Inhaler carbon footprint.
A single metered-dose inhaler's propellant outweighs its medicine in carbon terms. The switch to dry-powder is the biggest prescribing decision in medicine, carbon-wise — and it is now colliding with European PFAS legislation.
Every action, graded.
Evidence grades travel with every claim. Click through to the study behind each number.
| ID | Action | Evidence | CO₂e / yr |
|---|---|---|---|
| ACT-031 | Switch eligible asthma patients MDI → DPI Inhaler switching programmes — Current Medical Research and Opinion 2026, DOI 10.1080/03007995.2026.2628120 |
Strong RCT / dept data | 146 t/yr |
| ACT-032 | Balance the switch against access risk — read IRIS first IRIS call to action — European Respiratory Journal 2026, DOI 10.1183/13993003.01873-2025 |
Strong RCT / dept data | context |
| ACT-033 | Brief prescribers on the EU PFAS timeline Global pMDI use + PFAS — Pulmonary Therapy 2026, DOI 10.1007/s41030-026-00362-1 |
Cohort / modelling | context |
| ACT-034 | Use the risk/reward framing with patients pMDI→DPI risk & reward — Pulmonary Therapy 2026, DOI 10.1007/s41030-026-00355-0 |
Cohort / modelling | qual. |
| ACT-035 | Recycle returned inhalers via pharmacy take-back Frontiers/CMRO reviews, disposal sections — see department sources |
Estimated — local audit needed | est. |
Before you start.
Propellant, not care
The switch changes the device, not the treatment plan. Say this to every patient.
Data you already have
Prescribing systems hold the MDI/DPI ratio by GP practice — that's your baseline.
No switch without a clinical indication.
Every action on this page passes through this gate.
The counter-evidence on this page is the whole point: non-clinically-driven switch policies lost 65–70% of their projected savings to exacerbations. The inhaler in the hand that controls the disease is the low-carbon inhaler. Eligibility review is not a step on the way to the carbon target; it is the carbon target.
What the data shows.
The counter-evidence, honestly stated.
A 2026 UK/Sweden/Denmark model of non-clinically-driven DPI switches found the savings far smaller than hoped: COPD exacerbations from poorer control offset 65–70% of the anticipated inhaler savings — and once next-generation-propellant pMDIs arrive (2026+), continuing forced-switch policies would raise total emissions 12–13×. Checking eligibility first isn't red tape — it is the whole reason the switch saves anything at all.
Current Medical Research and Opinion 2026 · DOI 10.1080/03007995.2026.2628120
Asked and answered.
How big is the inhaler slice?
MDI propellants are the largest single slice of primary-care prescribing emissions; pMDIs made up 77.3% of global inhaler use in 2022 and exceed 50% in 51 of 55 countries with data. This is a decision that matters at national scale.
Should every eligible patient switch to DPI?
Eligible patients, yes — programme measurements show ~146 t CO₂e/yr per average English trust. But blanket-switching every patient is where the savings invert (see the counter-evidence above). The IRIS consensus and the risk/benefit framework action exist for exactly this reason.
What changes with EU PFAS rules?
Legislation may force propellant reformulation regardless of clinical preference. The Pulmonary Therapy analysis maps which pMDIs stay available per country — prescribing committees should read it before 2027 planning.