Since an asymptomatic worker can carry the virus, all plant staff working in close proximity with inadequate physical distancing measures in place should be equipped with at least non-medical face masks. These masks should not replace the existing workplace respiratory protection program requirements; Another type of mask or respirator may be indicated based on a task-based hazard assessment, so your respiratory protection program should be re-evaluated and revised as needed to address biological hazards such as COVID-19.
If masks are used, they should be single-use and disposed after each use, or laundered after each use in the case of non-medical fabric masks. COVID-19 can remain viable on a mask for 7 days (Lancet).