N95 masks are not necessary for protecting against Covid transmission in non-hospital settings. A N95 mask is a prudent PPE choice when a pathogen can spread through dry, suspended particles in the air; it is very rare that bacteria or viruses can survive in such a way but there are a few that can, such as Tuberculosis. There is currently no evidence that SARS-CoV2 spreads this way. This virus is not resistant to drying, and so without moisture carrying it through the air, virions will die. Both cloth and surgical masks are effective at preventing the respiratory droplets that carry SARS-CoV2 from entering the shared air from the respiratory tract (if the patient is wearing one), and entering the respiratory tract from the air (if a non-patient is wearing one), with higher efficacy of the former than the latter.
So, N95s are not needed outside of an ICU setting. In an ICU setting, it makes sense to wear N95s in certain situations because certain equipment with high air pressure is capable of creating much higher concentrations of virus-containing aerosols than would otherwise be present, even if the patient was coughing nonstop. So, if a patient requires frequent open suctioning of airway secretions, is intubated (or being extubated), on NIPPV, needs CPR, etc., a healthcare worker should wear a N95. Otherwise, this is unnecessary.
I’m a hospital worker.