Which of the following statements about respirators is incorrect?

• A. An N100 respirator is expected to filter at least 99.97% of airborne particles but is not resistant to oils.
• B. Both an R95 respirator and a P95 respirator are expected to filter at least 95% of airborne particles, with the R95 more resistant to oils than the P95.
• C. A P99 respirator has a longer certified service life than an R99 respirator.
• D. All choices are correct.

Answer: (B)

Understanding respirator classifications helps explain why that statement isn’t correct: labels combine filtration efficiency with oil resistance. The N-series is not resistant to oil, the R-series is resistant to oil, and the P-series is oil-proof. The 95/99/100 numbers specify the minimum filtration efficiency.

The claim that a respirator with the R95 designation is more resistant to oils than a P95 is not true. The P-series is designed to be oil-proof, meaning it maintains performance in oily conditions, more so than the R-series, which is only oil-resistant but can be degraded by oil over time. That makes the statement about oil resistance order incorrect.

The other provided statements align with the general meanings: an N100 filters at least 99.97% of particles and is not oil resistant; the service life topic isn’t defined by a simple comparison between P99 and R99 in standard labeling, so that specific claim isn’t a valid differentiator based on the official ratings. Since one statement contradicts the established classifications, the overall correct choice is the one identifying that incorrect claim.