Carbon Footprints and Life Cycle Assessments of Inhalers: A Review of Published Evidence

Abstract

Respiratory inhalers have a substantial impact on the carbon footprint of the healthcare sector. Environmental factors, including carbon footprints, are gaining importance in choosing inhalers once medical considerations have been addressed. This paper provides a review of the carbon footprint (CFP) and life cycle assessment (LCA) environmental profile of dry powder inhalers (DPIs) and pressurized metered-dose inhalers (pMDIs). Despite methodological challenges, our analysis reveals that the CFP varies between DPIs ranging from 359 gCO2e per inhaler (Enerzair Breezhaler® DPI without digital companion 30-day pack) to 1250 gCO2e per inhaler (Seretide Accuhaler® 50/500) and from 6.13 gCO2e per dose (Enerzair Breezhaler® without digital companion 90-day pack) to 27 gCO2e per dose (Relvar Elipta 92/22). The breakdown of inhaler CFP by life cycle stage reveals that, although the use and end-of-life stages together contribute to most of the CFP of the MDIs, the largest contributions to the CFP of the DPI/SMI are made by the API and manufacturing stages of the life cycle. Although from a climate perspective our review aligns with the findings of Jeswani and Azapagic that DPIs have a lower CFP than pMDIs, we conclude that the performance against other environment impact categories depends on the design, choice of material and manufacturing process of the DPIs. The challenge of comparing the CFP of different inhalers can be made easier by the standardization of study boundaries and methods.