Nebulizer treatment with bronchodilators for patients with COVID-19 may not be safe due to the generation of aerosols with the risk that droplets will remain in the air. For this reason, delivery of these drugs using metered-dose inhalers (MDIs) tends to be preferred. Maintaining supplies of MDIs at this time of critical need is vital when demand has increased to mitigate the symptoms of COVID-19 and use of these inhalers has increased markedly with a significant increase in global demand for MDIs.
Explanatory note: MDIs use HFCs as the propellant, mainly HFC-134a. More information about MDIs is here