On March 27, 2026, the IAFTC hosted a webinar presented by Dr. Joseph Anderson titled Airway Gas Exchange: The Foundation of the Alcohol Breath Test. In this session, Dr. Anderson provided a detailed and research-driven examination of lung physiology as it relates to breath alcohol testing, with a focus on airway gas exchange. 

Drawing from decades of experimental data and mathematical modeling, he explained that highly soluble compounds such as ethanol do not behave like traditional alveolar gases (such as carbon dioxide), but instead undergo significant exchange within the airways. He described how the airway lining acts as a reservoir for alcohol, leading to continuous absorption and reabsorption during the breathing cycle, which challenges the assumption that breath alcohol reflects a simple alveolar equilibrium.

The presentation also explored how multiple physiological and procedural factors can influence breath alcohol results, including breathing pattern, breath temperature, exhaled volume, and lung size. Dr. Anderson emphasized that these variables can meaningfully affect measured concentrations, underscoring the importance of understanding underlying physiology when interpreting breath test data. 

The webinar provided attendees with a deeper scientific framework for evaluating breath alcohol testing and highlighted the complexity of interpreting results in forensic contexts. The webinar recording is available here: Airway Gas Exchange - The Foundation of the Alcohol Breath Test - Joe Anderson Webinar.mp4