What is the recommended minimum PPE when working in an atmosphere of less than 19.5% oxygen with additional hazards?

When working in an atmosphere with less than 19.5% oxygen, along with additional hazards present, the recommended minimum personal protective equipment (PPE) is Level B. This classification is appropriate because Level B protection offers a higher level of respiratory protection and chemical resistance compared to Levels C and D.

Level B includes a positive pressure self-contained breathing apparatus (SCBA) or a positive pressure air line with auxiliary escape, which is vital in environments where oxygen deficiency is a concern. The chemical protective suit used in Level B also provides more comprehensive coverage from hazardous materials than Levels C and D, which are suitable for less hazardous situations. Therefore, in environments with both oxygen deficiency and associated hazards, Level B is the optimal choice to ensure the safety and health of workers.