Greater Glasgow and Clyde Medicines

Sustainability: Reducing the environmental impact of inhalers

Key messages

• The carbon footprint of inhalers was considered during the recent review of the NHSGGC COPD and adult asthma inhaler device guides (IDGs). The IDGs now have a traffic light key which highlights if the inhaler has a very high, high or low carbon footprint.
• Healthcare professionals can help reduce the environmental impact of inhalers by referring to the detail below on:
  • improving the management of respiratory conditions to reduce the overuse of short-acting beta₂ agonists (SABAs)
  • using lower carbon alternatives where appropriate
  • safe disposal and reduction of waste

Background:

• In 2018, propellants from pressurised metered dose inhalers (pMDIs) were estimated to account for 4% of the entire carbon footprint of the National Health Service (NHS) in the UK or 850,000 tonnes of CO₂ emissions which exceeds the entire carbon footprint of some small nations.
• The NHS long term plan has committed the NHS to reducing greenhouse gas emissions from inhalers, with a target to reduce the carbon impacts of inhalers by 50% by 2030.
• pMDIs contain the Hydrofluoroalkane (HFA) propellants HFA134a and HFA227ea which are powerful greenhouse gases with high global warming potential (GWP) and are respectively 1300 and 3350 times more potent than CO₂.
• Dry powder inhalers (DPIs) and soft mist inhalers do not contain propellant and therefore have a much smaller carbon footprint. It has been reported that DPIs have a carbon footprint 18 times lower than pMDIs.
• SABA use drives around 70% of greenhouse emissions from inhaler devices in the UK and the overuse of SABA relievers is responsible for 250,000 tonnes of CO₂ annually.
• The GWP of Ventolin Evohaler® (which is classed as a large volume inhaler) is more than double that of the small volume salbutamol pMDI Salamol®. Ventolin® pMDI has an estimated carbon footprint equivalent per dose to driving about a mile in a small car. Over a year this would be equivalent to 205KgCO2e, in comparison with 9.5KgCO2e for the Ventolin Accuhaler®, which is a DPI.
• The UK has a high proportion of pMDI use (70%) compared with the rest of Europe (50%) and Scandinavia (10-30%). This variation suggests that there are clinically appropriate means by which to reduce the level of pMDI prescribing in the UK.

How can this be achieved?

Improved diagnosis and management of respiratory conditions

• Early and accurate diagnosis of respiratory conditions.
• Encourage non-pharmacological measures e.g. pulmonary rehabilitation, smoking cessation and flu immunisation.
• Reduce overuse of SABA via improved patient education, improving inhaler technique, encouraging patients to take their preventer therapy as prescribed, promoting self-management and the use of spacers if appropriate. Well controlled patients with asthma should need SABA no more than 3 times per week, or 2 inhalers per year.

Use of lower carbon alternatives where clinically appropriate

• Information on the carbon impact (very high, high and low) is now readily available using the key on the new IDGs and should be consistently considered an aspect of shared decision making in device selection.
• The IDGs have a dry powder/soft mist inhaler option at each step of the treatment guide and this is the preferred option if appropriate for the patient.
  The GGC Respiratory Managed Clinical Network (MCN) do not advocate mass switching of pMDIs to DPI/soft mist inhalers and any change to inhalers should be tailored to the individual and should be done in agreement with the patient and their healthcare professional. It is important that the role of pMDIs in emergency care and paediatrics is recognised and also that some patients may lack the inspiratory effort, manual dexterity etc, required to use a DPI effectively.
• If a pMDI is necessary, avoid where possible, prescribing of inhalers that contain HFA227ea propellant (eg Flutiform® and Symbicort® pMDI) due to the higher carbon footprint and avoid large volume pMDIs.
• Prescribe inhaled corticosteroids to minimise the number of puffs required for the same dose. The pMDI option for low dose inhaled corticosteroid on the asthma IDG is now Clenil® Modulite 200micrograms one puff twice daily instead of Clenil®Modulite 100micrograms two puffs twice daily as this reduces the number of puffs being used daily and thereby reduces the carbon footprint by half.
• The IDGs promote the use of combination inhalers where appropriate and this can reduce the carbon footprint compared to prescribing individual inhalers.

Disposal and reducing waste

• Patients should be encouraged to return inhalers to community pharmacies for disposal or recycling. Even when there are no doses left in a pMDI, they still contain significant amount of propellant which can be released into the atmosphere and contribute to global warming. Incineration thermally degrades HFAs into far less potent greenhouse gases.
• Patients should be encouraged to order inhalers only when they need them and not to stockpile. Patients should be educated on how many doses are in each inhaler and how to identify how many doses are left.

For further information, refer to the following links:

• British Thoracic Society. Position statement: The environment and lung health. 2020. 
• NHS Scotland, Chief Medical Officer annual report 2020 to 2021. 
• Wilkinson AJK, Menzies-Gow A, Sawyer M, et al. An assessment of short-acting β2-agonist (SABA) use and subsequent greenhouse gas (GHG) emissions in five European countries and the consequence of their potential overuse for asthma in the U.K. BTS Oral Abstract No: S26. 
• Wilkinson AJK, Braggins R, Steinbach I, et al. Costs of switching to low global warming potential inhalers. An economic and carbon footprint analysis of NHS prescription data in England. BMJ Open 2019.

Published: 09/11/2021. Links updated 09/03/2022.

Medicines Update blogs are correct at the time of publication.