OBJECTIVES : NHS England aims to achieve net-zero carbon emissions by 2040, and has targeted a 50% reduction in the emissions generated by inhalers by 2028, by encouraging a rapid prescribing switch from pMDIs to DPIs. Current policies only cover non-salbutamol inhalers, despite these generating approximately 58% of inhaler emissions in the UK. New low global warming potential (GWP) propellents, such as hydrofluroalkane (HFA)-152a, can greatly minimise emissions from both salbutamol and non-salbutamol pMDIs. This report undertook an independent assessment of the potential overall economic and carbon emissions impact of the current NHS rapid switchover policy and the potential impact on the introduction of a new low GWP propellent for pMDIs from 2025 onwards.

METHODS : An economic model compared: Business as Usual (BAU), where no switchover is implemented; the current NHS target to reduce inhaler emissions by 50% by 2028; and a slower switchover at half this rate.

RESULTS : Compared with the BAU scenario, the current rapid switchover could add an estimated £460 million to NHS expenditure in the form of higher drug purchase costs; achieve negligible emissions savings; and potentially lead to a range of unnecessary negative health impacts and additional healtcare costs estimated at £76 million. The results are driven by the policy’s potential impact on investment in low GWP propellants, such as HFA-152A, impacting emissions reductions arising from their introduction in salbutamol and non-salbutamol pMDIs.

CONCLUSIONS : To achieve the greatest emissions reduction, with the fewest negative consequences, the NHS policy must consider the salbutamol market and the timeline, carbon reductions and impact on the inhaler market from the introduction of low GWP propellents. It must incentivise investment in low GWP propellants, such as HFA-152, considering the full patient pathway and the inhaler lifecycle. Finally, it must consider wider impacts, particularly on patient health, within sustainability assessments and targets.