Which statement is true about respiratory protection?

• A. Filters are classified only by color
• B. Filters are classified on the basis of oil degradation resistance and filter efficiency
• C. Respirators are optional for most applications
• D. All filters are the same

Answer: (B)

Filters are classified on the basis of oil degradation resistance and filter efficiency. Oil resistance tells you whether a filter maintains performance when oil aerosols are present, with categories like not resistant, some oil resistance, and oil proof. Filter efficiency indicates how much of the particles the filter can capture, typically expressed as 95, 99, or 99.97 percent, and is combined with the oil resistance to form designations such as N95, R99, or P100. This dual rating guides selection for pesticide work, where you may face oily aerosols and need a level of protection appropriate to the exposure. Colors do not define performance, and not all filters are equal—there are different types and cartridges for particulates versus gases or vapors, with some requiring specific chemical cartridges in addition to particulate filters. Respirators are not optional in many pesticide applications; choosing the right filter or cartridge is essential to meet safety standards and labeling requirements.