Asthma is a chronic respiratory condition that, according to GlobalData’s Epidemiology Database, affects approximately 14% of the UK population, and almost 88 million people in the seven major markets worldwide (US, UK, France, Germany, Italy, Spain, and Japan). Common symptoms include wheezing, shortness of breath, and limited airflow, which can vary in severity. Asthma is typically treated with a combination of a maintenance inhaler for everyday use and a rescue inhaler for symptom relief during asthma attacks.
Commonly, inhalers will be pressurized metered dose inhalers (pMDIs), which use chemical propellants to administer the dose. However, these propellants have a carbon footprint. Before their ban, chlorofluorocarbons (CFCs) were used as the propellant in most inhalers, which both contributed to the greenhouse effect and caused significant damage to the ozone layer. They have since been replaced with related hydrofluorocarbons (HFCs), and while they do not deplete the ozone, are still powerful greenhouse gases (GHGs), and therefore have a carbon footprint. As the gas emitted is not CO2, this footprint is measured in CO2 equivalent kilograms (CO2e kg). According to the National Institute of Health and Care Excellence (Nice) Patient Decision Aid: Inhalers for Asthma guidance, one dose from a pMDI (0.5 CO2e kg) is comparable to driving almost two miles in a typical car (0.58 CO2e kg) (Figure 1). In addition, according to the UK’s National Health Service’s (NHS) Delivering a ‘Net Zero’ National Health Service report from 2020, the HFCs used as propellant in inhalers account for 3-4% of the healthcare related carbon footprint in the UK.



