SUSTAINABILITY SNAPSHOT SERIES:

ENVIRONMENTALLY SUSTAINABLE OPPORTUNITIES FOR HEALTH SYSTEMS

Metered-dose inhalers (MDIs) are common medical devices used to deliver inhaled medication, typically for individuals with asthma and chronic obstructive pulmonary disease (COPD) (1)  Metered-dose inhalers are pressurized and rely on liquefied-gas propellants to atomize medication for inhalation delivery. In the past, they used chlorofluorocarbons (CFCs) as a primary gas propellant. However, chlorofluorocarbons were banned under the 1987 Montreal Protocol as they possess significant ozone-depleting properties. Soon after, pharmaceutical companies began manufacturing metered-dose inhalers that use more ozone-friendly hydrofluorocarbons (HFCs); primarily HFC-134a and, to a lesser extent, HFC-227ea (3,5). However, although hydrofluorocarbons do not deplete the ozone layer, they do have a high global warming potential (GWP), averaging 1400-3200 GWP depending on which hydrofluorocarbons propellant is considered (6). The GWP of inhaler propellants is 167 to 1550 times higher than that of carbon dioxide (CO2)(2).  

Indeed, recent studies have shown that metered-dose inhalers contain high levels of hydrofluorocarbons (HFCs) that act as potent greenhouse gases (GHGs) when released into the atmosphere, contributing to the healthcare sector’s carbon footprint. hydrofluorocarbons emissions from metered-dose inhalers mostly come from the use-phase following the end-of-life disposal when propellants are released into the atmosphere (1) The UK National Institute for Health and Care Excellence (NICE) reports that metered-dose inhalers containing 100 doses have a carbon footprint equivalent to a 180-mile car journey (7). According to a 2014 report published by the United Nations Environment Programme, hydrofluorocarbons emissions from metered-dose inhalers represent roughly 0.03% of annual global greenhouse gases emissions. The demand for metered-dose inhalers is increasing (between 2016-2017, for example, metered-dose inhalers sales increased at a rate of 4% in the Global North, and 18% in the Global South), and as it does, the hydrofluorocarbons emissions associated with their use will also increase (1,2).

Both patients and health care professionals have many opportunities to opt for more environmentally sustainable options with respect to the treatment of respiratory conditions. The following strategies may be employed individually or in combination to mitigate the environmental impact of inhalers:

1.     Encouraging alternatives to metered-dose inhalers whenever possible

2.     Ensuring appropriate inhaler usage

3.     Practicing sustainable recovery and recycling of inhalers

4.     Developing suitable prescribing practices around inhalers

View the full Inhalers Sustainability Snapshot to learn more about these sustainability interventions, and download the infographic below for a quick reference.