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664 HAZWOPER for General Site Workers V
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Level B Protection (5 to 500 PPM)

Level B protection is the minimum level of protection recommended for initially entering an open site where the type, concentration, and presence of airborne vapors are unknown.

Workers wearing Level B protection in the forefront, and Level A protection in the background.

This level of protection provides a high degree of respiratory protection. Skin and eyes are also protected, although a small portion of the body (neck and sides of head) may be exposed. The use of a separate hood or hooded, chemical-resistant jacket would further reduce the potential for exposure to this area of the body. Level B impermeable protective clothing also increases the probability of heat stress.

Click on the link below to review factors that should be considered when selecting Level B protection:

  • the necessity for entering environments with unknown constituents at concentrations higher than 500 ppm wearing Level B protection;
  • the probability substance(s) present pose severe skin hazards;
  • the work to be done and the increased probability of exposure;
  • the need for qualitative and quantitative identification of the specific components;
  • inherent limitations of the instruments used for air monitoring; and
  • instrument sensitivity to winds, humidity, temperature, and other factors.

Click on the link below to review what a typical Level B ensemble includes.

  • positive-pressure (pressure-demand), self-contained breathing apparatus (NIOSH approved), or positive-pressure supplied air respirator with escape SCBA
  • chemical resistant clothing (overalls and long-sleeved jacket, coveralls, hooded two-piece chemical splash suit, disposable chemical resistant coveralls.)
  • gloves, outer, chemical resistant
  • gloves, inner, chemical resistant
  • boots, outer, chemical resistant, steel toe and shank

Knowledge Check Choose the best answer for the question.

5-9. Which level of protection is the minimum level of protection recommended for initially entering an open site where the type, concentration, and presence of airborne vapors are unknown?