A surgical mask, bandana, cloth mask, or dirty T-shirt over a particulate mask (e.g. N95) is typically allowed. There are serious benefits to the wearer to havi

A surgical mask, bandana, cloth mask, or dirty T-shirt over a particulate mask (e.g. N95) is typically allowed. There are serious benefits to the wearer to having an exhaust valve. Wearing a second, less effective face covering over the particulate mask retains the benefits of the particulate mask and exhaust valve while maintaining the same level of source control as without the particulate mask.