What factor most limits the degree of protection provided by a respirator?

• A. The color of the respirator.
• B. The fit of the face piece on the individual's face.
• C. The duration of use.
• D. The type of cartridge.

Answer: (B)

The most important factor is how well the facepiece seals to the wearer’s face. A tight, consistent seal is what forces all inhaled air to pass through the filter material; if the seal leaks, contaminated air can bypass the filters entirely, dramatically reducing protection regardless of the filter or cartridge quality. Facial features, facial hair, movement, and the chosen respirator size or style all affect fit, so fit testing and a user seal check before use are essential to ensure adequate protection. The color of the respirator and how long you wear it don’t determine protection as directly as fit does, and while the cartridge determines what contaminants are filtered, that only helps if the seal is airtight.