Medline Surgical Face Masks, Blue, 300/Box (NON27402)

NIOSH rating, developed by the National Institute for Occupational Safety and Health (NIOSH), indicates how effective the respirator is at filtering aerosols and protecting the wearer. The NIOSH rating has three classifications indicating the respirator’s resistance to oil-based aerosols (N – not resistant to oil, R – resistant to oil, P – oil proof), along with its minimum efficiency percent (e.g. N95).