B TO THE EDITOR: b Many professionals, including those who have expertise in aerosol science and respiratory protection, have expressed concern about the "ethical nature" of Loeb and colleagues' study ([1]). A letter ([2]) concerning the trial design as published at ClinicalTrials.gov was sent in April 2021 to the Canadian Government, Responsible Conduct of Research, Tri-council Federal Office, from occupational health and safety professionals located around the world. [Extracted from the article]