Firefighters during post-fire overhaul are exposed to elevated levels of airborne particulates, toxic gases, and carcinogenic byproducts that persist after active flames are extinguished. Repeated exposure is associated with increased long-term health risks, including respiratory disease and occupational cancer. While self-contained breathing apparatuses provide protection during active suppression, their prolonged use during overhaul contributes to physical fatigue and physiological strain.
To address this, we developed the Canary Air Purification Unit—a respirator cartridge designed to integrate directly with existing firefighter face masks and PPE. The device aims to reduce inhalation of harmful contaminants during overhaul while minimizing the physical burden of traditional respiratory protection. The final design features a dual-filter system combining a high-efficiency particulate air (HEPA) filter and a cellulose nanofiber (CNF) filter, enclosed in a lightweight thermoset epoxy casing. This configuration enables effective removal of larger particulates and fine carcinogenic particles while maintaining compatibility with standard firefighter PPE.
Design development followed a structured engineering approach driven by clearly defined performance and usability requirements. Key priorities included filtration efficiency, contaminant removal accuracy, durability under harsh conditions, and ease of adoption. These requirements were translated into quantitative engineering specifications using a House of Quality analysis, with concept selection performed via a Pugh chart. Overall, the Canary Air Purification Unit enhances firefighter safety during overhaul by reducing airborne contaminant exposure while maintaining usability and long-term applicability.