics of Commercial Infant Products

ABSTRACT This study introduces three different test methods to evaluate suffocation-related hazards in infant products that result from three specific hazards: mechanical occlusion of the nares, resistance to airflow, and abnormal gas exchange, particularly carbon dioxide (CO2) inhalation. A range of infant products and reference materials (crib mattresses, lounger pillows, mesh and traditional crib bumpers, inclined sleepers, blankets, and lambs wool) were tested using firmness testing (product deformation under 10 Newton load) to assess nasal occlusion risks, airflow testing (at 0° and 15° head rotation of a 3-inch hemispheric probe with nares) to evaluate resistance to breathing, and CO2 inhalation testing (with the same probe as airflow testing) to identify potential suffocation hazards not addressed by existing standards. Firm and flat surfaces like crib mattresses were shown to reduce suffocation hazards because light head rotations improved airflow and decreased CO2 retention. Conversely, soft, concave, or polyfilled products (lounger pillows, inclined sleepers, traditional crib bumpers) exhibited all three suffocation-related risks, with minimal improvement even with head rotation. Lambs wool, despite allowing airflow, had high CO2 retention levels, representing a significant risk for hypercapnia or hypoxia. Mesh crib bumpers demonstrated low airflow resistance and safe CO2 levels. Firmness, airflow resistance, and CO2 retention testing revealed distinct suffocation hazards in various infant products. Firm, flat surfaces mitigate risk, whereas soft or concave products increase suffocation-related dangers. This research highlights the need for comprehensive safety evaluations of infant products during the design process, particularly focusing on firmness, airflow, and gas exchange, to prevent suffocation risks in infant sleep environments.