A new cross-sectional analysis estimates that asthma inhalers contribute the same carbon emissions as 530,000 cars each year. That's over over 2 million metric tons of greenhouse gases annually from the three types of inhalers approved for asthma or COPD during the years 2014 to 2024. 

Metered-dose inhalers are the most harmful to the environment, they write, accounting for 98 percent of emissions over the ten-year period. They call those out because metered-dose inhalers contain hydrofluoroalkane (HFA) propellants common in aerosol sprays but which have been targeted by environmental groups as potent greenhouse gases. The other types of inhalers, which include dry inhalers and soft powder mist inhalers, do not escape blame but since they don't need propellants to deliver medication to the lungs they are considered less harmful to the environment.

Ironically, the authors say inhalers are creating more risk for asthma and COPD patients, by increasing climate change. 


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The conclusion was determined by taking federal government data on U.S. inhaler prescriptions at the National Drug Code (NDC) level. The data included drug type, device type, propellant type, therapeutic class, branded status, manufacturer, payer, and pharmacy benefit manager. Then they estimated emissions using other academic numerical model, so this is only EXPLORATORY. 

They next want to analyze inhaler-related emissions in specific patient populations, such as the Medicaid population. That could lead to class distinctions if the poor and elderly are told they can't have what works, while the rich still get it.

Citation: Feldman WB, Han J, Raymakers AJN, Furie GL, Chesebro BB. Inhaler-Related Greenhouse Gas Emissions in the US: A Serial Cross-Sectional Analysis. JAMA. Published online October 06, 2025. doi:10.1001/jama.2025.16524