The carbon footprint of a respiratory inhaler varies depending on the inhaler type, with pressurised metred dose inhalers (pMDI) known to have the highest carbon footprint. Northern Sydney Local Health District (NSLHD) is implementing innovaiton recyling interventions, to support their target of net zero emissions by 2035.
Respiratory inhalers are devices containing medication to control disease and provide symptom relief for individuals with airways diseases such as asthma. Their carbon footprint is largely attributed to a greenhouse gas used to propel the medication into the airways.1 The canisters storing this propellant are overfilled, which means at the end of the inhaler’s life, up to 25% of the stored propellant remains.2 If placed in general waste, as is the current procedure, the greenhouse gas is gradually released into the atmosphere over time, contributing to global warming.
In Australia, few alternatives to pMDIs exist – therefore, the best course of action to reduce their carbon footprint is to ensure their appropriate disposal. Appropriate disposal enables the capture of the gas which can then be recycled for other uses, such as refrigeration, as well as recycling of the plastic and aluminium components.
Recycling program reduces greenhouse gas emissions
The aim of this project was to reduce the number of respiratory inhalers disposed of at Royal North Shore Hospital (RNSH) and thus entering landfill. We undertook a pilot collection of used inhalers across key wards to calculate their carbon footprint and demonstrate the feasibility of an ongoing recycling system.
We conducted a one-month audit of inhaler prescriptions of all types across RNSH departments to determine those departments with the highest usage. Following the audit, we targeted these departments for education on the emissions attributed to inhalers and introduced disposal via allocated collection bins in ward utility rooms rather than general waste. Inhalers were collected for an eight-week period and analysed.
Following this, we received approval for an expanded 12-month collection commencing in June 2024 across all inpatient wards at RNSH. Pharmacycle, a clinical waste recycler, was engaged to provide bins and facilitate the recycling process. Published lifecycle assessments of pMDIs were used to calculate their relevant carbon emissions, with adjustments made where an inhaler collected had a dose counter demonstrating its remaining contents.3
80% of inhalers collected were those with high relative carbon footprint
The eight-week pilot period and the first two months of the subsequent collection period has seen a total of 348 inhalers collected. Of these, 280 (80%) were pMDIs with high relative carbon footprint. The footprint of these pMDIs was calculated to be 3,212 kg CO2e, which is equivalent to a medium-sized petrol car driving 18,000km.4 The wards with the highest contribution to the pilot collection were respiratory (29), paediatrics (24) and cardiothoracic wards (11). 67% of the pMDIs collected in the subsequent collection so far had dose counters, and of those, only 25% had been completely used.
Ongoing assessment of the inhalers collected will occur until June 2025 as well as continued education to ensure correct disposal of inhalers and to reduce prescriptions of pMDIs. We plan to share preliminary results at district sustainability meetings as other sites have expressed interest in the program and are keen to be involved in a broader roll out.
Inhaler recycling services offered by Pharmacycle include blister pack recycling, therefore opportunities exist for combined inhaler and blister pack recycling projects. Significant carbon footprint saving can be made by appropriate disposal of pMDIs in a hospital setting, where symptom relievers are frequently used.
This project was part of the NSLHD Net Zero Leads Program.
References
- Carbon Footprints and Life Cycle Assessments of Inhalers: A Review of Published Evidence https://www.mdpi.com/20711050/14/12/7106
- Janson C, Henderson R, Löfdahl M, Hedberg M, Sharma R, Wilkinson AJK. Carbon footprint impact of the choice of inhalers for asthma and COPD. Thorax. 2020;75(1):82-84. doi:10.1136/thoraxjnl-2019-213744
- Available 10. PrescQIPP Hot Topic. Lowering the inhaler carbon footprint. Attachment 1. Inhaler comparisons including indicative carbon footprint - October 2020.xlsx. Available at: https://www.prescqipp.info/our-resources/webkits/hot-topics/
- GOV.UK. Greenhouse gas reporting: conversion factors 2023. United Kingdom; 2023. [cited Jul 2024].
