Many current inhalers for conditions such as asthma contain propellants that are potent greenhouse gases. A study from researchers at the University of Cambridge has found that switching to alternative, greener inhalers would not only result in large carbon savings, but could be achieved alongside reduced drug costs by using less expensive brands.
Our study shows that switching to inhalers which are better for the environment could help individuals, and the NHS as a whole, reduce their impact on the climate significantly. This is an important step towards creating a zero carbon healthcare system fit for the 21st century
Metered-dose inhalers contain liquefied, compressed gases that act as a propellant to atomise the drug being delivered and to pump it out to the user. Originally chlorofluorocarbons (CFCs), were used as the propellant but these potent greenhouse gases and ozone-depleting substances are now banned. Instead they have been replaced by hydrofluoroalkane (HFA) propellants.
While HFAs are not damaging to the ozone layer, they are still potent greenhouse gases, and currently metered-dose inhalers contribute an estimated 3.9% of the carbon footprint of the National Health Service in the UK. In 2017, around 50 million inhalers were prescribed in England, of which seven out of ten were metered-dose inhalers, compared to only one in ten in Sweden.
There have been calls to switch away from HFA inhalers because of their environmental impact. Effective alternatives are already available, such as dry powder inhalers and aqueous mist inhalers. Switching to inhalers with a lower carbon footprint is a key part of the NHS Sustainable Development Unit’s strategy. However, a significant barrier to moving to alternative inhalers is the higher “up-front” price of some dry powder inhalers.
In a study published today in BMJ Open, a team of researchers studied NHS prescription data from England in 2017 and collated carbon footprint data on inhalers commonly used in England in order to compare the financial and environmental costs of different inhalers.