Increasing propellant gas emissions from pressurized metered-dose inhalers in obstructive lung diseases in France...

Management of chronic obstructive respiratory diseases involves the use of inhaled therapies, including pressurized metered-dose inhalers (pMDIs) that contain hydrofluoroalkane (HFA). These propellant gases contribute to greenhouse gas emissions (GHG) due to their infrared radiation absorption capacity, resulting in a high Global Warming Potential, far higher than carbon dioxide (CO₂), contributing to climate change. The aim of this study was to estimate the carbon footprint of the propellant gases contained in all pressurized metered-dose inhalers prescribed in France, over an 11-year period.

Data were extracted from the French Health System Open Medic Database, covering 2014 to 2024. Gas quantities were obtained from the French Theriaque Database and, when unavailable, from pharmaceutical companies. Emissions were expressed as CO₂ equivalents based on their corresponding Global Warming Potential values.

Over the past decade, 500 million inhalers were dispensed, pressurized metered-dose inhalers representing 44% of them. Gas quantity data was available for 83% of the units. Over the 11-year period, total emissions reached 4.5 million MtCO₂eq. The mean annual emission was 409 ktCO₂eq, representing a 38,7% increase, particularly pronounced since 2021.

This exhaustive national study shows that pressurized metered-dose inhalers emitted more than 4,5 MtCO₂eq in 11 years, increasing annually. These findings highlight the substantial carbon footprint associated with current inhalers containing high Global Warming Potential propellant gases and underline the need to promote lower-impact therapeutic alternatives.