What is the breathing zone in workplace sampling?

What is the breathing zone in workplace sampling?

• A. Within about 6 inches of the face
• B. Within about 12 inches of the face
• C. In the far field away from the worker
• D. In the ventilation duct

Answer: (B)

The breathing zone is the air immediately around the worker’s nose and mouth from which air is drawn during breathing. For practical sampling, this zone is considered to extend roughly within 6 to 12 inches of the face, with about 12 inches being a common standard. Placing a sampler in this vicinity ensures the air collected reflects what the worker actually inhales, including any airborne contaminants released by nearby processes. If the sampler is farther away, the air is more diluted by room air and may underestimate exposure; if it’s placed in a ventilation duct, it’s measuring air in the duct rather than the air the person breathes. Therefore, sampling within about 12 inches of the face best matches the inhaled air and is the correct approach.

The breathing zone is the air immediately around the worker’s nose and mouth from which air is drawn during breathing. For practical sampling, this zone is considered to extend roughly within 6 to 12 inches of the face, with about 12 inches being a common standard. Placing a sampler in this vicinity ensures the air collected reflects what the worker actually inhales, including any airborne contaminants released by nearby processes. If the sampler is farther away, the air is more diluted by room air and may underestimate exposure; if it’s placed in a ventilation duct, it’s measuring air in the duct rather than the air the person breathes. Therefore, sampling within about 12 inches of the face best matches the inhaled air and is the correct approach.