Which type uses negative pressure created by breathing and requires a good seal?

Which type uses negative pressure created by breathing and requires a good seal?

• A. Airline Respirator
• B. Atmosphere-supplying Respirator
• C. Negative-Pressure APR
• D. Self-Contained Breathing Apparatus

Answer: (C)

Negative-pressure air-purifying respirators work by pulling air through filters as you inhale, which creates a small vacuum inside the facepiece. Because the air you breathe must come through the filters, a good seal around the face is essential to prevent unfiltered air from leaking in around the edges. If the seal isn’t tight, gaps will let air bypass the filters and protection drops. The other types deliver air from a source or stored supply and don’t rely on your inhalation to generate airflow through filters, so they don’t depend on a breathing-generated negative pressure.

Negative-pressure air-purifying respirators work by pulling air through filters as you inhale, which creates a small vacuum inside the facepiece. Because the air you breathe must come through the filters, a good seal around the face is essential to prevent unfiltered air from leaking in around the edges. If the seal isn’t tight, gaps will let air bypass the filters and protection drops. The other types deliver air from a source or stored supply and don’t rely on your inhalation to generate airflow through filters, so they don’t depend on a breathing-generated negative pressure.