This study aimed to determine the efficacy of using face masks (e.g., surgical masks) to decrease transmission of SARS-CoV-2. Their analysis revealed that the efficacy of face masks is dependent on the virus abundance and the probability of infection. Masks were found to be effective in removing large droplets and decreasing the number of inhaled viruses under low-virus environments. Masks were less effective in virus-rich environments such as hospitals. Authors conclude that most environments have a low virus abundance and therefore face masks are effective in preventing the transmission of SARS-CoV-2. Environments with high virus abundance should utilize high-efficiency masks (e.g., N-95/FFP2 masks), social distancing, and ventilation to prevent the spread of SARS-CoV-2.