One of the less obvious contributors to global warming is right in many patients medicine cabinets. A new study finds that asthma inhalers in the United States generate greenhouse gas emissions equivalent to those produced by 530,000 cars per year which reveals a hidden environmental cost in treating respiratory disease. In the past decade, inhalers in the U.S. were responsible for roughly 24.9 million metric tons of CO₂ equivalent emissions i.e. 98 % of which came from metered-dose inhalers (pMDIs) using hydrofluoroalkane (HFA) propellants.
Why They Emit So Much?
Propellant gases: pMDIs rely on pressurized propellants (hydrofluoroalkanes) to deliver the drug dose. These gases have high global warming potential.
Remaining gas waste: Even after the active medicine is used, leftover propellant in inhalers can continue to leak into the atmosphere.
Device prevalence: pMDIs remain the dominant type in many places, especially for certain age groups or for patients who cannot generate enough inhalation force for dry powder inhalers (DPIs).
DPIs and soft mist inhalers don’t rely on propellants, which dramatically lowers their emissions. In fact, in comparisons, these “propellant-free” inhalers can reduce carbon emissions by 90% or more (depending on the model and use).
“The very devices that help us breathe easier are quietly warming the planet, a reminder that even lifesaving care carries a climate cost.”
A Delicate Balance between Health vs Environment?!
Switching inhalers isn’t always straightforward. Some patients especially small children or elderly people with weak lung capacity may struggle to use DPIs effectively. Also, cost and insurance coverage can be barriers like In U.S., many greener inhalers are more expensive or not well covered. Medical decisions must prioritize efficacy, safety, and patient adherence, the climate impact is important but secondary in clinical choice.
Policy, Practice & Innovation:
Prescribe greener inhalers where clinically appropriate
Covering lower-emission inhalers as standard could remove financial disincentives.
Training on inhaler technique can cut emissions .
Some pharmaceutical companies are developing new propellants with far lower global warming potential, so need for more research.
Proper disposal of used inhalers can reduce residual emissions.
Governments can encourage or mandate transitions, set emissions standards for inhaler devices, and incentivize innovation.
If we look ahead, climate change itself is worsening respiratory conditions , so the demand for inhalers may grow. It’s urgent to build sustainable systems now. The goal isn’t to limit care, but to deliver respiratory health more sustainably.