Gases from Asthma Inhalers Cause Negligible Warming

From The CO2 Coalition

Frits Byron Soepyan

January 2025

Abstract:

Various educational and medical institutions, as well as policymakers, have expressed concerns regarding the use of metered-dose inhalers to prevent or treat shortness of breath associated with asthma and chronic obstructive pulmonary disease (COPD), as these inhalers use hydrofluorocarbons (HFCs), which are greenhouse gases, as propellants. In response, “environmentally friendly” alternatives to metered-dose inhalers have been proposed for patients with asthma. To determine if prescribing these alternatives is necessary, we used the concentration and radiative forcing of the HFCs that are used as propellants (HFC-134a and HFC-227ea) in current inhalers to predict the temperature rise caused by the continued emissions of these HFCs into the atmosphere. Based on our estimates, the continued emissions of these HFCs would cause a combined temperature increase of about 0.0132 °C in 50 years and of about 0.0264 °C in 100 years. Such a rise in temperature is negligible and cannot be measured or felt. Therefore, curbing the emissions of HFCs from inhalers is unnecessary and would have minimal effect on the climate. Given this conclusion, the selection of inhalers to prescribe to patients with asthma or COPD should be based on the health, safety and needs of the patients, rather than on a purported environmental benefit.

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