Indicative carbon footprint of commonly prescribed MDIs by inhaler class
| Class of inhaler (and most commonly prescribed inhaler in this class) | Indicative amount of HFA propellant per inhaler (g) | Global warming potential of HFA (over 100 years)17 | Carbon footprint of inhaler (g CO2e) (range and midpoint in brackets) | Actuations per inhaler | Carbon footprint per actuation (g CO2e) | Source |
| Small volume SABA (eg, Salamol) | 6.68–8.5 | 1300 | 8680–11 050 (9870) | 200 | 43.4–55.3 (48.6 in life cycle analysis7 | Published carbon footprint study9 Inhaler performance study20 patent49 |
| Large volume SABA (eg, Ventolin) | 17.32–19.8 | 1300 | 22 520–28 000 (25 260) | 200 | 112–129 | Inhaler performance study,20 patents,21 22 independently certified study23 |
| SAMA (eg, Atrovent) | 11 | 1300 | 14.3 kg (total product carbon footprint 14.59 kg) | 200 | 71.5 | Product carbon footprint published by manufacturer14 |
| LABA (eg, Salmeterol) | 12 | 1300 | 15 600–19 000 (17 300) | 120 | 130 | Patent,50 independent study23 |
| ICS (eg, Clenil) | 11.32–20 | 1300 | 14 700–26 000 (20 350) | 200 | 73.5–130 | Patents,24 25 independently certified study23 |
| HFA134a ICS/LABA (eg, Fostair) | 12–18.2 | 1300 | 15 600–23 700 (19 650) | 120 | 130–197 | FDA report,26 patent,21 independently certified study23 |
| HFA 227ea ICS/LABA (eg, Flutiform) | 11 | 3320 | 36 500 | 120 | 295 | Patent27 |
HFA, hydrofluoroalkane; HFA134a, 1,1,1,2-tetrafluoroethane; HFA227ea, 1,1,1,2,3,3,3-heptafluoropropane; ICS, inhaled corticosteroid; LABA, long-acting beta-agonist; MDI, metered-dose inhaler; SABA, short-acting beta-agonist; SAMA, short-acting muscarinic antagonist.