Green inhalers: reducing the carbon footprint of asthma care

PURPOSE OF REVIEW: The respiratory community faces an urgent need to reduce the environmental impact of care as the wider climate crisis threatens to worsen airways disease worldwide. Inhalers contribute a disproportionate share of healthcare emissions because of the hydrofluorocarbon (HFC) propellants in pressurized metered-dose inhalers (pMDIs). We already have effective, low-carbon, per- and polyfluoroalkyl substances (non-PFAS) options; particularly dry-powder inhalers (DPIs). This review summarizes recent developments in propellant technology and evidence on optimizing asthma care to improve outcomes while lowering emissions. RECENT FINDINGS: Life-cycle studies confirm that pMDI emissions are dominated by propellant released during use, whereas DPIs have far lower footprints. New global warming potential (low-GWP) propellants are in advanced development, and the first inhaler using HFO-1234ze(E) has recently been licensed in the UK. Emerging clinical and prescribing data show that optimized therapy, particularly strategies that incorporate low-carbon inhalers, can reduce short-acting beta-agonist (SABA) over-reliance, exacerbations, and per-patient emissions. Guideline-driven, health-system approaches using prescribing data and formulary design can accelerate sustainable, evidence-based inhaler use. SUMMARY: The most immediate path to reducing inhaler-related emissions is to optimize asthma care while prioritizing low-carbon devices where appropriate. As low-GWP pMDIs enter the market, careful planning will be needed to ensure reliable, affordable access to pMDIs is maintained or improved globally, particularly in low- and middle-income countries.