Which designation indicates a filter is not resistant to oil?

Which designation indicates a filter is not resistant to oil?

• A. R
• B. N
• C. P
• D. A

Answer: (B)

In respirator filters, the letters describe how the media handles oil aerosols. Not resistant to oil is indicated by the designation that means the filter is not oil-resistant. That label is N, because N stands for not oil resistant. The other labels show some oil resistance: R indicates oil resistance (usable in oily environments for a limited time), and P indicates oil-proof (high resistance to oil). So the reason the chosen designation is the best answer is that it explicitly signals no tolerance to oil exposure, which is why it would not be suitable in oil-containing environments.

In respirator filters, the letters describe how the media handles oil aerosols. Not resistant to oil is indicated by the designation that means the filter is not oil-resistant. That label is N, because N stands for not oil resistant. The other labels show some oil resistance: R indicates oil resistance (usable in oily environments for a limited time), and P indicates oil-proof (high resistance to oil). So the reason the chosen designation is the best answer is that it explicitly signals no tolerance to oil exposure, which is why it would not be suitable in oil-containing environments.