Low-GWP inhalers are coming, but the transition has to protect patients first
Pressurised metered-dose inhalers remain central to treatment for asthma, chronic obstructive pulmonary disease, and other respiratory diseases. They are also part of the climate problem. Most current pMDIs rely on hydrofluorocarbon propellants, especially HFA-134a, a gas with a 100-year global warming potential 1530 times greater than carbon dioxide. In the setting described here, that environmental burden is no longer a distant policy issue. Legislation in Europe and other developed markets is already pushing a phase-down of high-GWP propellants within the next five years, and manufacturers are developing next-generation options such as HFA-152a and HFO-1234ze[E] with far lower carbon footprints.
The clinical challenge is not whether the transition will happen. It is how to make it invisible to patients. A salbutamol pMDI with HFA-134a carries an estimated lifecycle footprint of about 27 kg CO2e, while the HFA-152a version in development is expected to fall to 2.1 kg CO2e, a 92% reduction. Even so, inhaler choice cannot be reduced to emissions alone. Dry-powder inhalers and soft-mist inhalers have low or negligible propellant-related footprints, yet not every patient can use them, and not every medicine is available in those formats. Some patients also prefer pMDIs, and reliever inhalers such as salbutamol are widely prescribed in that device class.
The transition therefore has to preserve treatment continuity while lowering emissions. Any policy that forces abrupt switching risks creating unnecessary instability in day-to-day respiratory care.
Patient safety, access, and device familiarity sit at the center of the framework
A policy roundtable brought together 28 stakeholders from the respiratory community, including clinicians, pharmacists, respiratory societies, patient groups, WHO representatives, and industry participants from multiple countries. From those discussions came four guiding principles, beginning with patient safety and seamless continuity of access. The logic is straightforward: the device only works if the patient can obtain it, use it correctly, and trust it enough to take it as prescribed.
Clinical appropriateness remains the first filter. Inhaler selection depends on disease severity, device technique, sensory preferences, and a clinician’s knowledge of the available options. During the transition, patients should continue to have access to inhalers that are effective, well tolerated, and suitable for their needs. Payer and procurement decisions should therefore involve clinical input rather than being handled purely as purchasing exercises.
A patient who notices a different taste, smell, temperature, or spray force may interpret the switch as a change in efficacy, even when the medicine remains therapeutically equivalent. That is a small sensory detail with a large behavioral consequence. For that reason, the framework argues for a transition that feels seamless from the patient’s perspective, with clear education focused on inhaler technique and essential use instructions rather than extensive retraining.
Patients could not reliably distinguish between pMDIs using high- and low-GWP propellants in the information cited here. That finding matters because it suggests that, with appropriate communication, the switch need not become a barrier to adherence or confidence.
Supply chain resilience will determine whether the transition stays orderly
The second principle is securing supply through shared responsibility and collaboration. The propellant market is concentrated, which creates vulnerability at exactly the moment the system needs flexibility. As HFA-134a volumes fall, its cost is expected to rise, and eventually access to that propellant will no longer be possible. The article also points to a supply structure in which most global HFA-134a propellant is manufactured by a single company in the United Kingdom and exported in bulk for inhaler manufacture in Europe, where roughly half of the world’s pMDIs are produced.
Supply fragility is not a side issue. If current and future propellants are not overlapped carefully, patients can face shortages, abrupt product changes, and fragmented access across countries. The transition also has to account for the fact that low-GWP propellant manufacturing is still developing, with production starting in India and China and regulatory approval of new GMP-standard propellants able to take several years.
The article calls for shared accountability across manufacturers, health systems, clinicians, professional societies, patient groups, payers, regulators, and WHO. Each group has a different role, but none can manage the transition alone. Industry must plan phased introductions and discontinuations and share information transparently. Clinicians and societies should lead clinical guidance and training. Patient groups should help shape communication materials so that they reflect real patient concerns. Payers and procurement bodies should coordinate with clinical and regulatory stakeholders so that formulary changes do not arrive as abrupt shocks to care.
Low- and middle-income countries remain especially vulnerable here, but high-income systems are not immune. Access to essential inhaled therapy can be disrupted in both settings when supply chains are tight or policy moves faster than manufacturing capacity.
Regulation and communication need to move at the same pace as the technology
The third principle is alignment of regulatory and policy interventions across jurisdictions. Multiple overlapping frameworks, including those tied to fluorinated gases and PFAS, raise the risk of fragmented implementation. Regulatory agencies are urged to coordinate across health and environment portfolios and to provide consistent, timely, proportionate guidance. Where low-carbon alternatives are not yet available, medical exemptions or phased approaches should remain on the table to protect access to medicines that are clinically necessary.
Clear timelines matter here because manufacturers need predictable roadmaps, and health systems need time to prepare. Without them, uncertainty can lead to delay on one side and rushed decisions on the other. Both are bad for patients.
The fourth principle is credible clinician- and patient-centred communication. Trust is not a soft add-on; it is part of the mechanism that determines whether patients continue treatment during a device transition. If patients lose confidence, adherence can fall, disease control can worsen, and exacerbations may increase. The article links that concern to the broader reality that suboptimal asthma care is associated with greater symptom burden, more exacerbations, and higher rates of emergency care and hospitalisation.
For clinicians, the practical requirement is simple but demanding: explain the switch clearly, keep advice consistent, and avoid implying that the medicine itself has become less reliable. For patients, the message should be equally direct: the goal is to preserve the same therapeutic benefit while moving to lower-carbon inhalers where appropriate. Environmental commitments and clinical care do not sit on opposite sides of the equation, but the transition will only work if patient safety stays visible in every procurement decision, regulatory timetable, and bedside conversation.